Dan Ferrell writes about do-it-yourself car maintenance and repair. He has certifications in automation and control technology.
Problems That Can Be Caused by a Failing Camshaft Position Sensor
A failing camshaft position sensor (CMP sensor) can produce a confusing range of problems, depending on the way it fails and the model of the car:
- On some vehicles, a failing camshaft sensor may lock the transmission in a single gear until you turn off and restart the engine. This cycle may repeat intermittently.
- If the sensor begins to fail while your car is moving, you may feel the car jerking while losing power.
- You may experience a noticeable loss of engine power. For example, the engine can't accelerate above 35mph.
- The engine may stall intermittently.
- You may notice poor engine performance including irregular acceleration, misfiring, hard starting, or surging.
- On some car models, a failed CMP sensor will prevent the ignition from making a spark, so that the engine won't start at all.
I. A Camshaft Position Sensor Can Fail Without Warning
II. What Is a Camshaft Position Sensor?
III. How the Sensor Can Fail
IV. CMP Codes and What They Mean
V. Camshaft Position Sensor Location
VI. CMP Sensor Troubleshooting
VII. Video: Testing a Camshaft Position Sensor
VIII. What If My CMP Sensor Seems to Be Working Find?
IX. Sensor Replacement and Cost
I. A Camshaft Position Sensor Can Fail Without Warning
An intermittent or complete CMP sensor failure while on the road could be dangerous. It could happen at any time: You are driving on the highway, moving along in fast traffic, when your engine suddenly loses power. There is nothing to do but watch in horror as a vehicle approaching at 70 miles an hour rear-ends you. Not a pretty picture, but it's happened many times.
Other times the driver becomes aware of a failed CMP sensor when the engine refuses to start.
Here, we'll explore the symptoms of a bad camshaft position sensor and what you can do about it. But let's discuss first what the sensor does.
II. What Is a Camshaft Position Sensor?
Your engine's cylinder head houses one or two camshafts—a shaft equipped with offset lobes—to operate the intake and exhaust valves. The crankshaft, located in the engine block, drives the camshaft using gears, a timing chain, or a timing belt.
To determine which cylinder is in its power stroke, your car's computer monitors the rotating position of the camshaft relative to the crankshaft position using a camshaft position (CMP) sensor. It uses this information to adjust the spark timing and the operation of the fuel injectors. Thus, the CMP sensor affects fuel economy, emissions control, and engine efficiency.
The two most common camshaft sensors you'll see are the magnetic and Hall-effect types. Both transmit a voltage signal to an electronic control module or to the car's computer.
The magnetic type produces its own AC (alternate current) signal (a sine wave), and you can identify it by its two wires. The Hall-effect type uses an external power source to produce a digital signal (a "square wave," on-or-off) and has three wires.
Note: If you are new to all this, you should know that the camshaft position sensor is a different part from the crankshaft position sensor.
III. How the Sensor Can Fail
Just like every part or component in your car, the CMP sensor will eventually stop working when it's reached the end of its service life, because an internal part, wire, or related component has failed. The symptoms your engine may experience at this point can vary, depending on the type of sensor failure: for example, a problem in the circuit, the connector, the sensor itself, or a related component.
Once your car's computer detects a CMP sensor failure, it will trigger the engine light and store a diagnostic trouble code (DTC) in its memory (see the table below for common camshaft position sensor trouble diagnostic codes).
IV. CMP Codes and What They Mean
|Common CMP Trouble Codes||Source of Trouble|
Circuit range or performance problem
Circuit low input
Circuit high input
V. Camshaft Position Sensor Location
As you may expect, the specific location of the camshaft position sensor varies by a vehicle's make and model. On most models you can find the sensor somewhere around the cylinder head. Look around the top section of the timing belt/chain cover (in the front of the engine) or at the rear end of the cylinder head. Some GM models may have a special compartment for the sensor.
Also, some Mercury Villager and Nissan Quest models locate the CMP sensor inside the distributor housing, as well as some Dodge Ram B1500, B2500, and B3500 series models with gasoline engines.
Depending on the specific model of your car, your engine may have one or more cam sensors.
If you need help finding the sensor(s), check the vehicle service manual for your particular model. You may find a copy in the reference section of your local public library. I highly recommend that you buy an aftermarket repair manual for your specific vehicle make and model (Haynes is a good inexpensive brand) for reference when doing maintenance and small repairs.
VI. CMP Sensor Troubleshooting
If your car computer has already triggered the engine light, you may retrieve the code (the DTC) using a code reader or a relatively inexpensive scan tool. If you don't own a code reader and can't afford to buy one, and you still can drive your car safely, just go to a nearby auto parts store that retrieves DTCs for free.
After confirming a CMP-sensor related trouble code, it's worth doing some simple tests. A trouble code pointing to a potential CMP sensor failure doesn't necessarily mean that the sensor itself is bad. You may be dealing with a wire, connector, or related component failure that you can fix yourself.
However, confirming the good or bad operation of a camshaft sensor may require a scope. A failing sensor signal, for example, may be hard to check without special equipment. Still, you can do some simple checks in your garage using a digital multimeter (DMM) tool.
- First, check the condition of the sensor's electrical connector and wires. Unplug the connector and check for rust or contamination, like oil, that is interfering with good electrical contact. Then check for wire damage: broken wires, loose wires, and signs of burns caused by nearby hot surfaces. Also, make sure the sensor wires are not touching spark plug wires or ignition coils, which may interfere with the sensor's signal.
- After these checks, use a digital multimeter that can test either alternate current (AC) voltage or direct current (DC) voltage, depending on your particular type of camshaft position sensor. You'll also need the correct electrical values for your particular type of sensor. You may find this information in your vehicle repair manual.
- With some sensors, you may back-probe the wires through the sensor electrical connector.
- If this isn't possible, see if you can unplug the sensor connector and attach a strand of copper wire to each terminal on the connector. Then plug the connector back in so that the two strands stick out through the connector's housing.
- Another testing solution is to pierce through each wire using a pin, being careful not to short out the wires during your tests. If you use this last method, use electrical tape to cover the pin holes on the wires' insulation after you're done with your tests to prevent corrosion from creeping into the wires.
Testing a Two-Wire Sensor:
- If you have a two-wire, magnetic-type CMP sensor, set your multimeter to "AC volts."
- Have an assistant turn the ignition key on without starting the engine.
- Check for the presence of power flowing through the circuit. Touch one of your probes to ground (any metal part on the engine) and the other probe to each one of the sensor wires. If neither wire has current, there's a failure in the sensor's circuit.
- Have your assistant crank or start the engine.
- Touch one of your meter probes to either one of the sensor wires and the other probe to the other wire. Check your meter display and compare your reading to your manual specifications. In most cases, you'll see a fluctuating signal between 0.3 volts and 1 volt.
- If there's no signal, you have a bad CMP sensor.
Testing a Three-Wire Sensor:
- Once you identify the power, ground, and signal wires using your vehicle repair manual, test the sensor's circuit by setting your multimeter to "DC volts."
- Have an assistant turn the ignition key on, but don't start the engine.
- Touch the black probe on your meter to ground (a metal bracket, bolt, or metal surface on the engine itself) and the other probe to the power wire. Compare your reading to the specification in your manual.
- Have your assistant crank or start the engine.
- Touch the signal wire with the red probe from your meter and the ground wire with the black probe. Compare your reading to the specification in your vehicle repair manual. If the voltage signal is lower than the specification, or no signal comes out of the sensor, most likely the sensor is bad.
- Remove the sensor and inspect it for signs of physical damage or contamination.
Check the video below to see how you can perform these tests using a test light and a multimeter. It'll give you an idea of the nature of the tests too.
VII. Video: Testing a Camshaft Position Sensor
VIII. What If My CMP Sensor Seems to Be Working Fine?
If it seems your CMP sensor is working correctly, consider these possibilities.
Fuel injectors not firing:
In many vehicle models, the car computer uses the CMP sensor signal to fire the fuel injectors.
If you've determined that your engine has spark but fuel injectors are not firing, there's a chance your CMP sensor has failed.
CMP Sensor internal circuit malfunction:
It's not uncommon for a CMP sensor internal circuitry to develop an electrical open. This is usually caused by the sensor being exposed to engine high operating temperatures.
High temperatures can break a wire. The broken wire may still make contact while the engine is cool. As soon as the engine compartment temperature increases, the damaged wire may expand and separate, creating an intermittent failure.
Faulty timing belt or chain:
If your tests seem inconclusive, especially if the problem has triggered a CMP sensor related trouble code, you may want to check your timing belt or chain.
Timing belts (not so much timing chains) will stretch after miles of hard work, and tensioners will wear out over time, upsetting spark timing.
This will not only show the symptoms of a bad camshaft sensor but even trigger a CMP sensor related trouble code.
Some car manufacturers suggest replacing a timing belt and tensioner every five years for this reason.
If necessary, consult the vehicle repair manual for your particular vehicle make and model.
IX. Sensor Replacement and Cost
If you've confirmed that the camshaft position sensor is bad, you may want to replace it yourself. On some vehicle models, replacing the sensor is just as easy as unplugging the electrical connector, unscrewing the mounting bolt, pulling the sensor out, and installing a new one. On other models you may need to remove one or more components to gain access to the sensor (as you will see in the next video).
Check your car's repair manual for instructions on how to replace the sensor on your particular vehicle model.
Expect to spend anywhere between $30 and $100 (or more) for the sensor itself, depending on your vehicle model. If you take your vehicle to a car shop, you may be looking at $100 or more in labor expenses too.
The symptoms I discussed above are not clear signs that your CMP sensor is bad. Still, if you recognize one or more of these symptoms, try to diagnose the problem as soon as possible. The last thing you want is to get stuck in the middle of the road. Start by getting the trouble codes from your computer memory, and, if necessary, testing the sensor with the help of your vehicle service manual. Sometimes you can determine the cause of the problem and fix it yourself without spending too much time and money.
Test Your Knowledge
For each question, choose the best answer. The answer key is below.
- Which of these conditions may be caused by a bad camshaft position sensor?
- Missing during acceleration
- Coil failure
- Short spark plug life
- No spark
- Which of these engine operating conditions can harm the camshaft position sensor?
- Worn-out engine oil
- High temperature
- Overstretched timing belt
- Cylinder misfire
- Which of these important devices could be disabled by a bad CMP sensor?
- starter motor
- radiator fan
- fuel pump
- timing belt
- No spark
- High temperature
- fuel pump
This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.
Questions & Answers
Question: Can a faulty camshaft sensor cause a knocking sound?
Answer: No, a faulty camshaft sensor can't cause a knocking sound unless it affects ignition timing.
Question: What is code P0340 on my Camshaft Position Sensor?
Answer: The code points to a fault in the camshaft position sensor circuit.
Question: Will a bad camshaft position sensor cause a car not to crank over?
Answer: Normally it won't prevent current from reaching the starter, but it may 'disable' the ignition system - no spark.
Question: I just replaced the camshaft 2 months ago. Why is it bad again?
Answer: Contamination from oil, moister or oil, vibration, can cause a camshaft sensor to fail prematurely. Check the mounting area for signs of contamination and make sure the unit is properly secure. Also, check for wiring damage. This may also cause a bad effect on the sensor itself.
Question: Can a car's camshaft go out if you were hit?
Answer: If it was a hard hit and it caused the sprocket to misalign, it can probably affect the sensor.
Question: What will happen if I confuse the camshaft and crankshaft, thus accidentally trying to start the car with a camshaft sensor where the crankshaft sensor should be?
Answer: I've never done it myself, but both sensors measure speed and position of internal engine components. I would assume within the same application the physical configuration of each sensor is different to avoid mounting the sensor in the wrong place.
Question: Would a bad camshaft sensor cause only one cylinder to misfire? The coil plug and injector have all been replaced on my 2004 Jeep Liberty 3.7.
Answer: The computer uses the camshaft sensor to detect cylinder power stroke, using its relative position to the crankshaft. If there's a problem with the signal plate, it's possible to have a misfire in one cylinder. Usually, on these models, the ECM will disable that particular cylinder to prevent raw fuel from going to the cat.
Question: Could code PO206 be CMP related?
Answer: Not really. This usually refers to a fuel injector or its circuit. The CMP looks at the rotation of the camshaft regardless of fuel injector activity.
Question: I have code PO340 The engine starts and runs fine, "but has extended starter turn over. " Meaning the starter will seem to turn the engine over at least two cycles before it starts. What could be the problem?
Answer: The problem could be with the sensor itself or the circuit. The signal is not properly reaching the computer.
Question: Will a faulty camshaft sensor cause an evap code to also occur?
Answer: No. The camshaft sensor work with the crankshaft sensor to monitor cylinder 1 compression stroke. The evaporative emissions system controls fuel tank vapors.
Question: Where is the camshaft position sensor located on my 2001 Mitsubishi Challenger?
Answer: This guide may help you. It's the Montero, but I believe is the same engine.
Question: What does code P0303 mean related to a camshaft position sensor?
Answer: The computer has detected a cylinder three misfire. This is usually a problem in the ignition system for that cylinder, or sometimes an intake leak affecting that cylinder.
Question: I found metal shavings on one of the camshaft position sensors. Does this mean the motor is junk?
Answer: It’s ‘normal’ for camshaft and crankshafts to collect some filings. The magnets pick this up. It’s part of the normal wear and tear, although sometimes this indicate damaged metal parts.
Question: How can I find and change the cam sensor on a 2002 Dodge Ram V8 engine?
Answer: I believe the sensor is located on the timing cover, next to the engine control module (ECM). It has a single mounting bolt and an electrical connector.
Question: Can a faulty camshaft sensor cause a P0300 code?
Answer: A number of faulty components may trigger a P0300 code, including:
a bad camshaft position sensor
bad spark plugs or wires
problems with an exhaust valve
bad fuel injector
bad ignition coil
bad oxygen sensor
blocked or inoperative EGR valve
Question: Can a faulty cam sensor cause a catalytic converter to get red hot?
Answer: If the faulty cam sensor has a bad effect on ignition timing (at least in some models), it can lead to a misfire; enough raw fuel will cause the catalytic to get red hot.
Question: Can a faulty camshaft sensor cause a hard shift in an automatic transmission?
Answer: Yes, a faulty camshaft position sensor can cause hard shifting or lock a gear in place.
Question: When I start on a cold engine everything is fine, but after a minute the engine begins to cough, and there is a malfunction on the camshaft sensor. What could be the issue?
Answer: Check the engine temperature sensor first, and then test the camshaft before changing anything.
Question: What do I do when my car won’t start due to a bad cam sensor?
Answer: Troubleshoot the sensor first to make sure that's the problem - there could be problems with the circuit as well. You may need the vehicle repair manual for this.
Question: Can bad oil cause a cam sensor fail?
Answer: The more like sources of failure is the sensor itself, a problem in the circuit or the PCM.
Question: If the sensor is bad, can the spark be functioning and the injectors not pulse?
Answer: camshaft references compression or exhaust stroke, but a crankshaft position sensor is more likely to affect pulse.
Question: What would cause my car to quit while driving? It will only start if you turn off the key and then it starts.
Answer: There could be several causes, restricted fuel filter or problems in the fuel system (check for pressure), bad fuel pump, vacuum leak, or a bad sensor. Check for trouble codes, even if the engine light is not on. There could be a pending code.
Question: I had the camshaft position sensor replaced for the first time in March. The truck did OK until August. Then it would cut off and hard start, code P0345. I replaced the same sensor in August. Now its November and showing the same symptoms. The car is a 05 Frontier. Also, the SLIP trouble light comes on but goes out when the sensor is replaced. What can cause three sensors to fail in 8 months?
Answer: For some reason, the computer is detecting that the Stability control system is not operating. But the problem might actually be in one of the main systems, and this could be affecting the camshaft position sensor, possibly the sensor’s circuit. Check the connector and related wires. There could be a problem.
Question: What would happen if only one camshaft sensor does not work but the other one works?
Answer: In some models, the engine may still work with one sensor without starting problem if the computer uses the crankshaft signal to figure camshaft position.
Question: can a faulty Camsensor cause the car to not spark at all?
Answer: Yes, it's possible the ignition system can fail.
Question: Can the camshaft sensors go out without the check engine light coming on?
Answer: Usually, if the sensor starts wearing out, the computer may not turn on the check engine light, or if the fault is intermittent. But once the PCM detects a problem with the sensor or the circuit, the engine light will come on.
Question: What does P0335 code coming from my vehicle mean?
Answer: The P0335 code usually refers to a possible failure of the crankshaft position sensor or the circuit (damage connector or wries). But the fault can also be with the reluctor ring or, less likely, the car computer.
Question: My car has a 345 code. What is that?
Answer: The code points to a problem with the camshaft position sensor - bank 2. A worn voltage reading. Inspect the sensor for contamination, also the wires, or a bad sensor.
Question: My 2011 Altima is letting out white smoke and is needing oil depending on how much miles I run it. Now, the computer just came up with the camshaft position sensor. Is that sensor whys it's doing that?
Answer: The CAM tells the computer the position of the camshaft, and works in sync with the crankshaft sensor, so the computer knows when to fire an injector (depending on model) and to fire spark. The white smoke is more related to coolant or oil leaks (bluish smoke) into the combustion chamber. So most likely there's a leak at the cylinder wall, rings, valve or head gasket. You may need a compression test and leak down test to diagnose the problem.
Question: Can a bad CMP cause engine light to come on?
Answer: Yes. Either a circuit or sensor signal problem can throw a P0340 – P0344 trouble code.
Question: What is a Code 0341?
Answer: This usually points to the cam sensor circuit, but it could also be a sensor problem. A loose wire or bad connection (at the sensor or PCM), a bad sensor, or a sensor that has difficulty "reading" the reluctor wheel is possible.
Question: Can a faulty camshaft sensor cause engine to overheat?
Answer: No, but this post might help:
Question: Can a sensor act this bad? I have a Nissan Sentra 2005, and after the car becomes hot; anywhere from 15 minutes to 3 hours, I have to crank it at least twice before it starts. I have replaced the crank sensor, but no change. I replaced the cam sensor four times from different suppliers, and the car won't start hot or cold. So I put the original sensor back in, and it starts. Yet I still have the same issue for that 2 to 3 hours when it's hot
Answer: Some models will not function properly unless you use OEM. Get the DTCs and go from there. You may need to check the circuit as well.
Question: Can a faulty camshaft sensor not show a code?
Answer: Usually a camshaft sensor intermittent failure can produce no code. But you'll notice a change in driveability performance at times.
Sometimes it's possible to detect the failure with a scan tool.
Question: I have a P0320 error code, and I replaced both the camshaft and crankshaft sensors. What could be the problem?
Answer: The problem is more likely to be in the circuit, between one of the sensors and the computer (power or ground), a short. Check the connectors (possibly a poor connection) and wiring (loose, damaged or corroded). Less likely, a problem with the computer.
You may need a digital multimeter to check for an incoming reference signal for the sensor(s). This other post can help you check the crank and camshaft sensors. You’ll probably need the wiring diagram to identify the wires and the specs for your model. You can find the diagram in the vehicle repair manual for your model.
Question: My car has lost power and backfires after I shift and surges while driving. What could the problem be?
Answer: It could be a timing issue, but make sure there are no problems in the valve train. Are all the valves working fine? See if you can remove the valve cover and check the valves at idle and see if something doesn't look right. Press the rocker arms with your thumb on each. See if something changes.
Question: How long can I go with a bad camshaft sensor. It happened on 1/25/18. I can only go to 60 miles per hour normal speed and won’t let me go further than that?
Answer: That depends on your particular vehicle make and model. If the sensor actually has failed, you are doing more damage to the engine and you could end up with an expensive repair later on. It's much cheaper to replace it.
Question: My car gets spark and fuel, but still, no start. Can a bad cam sensor cause the no start? I ran a scan which read as a bad sensor.
Answer: On some models, a bad sensor can prevent your car from starting. Check the sensor. Consult your vehicle repair manual for your model for this.
Question: Can a faulty camshaft sensor cause unexpected acceleration while the brake is being applied?
Answer: Besides human error, unintended acceleration usually is caused by a mechanical malfunction in the accelerator assembly (check if something is interfering with the linkage going to the throttle body) -- or from an electrical system malfunction in the cruise control system (sometimes a bad throttle position sensor) or the computer. Haven't heard of a bad camshaft position sensor causing this, though.
Question: I have a 2009 Mini Cooper S that died on the road and will not start. It has the code 2983 Intake Cam sensor and I have replaced it twice. I also replaced the Vanos Solenoid and it still won't start. And the code keeps coming back. Any ideas of what I should do?
Answer: The problem could be in the connector or the wires in the harness. Check the connector for corrosion or buildup, and make sure the wires are not loose. Carefully tug the wires and make sure they are tight and properly connected.
Question: Is repeated failure and replacement of a sensor a symptom of another problem?
Answer: If the same sensor is failing, the problem could be in the circuit. You may want to check the wiring diagram for your particular model. Use your vehicle repair manual. if you don't have the manual, check the reference section of your local library. Possibly you can use a test light or digital multimeter, depending on the circuit you are testing.
Question: Would a faulty cam sensor get worse over time? What are the symptoms over six months?
Answer: On some models you may notice first problems staring the vehicle, then you’ll notice problems while accelerating or at idle (hesitation, stumbling), until the sensor is gone.
Question: I installed a new distributor 5 months ago and I had a miss immediately. I thought It was maybe a bad plug. Now it either won't start for long periods and shuts off real frequently during idle and while driving. Now I hear it's probably a bad COS and it's located in the distributor as unserviceable part. I don't know how to check it and costly to replace. Could the COS be bad and what is your advice?
Answer: You may need to check the ignition system to trace the fault. Most likely the vehicle repair manual for your model will tell you what tests you can do. If you don't have the manual, check the reference section of your local public library for it.
Question: Can a faulty camshaft sensor make my transmission stop working?
Answer: It is possible in models where sensors share data for the transmission as well. But check the sensor before replacing it.
Question: Can a faulty camshaft position sensor cause smoke to come out of your exhaust?
Answer: It is possible for a bad cam sensor to cause black smoke. Other possibilities are the MAF and MAP sensors and bad fuel injectors.
Question: Can a P0335 code be caused by a bad timing chain?
Answer: It's possible, but it's usually more likely to be a fault with a crankshaft position sensor or circuit.
Question: Why does the top metal part of my sensor have wear on it like something is scraping it?
Answer: High temperature and vibration may have a "wearing" effect on the sensor's material.
Question: Can a faulty camshaft sensor stop fuel delivery?
Answer: A faulty sensor may interfere with the ignition and fuel system. The signal is used by the computer to fire the spark and operate the injectors.
Question: I have a 06 Dodge Dakota. It has a bad misfire change. The coils and plugs are still the same. What is this?
Answer: This post might help you:
Question: If the camshaft sensor is bad, do you have to change the crankshaft at the same time?
Answer: Not necessarily. If the crankshaft sensor is working, just replace the camshaft sensor.
© 2015 Dan Ferrell
Dan Ferrell (author) on September 02, 2020:
It doesn't seem like they have taken care of the problem if the check engine light is still on. If there's another problem with the engine or transmission, they should let you know and explain exactly what's going on. if they are just asking for more money, I think you should go to a consumer protection agency in your city and present a complaint. Hope this help.
Mukesh Pandya on September 02, 2020:
I visited Meineke on 05/16/2020, I was given memo to take care of Crank Shaft position sensor as my car dashboard showing service engine soon ,coolant was low and power steering fluid may have leak. I took care of Coolant and power steering fluid. I went to anther merchant Robert Auto on 06/12/2020, I gave him a copy of Meineke's Memo so he can know what need to be done ( service engine sign to take care). First i was asked to pay $160. when i went to pick up a car on 06/15/2020 after test driving i showed him till service engine soon light is on . He took car back and after 3/4 times test drive i was asked to pay $332.04 . I paid money what ever i was asked to pay but till date it showing sign of engine service soon on my car dashboard. I have a very limited knowledge of car or computer being a senior of 74 years of age .
My question and concern would be even after paying $332.04 if my problem not solved and still showing service engine soon sign . What should i do? I visited him and explain by showing sign not taken care of but now he is asking more money for try and error. Do you think Robert Auto did his job ? He took care of Crank shaft position sensor? For what i paid $332.04 not taken care of dashboard sign of service engine soon.
It's just like a doctor who perform different surgery and tell patient that if you are concern or not but i did my job. I would appreciate if you would help me by answering my query that how I can justify that after paying $332.04 my car showing sign of service engine soon ? My service not done and i lost my money. .
Expecting your early reply.
Dan Ferrell (author) on July 20, 2020:
A bad CMP sensor may interfere with the ignition system, which may lead to this symptom. You can test the sensor before replacing it. Download trouble codes and see what you find. There could be other problems. Hope this helps.
John on July 20, 2020:
Will a bad camshaft sensor keep the fuel pump from working i just put new fuel pump in it took awhile to work but finally started working and was fine then one day just quit again
Dan Ferrell (author) on May 27, 2020:
The CMP in a vehicle can face high temperatures, which can affect a magnet. But it's better to test the sensor itself to know if it's still operating within range. Hope this helps.
Don on May 22, 2020:
Can a bad cmp, determine the strong magnet or low?
Dan Ferrell (author) on May 07, 2020:
Check for trouble codes, even if the engine light is not on. There could be a pending code that can guide you. Misfires may happen for different reasons. A faulty fuel pump or pressure regulator, stuck-open EGR valve may also lead to a misfire. This other post may help:
Kelsey J Lucas on May 06, 2020:
I have a 2005 6 speed Acura TL, Having problems with misfiring
I have changed the coil packs, spark plugs, and all the fuel injectors.
it has a huge slag in acceleration and has a hard start. What could the problem be? my friend thinks is the Cam shaft position sensor but after spending so much money on parts just trying to make sure im fixing the right thing this time
Dan Ferrell (author) on March 18, 2020:
Make sure the ignition timing is correct. A scan tool would let you know if the ECM is actually receiving the signal from the sensors. Also, the VVT system is very delicate, specially when it comes to dirty oil. A leak would warrant a careful look at the system. Hope this helps.
Niccolson on March 17, 2020:
I got a fault code p0341-11 cylinder 1 camshaft sensor missing signal on my Proton Persona Elegance 1.6L.
Camshaft Position sensor
Top Overhaul due to the engine oil leaks
Hardness Wire (Engine) Checked Good
So, i need some advice or ideas what to do next. Hopefully you can help me out of this issue. God Bless
Dan Ferrell (author) on March 07, 2020:
On some models a faulty CMP can lock the transmission. Usually, a slipping transmission is caused by faulty bands, oil (automatic) or a worn clutch (manual). If you have a manual transmission, this other post may help diagnose the issue:
Dan Ferrell (author) on March 04, 2020:
The code's description points to an over advanced camshaft (bank 1 where cylinder number 1 is located) compared to the computer's programmed specifications. The most common reason is dirty oil or low level. But the problem could be with the camshaft actuator, its circuit or, sometimes, the timing chain.
The loud exhaust sound could be from a gasket leak or damages component in the system.
Have the actuator tested first. If it is bad, you can replace it.
This video may help:
Nicole on March 03, 2020:
I have a Chevy equinox 2017 LT and I have code p0014 what could this be and will it be expensive also my exhaust sounds very loud like a diesel truck, could this be related?
Dan Ferrell (author) on February 18, 2020:
Models with a variable valve timing (VVT) systems are overly sensitive to engine oil condition (dirt, foreing particles and such) and oil flow restrictions. This is usually the context where both codes would appear. This could be just a perforance issue, requiring an oil change or something more serious affecting the VVT system, a faulty camshaft sensor or timing issue. I'd replace the oil more frequently to 3000 miles or so, specially a turbo model. If the code reappears, I'll start looking into the sensor and timing issues. Hope this helps.
Bdub46@msn.com on February 18, 2020:
What on a 2005 subaru Forrester turbo can cause both a p0011 and a p0021 error message for the CMP's.
Dan Ferrell (author) on November 25, 2019:
The sensor shouldn't move from its mounting position, otherwise it won't be able to produce the signal. Check the mounting bolt and secure it in place. If necessary, consult the repair manual for your particular vehicle model.
MASOUD on November 24, 2019:
Camshaft Position Sensor in nissan almera does not work perfectly in its exact place but when i move it like a half circle it is working and the engine can start ? could i know the problem of that
Dan Ferrell (author) on November 15, 2019:
A crankshaft sensor and other can cause the same symptoms. Try downloading trouble codes, even if the engine light is not on. There could be a pending code that can help you. This other post may help too:
Junior on November 15, 2019:
I have 2011 Audi A5 , one day just died they told me fuel regulator need to be replaced I did replaced along with fuel pump and still doing the same think, what can possibly be?
Dan Ferrell (author) on October 25, 2019:
If the engine turns over, it is cranking. Check compression; make sure you got good fuel pressure and spark. Downlaod trouble codes, even if you don't see the check engine light on. There could be pending codes. If the engine doesn't turn over, check the starting system. Hope this helps.
Anthony Gaines on October 25, 2019:
I bought a 2004 Dodge Ram 1500 5.7 hemi SLT from my co-worker. She said that the truck just cut off on her and never crank again. I put new plugs,wires,and a new computer module. No luck, all she was the same thing,turning over. Just wont crank, i have even had backfires. Fuel pump is good. I just order this sensor. Pray this fix the problem. What do you have offer?
Dan Ferrell (author) on September 17, 2019:
The problem could be in the fuel system or oil may be leaking into the cylinders. Check the fuel pressure for that cylinder. You may want to check compression on the same cylinder. Hope it helps.
Ketcho on September 17, 2019:
I have a 1999 Ford F150 4.2L. Misfires at about 20 to 30 I replaced the oxygen sensors. No change. Replaced fuel pressure regulator no change. Replaced major vacuum hoses. At full RPM misses a lot. checked the coil, spark plug wires, which I replaced about a month ago. If I did the tests right everything is good. I also regapped the plugs as several were sutted. I since checked them again only one had a lot of sut on them. The ceramic cone on most was clean and white. Still no change. However not when I start it, it seem to back fire and seems to lock up monteraly but then continues to crank and starts.
Dan Ferrell (author) on August 20, 2019:
This video may help:
Michael johnson on August 19, 2019:
How do I replace a cam senser in 1990 Chevy 2500 truck
Dan Ferrell (author) on August 02, 2019:
Problems with the tensioner or support rail usually translate into a rattle and/or clicking sound coming from the timing chain. It's possible that it can cause the camshaft sensor to produce a false signal since the crankshaft and camshaft won't be synchronized. This seems to be a problem in some Mini Cooper models. But you may want to get a second opinion to make sure you are making the correct repair for your model. Hope this helps.
Anthony on August 01, 2019:
Got a 2003 mini cooper S replaced the camshaft sensor twice was told that it's the timing chain tensioner is that Possible
Dan Ferrell (author) on April 06, 2019:
There could be several possibilities; the problem seems to be temperature related. The problem could be with a sensor, but also make sure there’s enough fuel pressure when the car is at operating temperature. This could be a worn fuel pump issue. The coil seems to fail after the unit warms up. Also, check the engine grounds:
If necessary, have the ignition system checked as well.
moe11032 on April 05, 2019:
So I have this 2008 Nissan Altima v6, the car drives fine and starts fine when the engine is cold. when the engine is hot and when I accelerate hard it shuts off completely or it gets down on power and warning lights pop up ( CEL, battery, slip,TCS,ABS, handbrake), when I disconnect the positive lead on the battery and reconnect it, the car restarts and only then I can drive it slowly or else it will shut off again. the problem doesn't appear to happen when the engine is cooled. I connected an OBD before/during and after the problem but no codes are recordable. I have a suspicion on either the cam shaft position sensor or one of its wiring. I'm not really sure on this but need some guidance.
Dan Ferrell (author) on March 30, 2019:
There could be a problem in the connector itself (loose or damage wires) or the circuit itself. Check the signals and reference voltage.
Ivet on March 30, 2019:
I have put in new map camshaft and crackshaft hhr2097 still get code and a small jerk while driveing
Dan Ferrell (author) on March 20, 2019:
The problem may be in the cam sensor circuit. The ECU is detecting a bad or distorted signal. Download the trouble codes again and see if there are more stored in memory. Use that as guide and check the cam's circuit.
Val on March 20, 2019:
I had code P0349 and was told to replace camshaft sensor. We replaced it car did fine for a bit and then engine light came on. And when you go to take off around 30 -40 miles and hour all the lights on the dashboard flash red and then it stops. Any suggestions?
Dan Ferrell (author) on March 18, 2019:
Check the circuit. Many times the problem is not with the sensor itself, but the connector or the wiring. Make sure to read the description of the trouble code. There could be other things triggering the code.
Shauna sheely on March 16, 2019:
I have a 2010 Infiniti g37 base and when i got the car it started to jerk and the check engine light come on for the driver side cam shaft sensor so i replaced it and the speed picked up and all but then the same thing and code came back on so i tried the other side and my car wouldnt start with the new one so i ordered another one and same thing happened but when u put the old one back on it pick up speed the check engine light go out for 10 minutes and then it starts the jerking again i dont no what to do!
Dan Ferrell (author) on February 19, 2019:
Make sure to scan for trouble codes even if the check engine light is not ON. Also, this other post can give you some ideas where to look, if necessary:
Charlie on February 19, 2019:
I have a 2001 ford f150 with a 4.2 v6 . it getting gas and spark but wont start. I changed the cam and crank shaft sensor but still wont start. What could it be.
Dan Ferrell (author) on February 13, 2019:
Scan for trouble codes, even if the engine light is not on. The engine might be in ‘limp’ mode from the ECU to prevent damage. If this is a transmission problem, the could be several reasons for this: clutch adjustment problem, clutch linkage or shift rail binding, or internal issues. Hope this helps.
Brian S on February 13, 2019:
I have a 2005 Maxima and it hard shifts when changing gear, it dies randomly and won't go over 35 mph
teklemedhin on February 06, 2019:
i say thank you thank you i learn more i apreciate thank you
Dan Ferrell (author) on February 04, 2019:
It is possible, but there are several components that can cause a misfire including a stuck open EGR valve, a vacuum leak, PCV valve issues. This other post can give you an idea on misfires:
However, you might want to scan the computer for trouble codes, even if the check engine light is not coming on. There could be some pending codes that can help you in the diagnostic.
If you have the vehicle repair manual for your model, it can save you some time as well.
This other post can help you test the ignition coil, if necessary:
Frankie Uptain on February 04, 2019:
I have changed Crank shaft sensor, plugs and wires and distributor cap and fuel filter,not missing as bad,could it be the coil?94 Nissan Altima 4 cylinder
Dan Ferrell (author) on January 07, 2019:
The CAM tells the computer which cylinder is in the power stroke. But a bad sensor can prevent your engine from starting (on some models). It won't drain your battery.
Ieisha on January 07, 2019:
Would a CAM cause the battery to drain completely?
Dan Ferrell (author) on December 15, 2018:
Usually the best way to go about trouble codes is to check the components indicated by the code. Sometimes an apparently unrelated component can trick the computer into 'thinking' that another sensor is bad. May be this post can help you wtih the camshaft sensor:
abedl on December 15, 2018:
I have honda civic 2001 had connected to obd 2foult camshaft sensor so another foult fuel system which one to replace
Dan Ferrell (author) on November 15, 2018:
You might want to check the circuit (wiring and connector) to the sensor and the crankshaft position sensor. Also, there could be a problem with the gear. Since there was possibly a knocking, check the ignition timing as well.
Brian H Chan from Las Vegas, NV on November 15, 2018:
My Infiniti G37 2013 camshafts Position sensor went out while driving. Lucky not a lot of traffic.
I replaced the sensor and my battery(possible was being drained by faulty the sensor) Issue now is that I’m not getting ignition. When I try to start it sounds like the starter tries to but no acutual combustion happens.
I did a reset on the ecu I believe. Where you had to press pedal 5 times wait however long and what not. I think that’s called a soft reset. After I did that, I tried starting again. Still the same but the second time it sound like I got a quick 1 sec combustion that’s it.
Then I cleaned my throttle body and mass airflow sensors because I was at a loss praying the valve is not opening. But the valves are good. Still no luck.
Before all of this there was a few times that I had to get a jump randomly. I had to also change my spark plugs because of some knocking. The spark plug on cylinder 1 had a bunch of black gunk. Then a few weeks after I had an empty tank of gas so I decided to use one of those cleaners you add with a full tank. That cause the new spark plug on cylinder 1 to get gunked up again. So I changed that spark plug again. Each time I would clean the throttle body and mass airflow since I had to take those off to access the sparks plus. That’s when after a few weeks is the camshafts position sensor went out with a code.
Dan Ferrell (author) on October 30, 2018:
First check for DTCs, even if the engine light is not coming on. There may be a pending code that can point you in the right direction. If there are no DTCs but the engine cranks and doesn't start, you may want to check the ignition or fuel systems, intake air system, or restrictions to the exhaust system. These are the usual suspects.
Lipton Tilfas on October 29, 2018:
I have a 2001 Nissan X Trail and it fails to start. I am planning to buy a new crankshaft position sensor to replace the existing one. Do you think the camshaft position sensor is the cause of the problem?
Dan Ferrell (author) on October 02, 2018:
Check for potential DTCs - this usually happens with a bad sensor that affects a lean or rich fuel mixture (temperature sensor, throttle posistion sensor, oxygen sensor). You can see this happens with bad connected or loose wires on some of this sensors (ignition or fuel system). If there are no DTCs, check the air filter, spark and fuel pressure, and MAF sensor. Hope this helps.
kimcoons on October 01, 2018:
I have a 2009 traverse and it seems like its not getting gas, at a low speed it stumbles so could it be the camshaft position sensor?
Dan Ferrell (author) on October 01, 2018:
Sometimes this happens because of a bad battery. You might want to check the battery and the sensor as well. And take it from there.
Ankur on September 30, 2018:
Hi i have a BMW 320i-2008 model. The car cranks and does not start, the error code is A3AD &A3AE. We have tried everything and finally the mechanic says it is the crankshaft sensor, however there is no engineer no engine light on.please help
Dan Ferrell (author) on September 28, 2018:
Make sure you've replaced the fuel filter, check the pump relay. Make sure theres voltage getting to the pump and check fuel pressure with a gauge. This post may help:
Anthony Cox on September 28, 2018:
My 02 Tahoe LS is not getting any fuel to the fuel rail and I have changed the fuel pump with a Carter fuel pump and also changed the FPR and still no gas when I mash the valve. What could be the reason?
Dan Ferrell (author) on September 01, 2018:
You need to clear out the trouble codes from the computer memory. This causes the engine to run poorly because the computer re-calibrates to optimize engine performance.
Hope this helps.
Richard Jaime on September 01, 2018:
I have a 2010 Challenger. Had the camshaft sensor replaced. Is the computer supposed to be reprogrammed? Hearing different story from different dealers. Help, please.
Dan Ferrell (author) on August 08, 2018:
This video may help you find it.
Anita on August 08, 2018:
Where IS MY crank shaft positioning sensor on 2001 pathfinder
Dan Ferrell (author) on August 04, 2018:
There could be some mechanical damage. You need a diagnostic form a shop. Check the starter motor, make sure it's correctly installed. You may need to pull it out and see if it's still in good condition. An auto parts store may check it for free.
Fred on August 03, 2018:
Sir,my car is having issues, my bottom plate bust on my engine oil pour out totally.trying to manage the vehicle to machanic I was told my metal was already bad we change the metal, fixed up the car but now am experiencing problem of sudden breakdown of the vehicle when moving...Also I hear cracking noise when I try to fire the vehicle
Dan Ferrell (author) on July 25, 2018:
In general, the camshaft sensor works with the crankshaft sensor to send information to the ECU,(car computer), to synchronize some operations of the fuel injection system and knocking control. A bad camshaft may also affect spark.
The camshaft sensor may failed due to mechanical damage, failing to 'read' the enconder wheel (bad wheel-tooth?), electical circuit malfunciton of the sensor.
Hope this helps.
Amarjit on July 25, 2018:
When I drive suddenly car engine of and try start not starting fuel, plug, crank sensor is working but camft sensor not working because of iwant to kwow that camft sensor is bad engine start not working this my question
Dan Ferrell (author) on May 18, 2018:
The code points to a problem with the camshaft circuit. There could be an actual problem with the circuit or the computer. Usually, a problem with the circuit will manifest as drivability probems - loss of power, misifres, and - depenidng on model - hard to start issues. Either way, its a good a idea to take a look into it.
Sarah on May 18, 2018:
My 2005 dodge neon check engine light came on a couple days ago and when I checked the code it was P0340. I haven't had any issues driving or felt anything different. Could the code just need to be cleared, or is there really something wrong?
Dan Ferrell (author) on April 26, 2018:
It is possible a faulty camshaft can cause a misfire. Other common possibilities are a dirty or bad fuel injectors, faulty oxygen sensor, an ignition coil, and a faulty EGR valve or clogged passages. If you have an old model, you also want to consider a clogging cat converter and burned exhaust valves.
Yep on April 26, 2018:
Got a p0300 code could a failing crank shaft sensor be the problem,already replaced the vac lines,cleaned intake manifold,idle sensors,spark plugs,tune up
Dan Ferrell (author) on April 24, 2018:
It's possible the first time when the head gasket was replaced there were other damaged that wasn't diagnosed, hence the subsequent loosing of power and stalling - (compression loss?) - You need to have a mechanical condition diagnostic from another shop, if you are still going to the same one - just to see their opinion on the repairs that were done the first time - (incomplete? ) - what caused the cam lobes to burn.
Margarette Groenewald on April 24, 2018:
My Defender 90 had head gasket failure in June 2017, which was replaced. Since then the car started loosing power, loss of engine power and stall intermittently. In Nov 2017 diagnostic test was done after engine failure on highway, filters was changed, fuel system was checked and cleared, ignition key was changed and, car was also fully checked for the long road, In March 2018 replaced engine oil etc, , Filters etc, looked at engine surging & poor idle and replaced housing fuel filter assy. April 2018 hear vibrating noice, car looses power and knocking noise. Just been informed that there is damage to the exhaust cam lobes, 3 lobes burnt. Any views on this please
Dan Ferrell (author) on April 23, 2018:
Check the connectors and wiring for corrosion or damage. Also, some models will only take OEM components and will refuse to work otherwise.
Jason on April 23, 2018:
Just wondering what would be the reasoning if you put a new sensor in and the car still doesn't work and the OBD reader still reads the same thing saying that the sensors not working please help
Dan Ferrell (author) on April 18, 2018:
It's possible there is a problem with the ignition module or even the crank sensor. Scan for codes first, if there aren't any, have the ignition module checked.
Mark Brandenburg on April 18, 2018:
I have a 99 Chevy Silverado with 5.3 engine, when the engine is cold it cranks easy (when I first crank it in the morning) but when the engine is hot or I've driven it for a while and turn off the engine and let it sit for a while then try to crank it again it is hard to crank, so far it has always started back up. I put a new fuel pump on it and timing sensor but it didn't help. What do you think I need to do next?
Dan Ferrell (author) on March 26, 2018:
It's is possible. Read the trouble codes from the ECM for pending codes if necessary, and test the sensor.
Dan Ferrell (author) on March 16, 2018:
Have you checked for carbon buildup in the throttle body-valve, and blocked passages for the IAC?. A vacuum leak is another possibility.
steven meekins on March 15, 2018:
I have a 1995 buick lesabre 3800 engine OBD1 with an OBD-2 connector scan port and can't read engine code...idles too high when cold, too low and intermittent stall when hot, replaced crank sensor, idle motor,TPS, cleaned MAF, good fuel pressure and vacuum....ready to try MAP sensor and cam shaft position sensors...any thoughts..? firstname.lastname@example.org to any who have conquered this before. Thanks.
Dan Ferrell (author) on March 14, 2018:
Hi John q
It is possible you have a failing battery, have it checked and check the connections at the starter for corrosion. A failing starter can do this as well sometime when hot - coil may have cracked. It'll work fine when cold but will struggle when hot.
john q on March 14, 2018:
hard starting when engine warm,honda civic 2.
when this happens occasionally eml and showing code P0339, crankshaft sensor which i have replaced, but problem persists.
Could problem be due to weak battery?
Dan Ferrell (author) on March 05, 2018:
It could be a bad sensor or bad connection.
Also, check for DTCs or pending codes.
Johnny Mora on March 04, 2018:
Hi, I have a Nissan Altima 07' 3.5 My temp Gauge fluctuates goes all the way up on incline while on the road. Then temp goes normal on decline but temperature gauge reads hot on long drives. I've changed the Radiator, Thermostat & still does the same...I did research says maybe a thermo sensor?
Dan Ferrell (author) on February 26, 2018:
My first guess would be a bad connections at the exhaust.
Darrell crum on February 25, 2018:
what will make a 5.7 Vortec engine labor like a diesel
Dan Ferrell (author) on February 22, 2018:
Intermitent faults are hard to diagnose, but the code is pointing to a faulty crankshaft position sensor or circuit. Still, it's a good idea to pull the sensor and check for shavings or other contamination that might be interrupting sensor operation. Also check the reluctor wheel
James on February 21, 2018:
i have a Mercedes e300 w211 272 engine 2008 model. I had a fine drive all day since morning but at some point the check engine appeared and upon parking the car refused to start the engine at the evening while leaving office in the evening. The next day the car started fine and upon taking it for diagnosis the error code p0336 had registered.
it now three days and the car has no issues.
kindly advise on the possible cause of car failure.
Dan Ferrell (author) on January 31, 2018:
You might want to check oil pressure. On some models the computer will prevent you from starting the engine when oil pressure drops below a certain threshold.
Nikita Hirsch on January 31, 2018:
hi i have a 2006 dodge stratus i drove around fine all days but when i came home it stalled i tried starting it back up it wouldnt no engine light came on but odd enough the oil light came on but i got an oil in less then a month it does idle low i live in minnesota so it really cold right now just not sure what to check cause i dont want to fry my starter
Dan Ferrell (author) on January 17, 2018:
It may seem that the spark or fuel is being cut. You should try to retrieve any trouble codes from the computer memory to start a diagnostic, since the check engine light is coming on.
Dan Ferrell (author) on January 08, 2018:
There may be some trouble with a sensor.
Check for carbon build up inside the throttle body and under the trhottle plate.
Have you scan the computer memory for trouble codes.
Check it even if you don't see a check engine light on.
Babybo123 on January 07, 2018:
Have problem with my infinti since cold weather started idle rough and stalls have to keep revving the engine up after warm up its fine
Jorg on January 04, 2018:
Hi! I have a problem with a opel Vectra 2.0 2001 mod. When i drive, the car will suddenly shut down and the enginge light comes on. The only way i can start the car again is to take the key out, and then in again of the ignition. After this the car will run smootly again. The problems have occured several times.
I have replaced the crankshaft sensor but with no luck. I wonder if it could be the camshaft position sensor that causes this? Any tips would be appreciated!
Mason on January 02, 2018:
Hi Penny, I too had a similar problem with my car, where the engine would shutdown when coming to a stop. It would occur without warning and the check engine light was never activated. This happened to me 3 times over a 5 week period before I realized the car was low on oil and leaking too. Check/and repair leaks asap and top up your engine oil sooner.
Antonio on December 22, 2017:
I have a 97 Buick Skylark limited v6
What is the fastest way fixing this?
Alexis Velazquez on December 21, 2017:
I have a 2011 Kia sportage, it seems that a Camshaft Position Sensor B Circuit (Bank 1) went bad but my question is where is this sensor located? I know that there are two sensors (total) I have found one but not the other. Can you point me to any resources where I can find this info. Thanks Much appreciated.
Dan Ferrell (author) on December 20, 2017:
A bad crank or cam sensor can make the engine stop when failing. But low oil pressure can do the same thing on some models.
Have you checked for an oil leak? The fact that it had a normal level in November and a few days later was very low seems suspicious.
Keep an eye on the level. If you suspect a leak, have it checked. This might be the other reason (?) why the engine stalls.
penny on December 20, 2017:
I just had to get a cam position sensor replaced. It was so confusing as my car stopped DEAD in traffic, very scary. Got it towed. The codes showed CRANK position sensor and CAM position sensor. The mechanics put in the CRANK one. Two weeks later, it stalled again. Took it back. Code for CAM came up but when they tested it manually it all still worked so they said I did not need a new one and to try driving it again. So a third time 2 weeks later it stopped AGAIN. very scary again. So I took it to the Nissan dealer this time as I wanted to be sure. They replaced the CAM position sensor and said the car was very low on oil. I only had an oil change done in June (it is now December) and only 4,000 K since then. It was not low in end of November when I took it to the first garage. Bottom line I am very confused-and I hope the car is not going to stall again as I am afraid now to take it on the highway and will only drive it around town, I don' t have any confidence these are what was causing the problem as when they tested manually it was ok and your article also says it could be other things. This is on a Nissan X trial by the way which has been until now a fabulous trouble free car.
Dan Ferrell (author) on December 19, 2017:
Sometimes heat can do this to sensors. You may be lucky using some penetrating oil on the new one but be careful not to get any oil on the surrounding belts.
You may need to carefully drill the stuck sensor out.
Millie on December 19, 2017:
Could magnetic sensors sticking can come from bad oil or transmission oil need to be changed?
Dan Ferrell (author) on November 27, 2017:
Possibly the camshaft or crankshaft is not seated correctly. Some sensors come with a spacer to give the proper distance when installed. Some people remove this thin paper (?) spacer. Make sure the sensor(s) are seating correctly. If you removed the spacer or fell before installation, the sensor may have the sensing surfaced burned. Remove it and check it.
Craig on November 25, 2017:
I have a 1999 Nissan Wingroad that is giving me some trouble. The first thing i noticed is the tacho got a little jumpy. A little while after (a couple of weeks or so) the car would start surging and losing power when trying to accelerate at low revs. A couple more weeks after that the engine check light came on. Have had it looked at by the mechanic and they said the code suggested a cam/crank sensor problem. I have since purchased a pair of aftermarket sensors and after installation the car would crank but not fire. Help. Do i need to erase the fault codes before I carry out the installation? It seems unlikely that both replacement sensors are faulty.......