I have a mk4 2019 Focus Vignale and have the below issues:

Before Christmas my car started with issues. When shifting the transmission from drive to reverse the vehicle would take a second or two to move into the correct gear and would rev in neutral before it shifted to reverse. This progressively got worse over a couple of weeks. Then after a couple of weeks when in drive after taking a hard left corner the car would slip out of drive into neutral whilst driving. When this happened a warning message came up very briefly stating an error with the drive management system. This got worse until the car would regularly slip out of drive into neutral whenever I was driving until all the warning lights came on and the car would not select any gear and could not be driven. I managed to get the car to a Ford dealer who after 3 weeks told me it was a fault in the TCM. The new module was ordered but then had to wait for the main Ford programmer to visit the dealer to reprogramme the vehicle. I got the car back and all has been well for 3 weeks. Now occasionally when I shift from drive to reverse I hear a brief warning chime but no message comes up and it seems like there is a split second delay before going into reverse. I am worried the same problem may be happening again as the original issue gradually got worse. Could this be a separate issue that is now affecting the new TCM? I bought the car 2nd hand and it was about 3 months out of warranty so had to fork out £750 for the new TCM. I am wanting to nip this in the bud early doors but I don’t have faith in the dealer as when I asked what the problem was with the old TCM they just said it’s a sealed unit and they only identify that was the issue and replace it.

 

Thanks

Personally I doubt if your TCM was in fact defective. The problems you describe can be the the result of damaged wires or corroded connections to the TCM.

Fitting a new TCM has probably for the moment just disturbed the wires or corrosion which then makes it seem like the unit has fixed the problem. Also I'm not sure why the dealer needed some top programmer to set up the new TCM, it is something that the dealer can easy do, and in fact many of this forum have done using the software FORScan.

All you can do is monitor the situation for the next couple of weeks.

If you get any warning messages, or any warning lights come on then it would be worth you getting FORScan and reading the DTC's and posting them here.

Thanks. The Ford dealer said they needed the master programmer as the code/ serial number they needed to erase the old TCM and install a new one was partly missing probably when the car was manufactured! I’ll see how the car does, no issues in the last few days but I don’t have a lot of faith at the minute. Is there a thread on here of how to use FORscan?

 

See also this link for other FORScan videos

 

https://www.youtube.com/@SYDiagnostics/search?query=FORScan