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Meaning of Common OBDII "Check Engine" Codes on the Toyota Camry

Hardlymoving writes about do-it-yourself automobile maintenance on various makes and models.

Camry OBDII Input Port

Camry OBDII Input Port

Toyota Check Engine Light Codes

This article will address the most common error or "fault" codes that trigger the illumination of the "Check Engine" light on the four-cylinder Camry.

All modern automobile engines are managed by an on-board computer, commonly called an Electronic Control Module (ECM) or Powertrain Control Module (PCM). The PCM controls both the engine and the transmission. It generates the error codes or fault codes we talk about here.

Electrical inputs go to the PCM from sensors located throughout the engine compartment. The PCM processes the inputs (in milliseconds) and sends electrical signals (voltage) to electronically controlled valves and relays to make the engine behave in a predictable manner. When all of these engine control devices are working in harmony with the PCM, the fuel economy, emissions and overall driveability of the Camry perform at optimum levels.

When the PCM expects electrical input signals from the sensors but doesn't receive them, doesn't receive them fast enough, or doesn't receive them in the voltage range it expects, the PCM generates a fault code and stores it. The yellow "Check Engine" light comes on to inform the driver of the Camry about the fault.

If multiple output sensors fail, the various fault codes will accumulate in the PCM until the problem has been identified and fixed and the fault code(s) erased.

Besides sensor failures, the failure of input control valves and relays (which get PCM instruction data via electrical current) will generate fault codes as well.

There are both generic and vehicle-specific fault codes. Generic fault codes are common to all vehicles that use the OBDII (On-board Diagnosis Version II) system based on SAE (Society of Automotive Engineers) and Federal EPA standards. Vehicle-specific codes are additional codes added by the auto manufacturer to address specific vehicle functions not common with other vehicle makes and models.

Common Sensors That Give Input to the ECM

  • Oxygen Sensor (O2) (at least two)
  • Crankshaft Position Sensor
  • Camshaft Position Sensor
  • Air/Fuel Sensor (in California cars it replaces one of the O2 sensors)
  • Engine Coolant Temperature Sensor
  • Intake Air Temperature Sensor
  • Throttle Position Sensor
  • Manifold Absolute Pressure Sensor
  • Vehicle Speed Sensor
  • Exhaust Gas Recirculation Valve Position Sensor
  • Power Steering Pressure Switch
  • Transaxle Sensors

Common Valves, Sensors and Devices That Receive Output From the ECM

  • Ignition Coils
  • Fuel Injectors
  • Idle Air Control Valve
  • EVAP Vacuum Switching Valve
  • Vapor Pressure Sensor

5 Problems That Commonly Cause Fault Codes in the Camry

The fault codes generated by the OBDII only indicate possibilities: a possible problem or set of problems that require attention. Identifying a specific cause, in the absence of some expensive analysis tools, may require component testing as well as trial and error.

Some repair facilities, including dealerships, take the "shotgun" approach—which is to replace every possible item that may have caused the fault code to go on. Their focus is to avoid revisiting the problem and having to deal with you, the customer, more than once. In other words, why spend two hours identifying a problem whose solution might require merely cleaning a part, or replacing a $10 part? However, some of these parts can cost hundreds of dollars.

These are the most common types of fault codes encountered with the Camry, along with their remedies. In this list, X = a number from 0 through 9.

  1. P013X and/or P015X with P113X: The O2 sensor (Oxygen) or Air/Fuel sensor (California emission cars) has gone bad. O2 sensors are wear items and do not last forever. They usually go bad approaching 80,000 miles. Just buy a new one and replace it. They can't be cleaned. Going a few months without replacement runs the risk of destroying the catalytic converter. When the ECM gets a weak or inconsistent signal from the upstream 02 sensor (the one before the catalytic converter), the ECM will send an "enrich fuel" signal command to the fuel injectors so that an overly lean air/fuel mixture won't overheat the engine. Fuel economy will significantly deteriorate. And when the combustion exhaust gases containing unburned fuel pass into the catalytic converter, the converter will overheat in the process of continuously burning combustible pollutants. In time the converter will burn out. When buying a new 02 or Air/Fuel sensor, get Denso or NGK. Bosch sensors don't seem to work well in Hondas only last a couple of years with Toyotas. The warranty period for most electronic components is 90 days to 1 year.
  2. P044X: Determine if your fuel cap is loose. If that doesn't fix it, then it's probably the VSV valve (part of the EVAP system) attached to the charcoal canister that has gone bad.
  3. P030X: A spark plug or spark plug wire is bad. I've seen wires go bad when wire clips were broken off during spark plug replacement. The wire(s) then rest on the hot valve cover and get slowly destroyed by the heat. In a worst-case scenario, the check engine light will blink continuously; this indicates the car should be serviced as soon as possible or the catalytic converter will go bad in short order. Multiple P030X or the "Random Cylinder Misfire" code usually indicates a bad coil pack. Since coil packs are expensive, the ignition wires are a good starting point for replacement. You can't use the old voltage resistance test to test ignition wires that use the new technology.
  4. P0420: This may indicate a bad "downstream" (after the catalytic converter) 02 sensor (which monitors the efficiency of the catalytic converter) or it may mean a bad catalytic converter. It is all guesswork in the absence of an exhaust analysis tool (like what they have at DMV) to determine the efficiency of the converter. Here's a possible fix for the P0420 problem.
  5. P0401 and P0402: This one can be a little tricky. Either the EGR (Exhaust Gas Recirculation) valve requires replacement, or the VSV (Vacuum Switching Valve - EVAP system component) isn't working properly. Replacing the EGR valve (which isn't cheap) may not resolve the problem unless the VSV valve is also replaced. The purpose of the EGR valve is to recycle a small amount of engine exhaust back into the air/fuel mixture to keep the exhaust temperature from rising high enough to produce too much of a pollutant called nitrogen oxide. The possible cheap solution: mixing 4 ounces of Marvel Mystery Oil with every 10 gallons of fuel may resolve the problem after a few tank fill-ups.
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To Buy or Not to Buy an OBDII Code Reader

ODBII standards were implemented in 1994 to replace ODBI. We don't know of any ODBIII on the horizon.

OBDII code readers have significantly come down in price compared to a few years ago. A basic reader to just extract and reset the code is around $30. A reader that gives the text description accompanying the code is around $50. Car dealers charge around $50+ for each reading.

But most automotive retail parts stores will download and reset the code(s) for you for free. Why have your own reader? It's nice to have your own reader if you intend on owning a motor vehicle for a while, but it's like buying a wrench—you don't need to use it all the time.

Once the reader or the parts store has identified the fault code, go on the internet to get the fault description with some possible solutions to investigate.

Sometimes the fault codes are anomalies; after you reset the code, it never comes back on. But if the code quickly reappears, then some maintenance work is in order. In either case, you have avoided at least one trip to the dealership, repair shop or parts store.

One method of resetting fault codes without trying to find out what the codes were is to disconnect the car's battery... if re-entering your car's radio stations and anti-theft code isn't a hassle.

The Meaning of the Digits in the OBDII Fault Code






0, 1

0 = All Manufacturers (generic)



1 = Specific Manufacturer



Emission System



Fuel Injector Problem



Engine Misfire / Ignition Problems



Emission Control



Speed and Idle Control










Non-Manufacturer-Specific Fault Codes



Mass airflow (MAF) sensor circuit manfunction


Mass airflow (MAF) circuit range/performance problem


Manifold Absolute Pressure (MAP) sensor circuit malfunction


Manifold Absolute Pressure (MAP) sensor malfunction


Intake Air Temperature (IAT) sensor circuit malfunction


Engine coolant temperature (ECT) sensor circuit malfunction


Engine coolant temperature circuit range/performance problem


Throttle/pedal position sensor (TPS) circuit malfunction


Throttle/pedal position sensor (TPS) range/performance problem


Insufficient coolant temperature for closed loop fuel control


Thermostat malfunction


Heated oxygen sensor circuit malfunction (bank 1, sensor 1)


Heated oxygen sensor slow


Heated oxygen sensor heater circuit malfunction (bank 1, sensor 1)


Heated oxygen sensor circuit malfunction (bank 1, sensor 2)


Heated oxygen sensor heater circuit malfunction (bank 1, sensor 2)


Heated oxygen sensor circuit malfunction (bank 2, sensor 1)


Heated oxygen sensor circuit slow response (bank 2, sensor 1)


Heated oxygen sensor heater circuit malfunction (bank 2, sensor 1)


System too lean


System too rich


System too lean (air/fuel lean malfunction, bank 2)


System too lean (air/fuel rich malfunction, bank 2)


Random or multiple cylinder misfire detected


Cylinder no. 1 misfire detected


Cylinder no. 2 misfire detected


Cylinder no. 3 misfire detected


Cylinder no. 4 misfire detected


Cylinder no. 5 misfire detected


Cylinder no. 6 misfire detected


Knock sensor 1 circuit malfunction (bank 1 on V6 Models)


Knock sensor 2 circuit malfunction (bank 2, V6 models only)


Crankshaft position sensor A circuit malfunction


Camshaft position sensor circuit malfunction


EGR insufficient flow detected


EGR excessive flow detected


Catalyst system efficiency below threshold


EVAP system malfunction


EVAP control system - incorrect purge flow


EVAP system - small leak detected


EVAP system - vent control malfunction


EVAP system - pressure system malfunction


EVAP system - pressure sensor range/performance problem


Vehicle speed sensor malfunction


Idle control system malfunction

Toyota-Specific Fault Codes



BARO Sensor Circuit


Accelerator Pedal Position Sensor Circuit


Accelerator Pedal Position Sensor Range/Performance Problem


Throttle Control Motor Circuit


Magnetic Clutch Circuit


ETCS Actuator Power Source Circuit


Throttle Control Motor Lock


Electric Throttle Control System


Air/Fuel Sensor Circuit Range/Performance(Bank 1 Sensor 1)


Air/Fuel Sensor Circuit Response (Bank 1 Sensor 1)


Air/Fuel Sensor Heater Circuit Response. (Bank 1 Sensor 1)


Air/Fuel Sensor Circuit Range/Performance. (Bank 1 Sensor 2)


Air/Fuel Sensor Circuit Response. (Bank 1 Sensor 2)


Air/Fuel Sensor Heater Circuit. (Bank 1 Sensor 2)


Fuel Pump Relay Circuit


Igniter Circuit Malfunction - No. 1


Igniter Circuit Malfunction - No. 2


No Crankshaft Position Sensor Signal - Engine Running


VVT System


Sub-Throttle Position Sensor


Sub-Throttle Position Sensor Range/Performance Problem


Turbo Pressure Sensor Circuit


Turbo Pressure Sensor Range/Performance Problem


EGR Valve Position Sensor Circuit Malfunction


EGR Valve Position Sensor Circuit Range/Performance


Starter Signal Circuit


Boost Pressure Control Circuit


Boost Pressure Low


Boost Pressure High


Stop Lamp Switch Signal Malfunction


Cruise Control Main Switch Circuit


ECM BATT Malfunction


Knock Control CPU


Traction Control System




Idle Air Control Valve Control Circuit


OCV Circuit


Wastegate Valve Control Circuit


EGR Circuit


EGR by-pass Valve Control Circuit


Park/Neutral Position Switch Malfunction (Only For A/T)

This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.

Questions & Answers

Question: Is a 2001 Solara with an error code of P1130 an easy fix?

Answer: Yes. Clean or replace the MAF (Mass Air Flow) sensor.

Question: What is code C1300 on a Toyota Camry?

Answer: A a non generic manufacturer's specific code for a particular model vehicle.

Question: Why does my Camry 2003 model keep vibrating on the move?

Answer: The wheels may need to be re-balanced.

Question: I got code p0446 on my 2002 Toyota Solara SLE. How do I fix it?

Answer: You need a new evaporator system canister vent control valve.

Question: What is "Code 96" on a Toyota car?

Answer: There is no such thing.

Question: What is 0440 Eva system failure? What reasonable repair cost should I anticipate? Also code P0773? I have a 1999 Toyota with 191K. Timing was done at 120K. Should I consider doing while the engine is apart?

Answer: P0440. The (EVAP) emission control system prevents the escape of fuel vapors from a vehicle's fuel system. Fuel vapors are routed by hoses to a charcoal canister for storage. Later, when the engine is running a purge control valve opens allowing intake vacuum to siphon the fuel vapors into the engine. The EVAP system consists of many parts, including (but not limited to) the gas cap, fuel lines, carbon canister, purge valve, and other hoses. This code will not impact engine performance but will prevent you from passing DVM emission testing. The cost of repair varies upon what is malfunctioning and the cost of the specific part that needs to be replaced.

P0773 is a transmission related error code. The causes could be:

Low transmission fluid

Dirty transmission fluid / filter

Frayed wiring / damaged connectors

Failed solenoid

Failed transmission pump

Pressure blockage

Valve body issue

TCM or ECU failure

If the transmission fluid contains any dirt, sludge or metallic debris, the solenoids may not function properly. The presence of metal shavings could also indicate internal component failure, which is why checking the ATF level and condition should be the first step in diagnosing a transmission solenoid fault code. If the fluid is dirty and pressure blockages are suspected, then a transmission flush may be performed.

If there are no obvious maintenance related issues, then the wiring and connectors should be checked for evidence of damage and/or corrosion. If everything appears fine, then the shift solenoid will need to be tested according to the manufacturer’s procedure. If no issues have been found by this point, then the problem could lie with the transmission pump, valve body, or pressure regulator.

Question: what causes the P0172 - system to rich fault?

Answer: If the upstream o2 sensor is not working properly, the car's ECM will over enrich the mixture to protect the engine until the o2 sensor provides a more reliable signal.

Question: What Coulld Be The Problem Why My Lexus 300 Speedometer Refuse To Move?

Answer: Check out the speed sensor.

Question: How do I fix a code p0057?

Answer: Change your bank 2 oxygen sensor.

Question: Where is the second nox sensor?

Answer: Usually under the intake plenum.

Question: What causes ABS and anti-skid lights to illuminate?

Answer: ABS malfunction. Must have the system scanned to determine malfunction.

Question: I got a 442 and 446 check engine code. The dealer said it was emission related. Gas cap is ok. Any ideas for me to try?

Answer: VSV (vacuum switch valve) ... charcoal canister ... vacuum tube lines ...

Question: What exactly does code P0171 mean on my 2009 Camry?

Answer: Your air/fuel mixture is too lean. You've got a air vacuum leak somewhere. Check your air intake hose for cracks and rubber vacuum links for leaks.

Question: Working with a 2000 Toyota Solara that's giving these codes: p-1130, p-1135,p-1150 &p-0125 any suggestions?

Answer: Upstream O2 (or air fuel ratio) sensor(s) not working.

Question: I have a 2008 Toyota Camry getting code p0335. Put a new sensor in it, but still getting p0335. How do I fix it?

Answer: Sounds like you have a bad crankshaft position sensor.

Question: I'm getting a P0121 error. What can I do to remedy this problem?

Answer: Replace your throttle position sensor on your throttle body or check the electrical fitting.

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