2015 transmission issues

[Todd]

My daughter 2015 fiesta has been giving her some random service transmission issue, she gets a warning on display saying “ transmission fault service now” it does not leave a code and always goes away. Today she experienced a loss of power then a sudden burst of speed, the car had the clutches and a few other items replaced about 2 years ago under warranty but I am wondering if this could be the control module which is still under warranty. Can they diagnose this issue or does it need to come in on a hook of a tow truck with codes? Any one have any insight?

 

[scotman]

Has she ever driven a traditional, three pedals under the feet, manual transmission?
If not, I would suggest that you go for a ride with her driving and observe her technique. Is she feathering the accelerator as she cruises along or maybe doing something like a squirt and lift, squirt and lift, type behavior? If so, she will need to adopt a more “deliberate” throttle control behavior. The power shift transmission has learning capable software in the controller. Unfortunately, it isn’t capable of learning a shift strategy in situations where the driver behavior is less than decisive. It will take around fifty or seventy five miles of deliberate throttle behavior, driving it like you are in a bit of a hurry. Accelerate from stops with the intention of getting up to the speed limit.
There is a shift strategy “teaching”process that Ford technicians use that involves a series of hard, wide open throttle accelerations. But I don’t know what kind of maintenance or mileage is on your Fiesta. So, I will not recommend that you do that. Just change her driving style to be a bit more aggressive and then see how the Fiesta responds. Please keep us updated!

 

[Todd]

My biggest concern is why is she getting “transmission fault service now” message randomly along with some erratic shifting, the car has 99000km (60000ish miles) she had the clutch changed out under warranty 3 years ago but still has warrant on the TCM, I am wondering if the TCM is causing the issues

 

[scotman]

Ghost codes are generally created by faulty ground connections. I would be cleaning the ground connections under the transmission first. Seal them up with petroleum jelly and see what it does.

 

[Handy Andy]

"Transmission Fault" issue can encompass a lot of little things - a message that is a catch all for issues that the built-in message minder won't tell you - it requires a ODB scanner tool to "catch" the reason in action - live data monitoring - so the code scanner you'll need is not cheap but you can borrow these tools from your local retail auto parts store.

In my instances of getting such a message, you feel the herky-jerky bottoming out accelerator dead pedal then it comes alive and roars off into the night...is one type of symptom.

But there are more clues as to how to localize this problem.

Does it occur when the engine is cold - as in not fully warmed up?

Drivability - ok when it's in the first 10 minutes - but stop-start city traffic then seems to cause the condition?

When it seems to be random, these types of code conditions are the hardest to track down, but not impossible.

What is odd, is that the codes get "tell-tale" on the console, but go away.

These conditions - are electrical-fault caused.

Many reasons but usually an interrupting condition - battery power that should be there to do this moment - but it now doesn't happen - kind of thing. So, I'd look into corroded connections in and around the battery, it's tray and the TCM connector itself - the battery cable goes by this housing - the main ground return for the engine and starter is that cable. So if the wiring bounces - so can that fault - it shows up but the diagnostics it runs later - doesn't show again.

This may relate to the TCM needing power - so the system defaults to that message, so how is the EPAS (Electrically Powered Assisted Steering) This system alone, sits just in front of you - it's in the steering wheel assembly - and just behind that dash.

It can take up to 60 Amps to pull off that battery terminal block to move the wheels when you're not moving - takes a lot of torque to do that - I'll let you guess the rest...

It can also be caused by a shared system that pulls power when the TCM needs it too, so upon acceleration or a quick turn, lights on, Brakes - the AC and the Heated seats? Any system pulling power at that time - the TCM pulls power to shift, finds none - so the power drops for that instant - that is a sign of required cleaning of electrical contacts and that may take time and effort but - this drop - fault - won't show until later and no memory of it - usually means the battery, electrical and the wiring are all suspects in this strange mystery...

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[Todd]

I took all the paint off the main ground and also the 2 grounds just underneath the brake fluid reservoir, she put a few miles on today and said everything was fine. Can the techs at my Ford dealer diagnose this tranny with there scan tool?

 

[scotman]

The dealership service department can diagnose it. But, you seem to be making progress with the issue. Clean electrical ground connections are so critical that I cannot find an emoji that is adequate to describe the importance of them.

 

[Todd]

I cleaned the main ground off the battery, and the 2 grounds just below the main, problem hasn’t come back since I did that, fingers crossed that was the issue.

 

[Handy Andy]

And be sure to check that RED battery Terminal post - you just need to find that little hole and stick a small tip flat-blade screwdriver in to release that tab and that red cover lifts straight up and off - you should inspect those connections too.

The reason why I brought up that EPAS this is; if the battery was ok, but still have those faults - you might also feel some shudder or even a type of pulse movement from the steering wheel - the steering rack is powered by the motors - WHICH assist the driver - so it those sensors and that controller - that do all the work to move steer the car.

You still have the steering wheel and the steering rack tied together - only thing though is a controller that is passive - so it only works when it has power but not interfere with your driving effort. So, it works to assist you but not like the older power steering which requires a pump and a belt off the engine to make it work, instead it uses the electrical power, and the motors are powered directly by that controller.

IF she drives with the lights on - the blower going and it's raining - and she feels a shudder in the steering wheel - that is due to the steering motors of the EPAS working - and that shudder is from the problem of they don't have enough power to move the wheel. So, the rack it' works on - then lets you feel the "tug" of the torque the motors can't accommodate for that effort of steering - you have to take up that slack - due to the lack of power for the motors to move those wheels.

So to tie a ribbon on this - if the battery power to the system was weak - it may not supply enough power to keep the system fully functional - so this also affects all the electrical systems too - and then the car tends to have a lot of "faults" - but only when there is a high power demand that the electrical system - due to the dirty connections - can't overcome - and that is where it needs your help - restore those electrical connections as good as possible and the system will pay you back and your daughter will thank you for it.

 

[Todd]

Hey thanks for the info, really appreciate it!