John does many other things, but meanwhile he earns his sandwiches fixing automatic transmissions.
The powershift transmission is one of a growing number of dual-clutch transmissions that are expected to be fitted in more than half of cars in Europe by 2020. These transmissions are favoured for their improved efficiency and quicker, smoother shifting than more traditional automatic transmissions. It’s because of this popularity that it’s increasingly useful to know what kind of faults you’re likely to see in these transmissions, and the symptoms they produce. After all, there’s a growing chance you might have one in your car.
But before we get into that, let’s briefly go over how the Powershift automatic transmission works.
How The Powershift Transmission Works
Because it's hard to explain what's wrong with something if you don't know how it works.
Let's quickly touch on the naming of this transmission. It is commonly referred to as powershift. However, the proper name for the transmission I'm referring to in this article is 6DCT450. There are also variants called 6DCT250 and 6DCT470. These variants have differences, however, most of what is detailed below can be applied to all variants.
The main difference lies in the clutch assembly. The information below regarding repairing the dual clutch assembly applies only to the DCT450 and DCT470. There are no repairable components for the DCT250, which uses a dry clutch assembly, and can only be replaced.
How it Works
A typical automatic transmission has a series of “wet clutches” that are activated in particular combinations to achieve the desired ratios. Conversely, a manual transmission has one dry clutch and a bunch of actual metal gears. Dual clutch transmissions like the powershift are a combination of the two.
A pair of clutches are used together, with one clutch being responsible for the odd-numbered gears and the other one for the even-numbered gears. These clutches are controlled by the transmission control unit, rather than a foot-powered clutch pedal.
This hybrid of transmission designs allows for the increased efficiency of a manual transmission, the ease of use and driving comfort of an automatic transmission, as well as quicker, smoother shifting over a regular automatic transmission.
When they’re working correctly, they give the driver the best of both worlds. But when they’re not, they can be a nightmare. And the first stop on the road to ending that nightmare is working out what the problem is.
Common Powershift Faults
The most common faults I've seen in powershift transmissions.
Sensor Problems, Part I
If you find your powershift transmission going into failsafe mode (also known as “default,” and “limp mode”), and a diagnostic scan reveals trouble codes relating to sensors or shift positions, your first port of call should be to check the service history of your vehicle.
Powershift transmissions—more so than regular automatic transmissions—need regularly servicing (roughly every 30,000 miles). If your powershift transmission has not been serviced regularly enough, or if it has spent a lot of its time in shift-heavy driving (such as around town, in traffic, etc.), you may simply have too much contamination in your oil.
Unfortunately, if you’re getting faults, it’s already too late to simply change the oil and filter.
Inside the transmission is a number of sensors for reading the position of various internal components. They do so by picking up readings from little magnets, but those magnets can get covered in tiny bits of metal that gets into the oil.
Now, don’t panic, the tiny metal filings are not a problem—that’s just regular wear and tear—but the build-up of this debris interferes with the sensors and confuses the control module.
In short, the sensors and magnets will need cleaning.
It’s sometimes possible to clean them off without removing the transmission, by removing the plastic sump and valve body, but if there is a lot of debris in the transmission, it may need stripping down completely.
Keeping on top of oil/filter changes should prevent this problem from occurring in the first place, however.
Servicing a Powershift Transmission
Juddering/Shuddering on Take Off
For clarification, when I say “on take off,” I mean when you are transitioning from stationary to moving. This particular judder can vary in severity from a light shaking that is barely noticeable, to a violent shaking that can rattle the whole vehicle. You will generally find that the lighter you are on the throttle, the less severe the juddering. Crawling away from a standstill on light throttle might not produce a judder at all while putting the pedal to the metal and trying to spin the wheels might cause an almighty bang. This is to do with pressure and is why you might still find you get a juddering when trying to set off on a hill, even if under light throttle.
This fault is caused by a faulty clutch assembly. The actual fault will determine how expensive a problem this is.
Firstly, the transmission will have to be removed to get at the clutch assembly. If the fault is simply worn clutch plates or broken damper springs, those individual components can be replaced without swapping out the whole assembly, which cuts down the cost of parts considerably. There are also other parts that can be replaced, such as the clutch-apply pistons.
The clutch assembly itself can often wear down, however, and when this happens there is nothing for it but to replace the whole assembly.
Sensor Problems Part II
Let’s say you’ve looked at the symptoms of your misbehaving powershift transmission and you’ve concluded that it matches up with what I described in the above Sensor Problems Part I section. But you’ve had the sensors cleaned and the oil changed, and it hasn’t helped in the slightest.
Unfortunately, this is a control module fault. And it’s rarely cheap.
The control module is essentially a little computer that sits inside the Powershift transmission, listening to all those sensors and taking information from the engine, and ultimately deciding what gear to be in and when to change. It’s the brain of your automatic transmission.
So, as you can imagine, it’s not good when it goes wrong.
There’s really nothing for it but to replace it. At the time of writing this article, I am not aware of anybody who can repair these units, so you’ll need a new one. And it is a new one, as these modules are coded to the vehicle they are fitted in, so you can’t buy a second-hand module, stick it in your vehicle, and hope for the best. Furthermore, they come completely blank (like a Windows computer without Windows installed), so you’ll need to get the software installed, which requires special manufacturer diagnostic tools.
This is not a job for the home enthusiast.
The control modules also come with the hydraulic component (whether you want it or not), which brings me onto the next fault.
If your transmission is shifting poorly, typically resulting in harsh, thudding gear changes, there’s a good chance you have a faulty valve body on your hands. The valve body is the hydraulic, physical aspect of the control module.
Picture the transmission as a big machine with a lot of controls. The control module mentioned above is a manager with a megaphone, bellowing orders out. The valve body is a small army of people at the controls to that machine, flicking switches and pulling levers under the manager’s orders.
The valve body will typically need replacing, especially if the problem is caused by wear and tear. However, in Powershifts where the debris mentioned above has been allowed to build up excessively, it may be possible to dismantle the valve body and clean it out. A much cheaper prospect, because you can’t buy a valve body without buying a control module!
Other Useful Information
Not exactly common faults, but if your vehicle has a powershift transmission, it won't hurt to know the following...
ATSG Learning: Powershift DCT450 and 470
If you’ve noticed transmission oil leaking from your vehicle, be sure to get it fixed as soon as possible. The oil in an automatic, such as a powershift, is not just lubricant, it is also the hydraulic fluid used to operate the internal components. If it is allowed to drop too low, the transmission will start to misbehave, and will likely damage the clutches if driven enough with this fault.
Crunching and Whining
Noises when driving, such as crunching sounds when changing gear, or whining noises when under load, indicate a problem with the mechanical gears themselves. These may be deceptive as the transmission could operate perfectly well despite these noises, but they should be dealt with as soon as possible. As mentioned at the top of this article, these gears are hefty lumps of metal. If they break, they could cause all sorts of damage to everything inside the transmission, not just themselves.
Gear Selection Issues
If your gear selection doesn’t seem to register correctly, it’s probably just the cable that runs from the selector to the transmission that needs looking at. In those cases it can often be simply adjusted or, at worst, a replacement cable is needed.
If you’ve had work on your Powershift, however, and the selector is not reading right after said work, there is a good chance that whoever performed the work did not get the transmission range switch properly aligned before putting your Powershift back together. For that, refer to a Powershift manual on how to properly locate the switch.
And that concludes my list of the most common faults I’ve seen working with these transmissions. Remember, this isn’t a comprehensive encyclopedia of every fault you might come across in a powershift transmission, but it is, for now, the most frequently seen faults for this technician.
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.
Tony on August 25, 2020:
I have a 65 Plate, 2015 Mk4 Mondeao Estate Powershift with paddles. I bought it 6 months ago from a main dealer with 42k on the clock and since then I have done 4k. I got the message "Transmission Limited Function" on the dash and when it changes up it slips in every gear. The main dealer told me the soilenoids have gone and it would need a new gearbox at a cost of £5500. When I asked for more information I was then told it wasn't the soilenoids but the speed sensor which comes as part of the gearbox which is why it needed a new one. Having only just bought the car this repair is going to cripple me, any advice welcome.
Ami on July 09, 2020:
Hi I got 65 2015 ford galaxy 2.0 diesel power shift car is not selecting any gears
Spynutz on July 06, 2020:
Tony's... I have 2013 with identical fault would love to know if u found solution be much appreciated
Sueyefc on April 12, 2020:
I have a 2011 Grand Cmax auto power shift!
It as just dropped its transmission fluid. The leak seems to be coming from between the gear box and engine. Is it time for a new box?
The problem occurred whilst driving down road I felt a slip, like the clutch had slipped, pulled up at lights a few seconds later, the car failed to move once I selected D, had to switch engine on an off to get drive, managed to get car safe before before it happened again. There are 3 error codes showing, all shift solenoid.
Judson on February 16, 2020:
My 5L40 gm box was serviced 4months ago..but now it just dis angage while driving after few miles..then after switch off and wait few minutes will go again
Vitezslav on February 06, 2020:
Hi, I would like to ask, what can cause this problem. When I move the lever from position D/S to N/R or P there is a strange sound and transmission shaked. During driving everything is OK. From position R it is also silent and OK. I was in service and they suggested to upgrade software, if not help, then change mechatronic. It is Mondeo MK5, 2016, 110kw. Thank you
per-arne Olsen on January 24, 2020:
I have a Mondeo 2015 AWD 180 hp diesel whit powershift. My problem came after dealer used not orginal parts when changing timing belt and water pump the engine ran hot and they had to replace the topp of the engine an the cooling was ok...but after i have the car back the powershift Auto start to fail..(services and oil changes has been folloved) it slipping into neutral somtimes -i let go of the trottle for 5-8 seconds and its ok again-but more serious problem is that it go in to emergency mode shut down power(not often) and i need to turn of the car and start it again before driving of again-the Ford dealer has tried to re programe the gearbox and tell me its not their problem....Any tips?
Steve on January 06, 2020:
I have a 2011 140TDCI Galaxy with Power-shift.
It has a full service history and 72,000 on the clock. Over the last few weeks it has developed vibration under acceleration between 50-70mph. Its seems to be on the offside only. Having checked the CV joint gaiter had perished and blown all the grease out of the CV joint. I have taken this in to be repaired and the garage are telling me its the gearbox not the CV joint thats the issue. The vibration is worse when going uphill, so is it possible that the Fluid needs changing?
Tonys on December 08, 2019:
Hi I have a ford galaxy Powershift 2012. the transmission works fine no change problems, nice and smooth. however 1st thing every morning when cold the transmission fault warning comes on after e couple of hundred yards. if I stop turn the ignition of and restart its all fine. sometimes when its really cold it'll do it a couple of times, then its fine for the rest of the day?
Lloyd cisco on November 18, 2019:
Had a new focus 22k we paid at 11thousand miles deler offerd 6 thousand if they were able to fix transmission no one can fix that getrag trans its junk way to complex no ford in my drive way just like eco bust junk
Bevpaul on October 23, 2019:
Hi, I have a 2003 fiesta lx semi auto and the last week it either doesn’t let you push accelerator pedal down as tho something is stopping it just for a second when in 3rd Auto gear or it will be in 3rd auto and Just rev for no reason by its self even tho it is in gear. I would be greatfull for any info how to put this right..
Tom on October 10, 2019:
@Downundersir Have you managed to find the problem?
SparkyChris on September 12, 2019:
Hello. I have a 2010 ford smax titanium with the powershift transmission.
Ive only owned it since may and only recently im having problems. 1st and 2nd gear pull fine but 3rd 4th 5th and 6th gears feel like the clutch is slipping? The revs have started jumping up and down and power is certainly less in these gears, i have to put my foot down harder so to speak.
Obviously i need to get it to a garage but do you think it is the clutch? Or possibly something else youve mentioned?
Aamir Malik232 on August 29, 2019:
I also changed a solenoid valve (G6T46174 JC7 JP). Could this be the source of the problem?
Aamir Malik232 on August 29, 2019:
My car is a 2006 Ford Galaxy 1.9 tdi automatic (auy)
John Bullock (author) from Yorkshire, England on August 28, 2019:
Hi. I'm having a bit of trouble working out what model transmission you have there, based on the fault you've described. Could you let me know what transmission it is?
Aamir Malik232 on August 25, 2019:
I am a mechanic and i have a ford galaxy 1.9 tdi automatic but i dont have much knowledge on automatic transmission.
I replaced my mechatronic and behind it there is a green rod with a chunk of it coming out with round edges for each different gear to lock in place.
However, it turned in the opposite direction and this means that when i start the car, it doesnt move when i shift gears. When i fix the rod's position, the gear lever above it cannot move properly because there is a difference in the distance between the nut and the rubber part (connected to the gear lever wire) that connects both together by a turning metal part.
I do not know how to fix the rods position so that the car can start shifting gears and moving again.
If you have any idea on how to solve this issue, please let me know.
I can send pictures if you provide me a way to do that to make things easier.
Rob on June 29, 2019:
Hi my mondeo powershift box sometimes wont go into even number gears ie. 2,4,6 and even had gone into 7th gear (6 speed only) trans has been serviced and is a lot better but still fails when hot also has a slight slip under medium throttle no slip under high or low throttle,
Is there any options other than full rebuild?
Colton on June 27, 2019:
Hi my POS focus does at least 3 of these things not even including the grinding sound it makes when shifting gears
Ahmad on May 30, 2019:
I have Ford galaxy Powershift Automatic Transmission. when driving sometimes i feel the gearbox does not change the gear and make a loud sound in Engine. Any tips or idea ?
Downundersir on April 26, 2019:
Dct450 Mondeo tdci 163. Lost reverse first, then 4th then 2nd. Occasionally once warm & left on incline Reverse is available but not with any regularity. Has been serviced with new oil/filter at regular intervals, currently has 150000klm. Now CEL but no transmission limited function.
Adam on April 17, 2019:
My vehicle seems to just jump at the point of moving from stationary occasionally depending on how heavy my foot is on the pedal. What could this be? I am not having issues with the changing og gears.
FAOUZI on April 03, 2019:
Hi, i lost the odd gear and the reverse too.
The 2,4 and are perfect.
I disassembled the box because the plastic retainers in the clutch broke into pieces.
Replace the friction and steel plate, retainers and springs and the internal filter.
I sent the mechatronic to a specialist to clean it and check the valvebody.
Put back the gearbox , i drove down the road but cant reverse and no odd gear.
The fault code is P0841.
Could you help me with this.
Johince on March 22, 2019:
I recently bought 2010 Renault Magane 1.5 dCi done 56k which got a 6DCT250.
I was getting gearbox fault every day on cluster and the car won't engage even gears.
Upon inspecting the gearbox I found the top bold of the control module was missing and gear box oil leak.
I fitted a new bold and topped up the oil. Also, swapped odd and even clutch actuators between them.
This helped to get the frequency of fault appearance reduced to once in a week still in even gears.
Not planning to chnage the shaft seal to clutch bell housing soon to arrest the leak.
Now, just supecting of any oil ingress to contol module.
Any body have any comment on this?
Dee on February 08, 2019:
I found that brilliant, but still not sure of the problem. I suspect EGR. I have a 2018 automatic Galaxy Titanium x power shift that has done 10k miles. I do short journeys, and the MPG is now at least 100 miles less per £70 worth of diesel ! Gear changes are no longer always smooth, juddering at low speeds in traffic/going up hill and at faster speeds the change of gear often follows a short over rev of the engine. If I put my foot to the floor it picks up and is a bit smoother. It also brakes far more with the gears going down slopes/hills. Any comments grateful as the dealer (its a motability car) has just advised at the first visit that it was the computers not talking to each other! Mmmmm!
Robert on January 17, 2019:
I have a 2015 Ford C-Max with PowerShift.
Now can only switch to 2,4 and 6.
So, no 1,3 and 5 available.
Any idea what could the problem be?
gary on December 09, 2018:
are 2017 Focus still having issues?
kevin on November 14, 2018:
6dct needs oil and filter at 130k mi,, you say change which? filter and oil at 30k mi?
Jyoti Shrestha on October 08, 2018:
I suddenly received transmission malfunction on ford fiesta 2011. After that i feels the gear shift is not proper that cause rpm goes higher. It feels like the gear shift is only 1,3,5 and misses 2,4,6. What vmcan be the cause and what do i have to replaced
Christopher on September 24, 2018:
TCU can be flashed with Mitsubishi's PassThru CAN software to use second hand modules, and some shop do repair the valve body assembly by testing and replacing faulty solenoids.
Steve on September 09, 2018:
How many kilometers have you listen 6dct450 have been driven ?
Davebrave on May 24, 2018:
Hi, my Mondeo has over 50.000km and it's from 2011. I recently changed the Powershift oil (I know, I missed one change :( )but even after the oil change I'm experiencing some problem when shifting gears. It has happened only once in a month after the change: the problem is when shifting (manually) from third into fourth the gear either engages abruptly or it doesn't shift straightaway going into neutral for some seconds (the engine revs up) and then shifting into fourth. I get no errors on the dashboard (nor even DTC codes) and apart from that, there is no unusual noise, grinding or vibration coming from the drive train. Do you think it might be the springs on the clutch?