My friend owns a Ford Focus 1.6 Automatic (2013) in the UK. I am posting this on his behalf.

The car sometimes turns off when idling, stopped at a signal and does not turn back on. At times, it does not turn on when trying start the car all over as well. Weirdly though, what has worked is opening the car bonnet and shutting it. Or locking the car and getting in again.

This issue started after a battery replacement with a garage in London (National Tyres). We checked with National Tyres and Ford authorised service centres. We were asked to change the alternator in the car stating that old alternator was sending higher Voltage to the battery which resulted in the system turning off. However, the issue still continues.

Now, we have been asked to replace the Transmission Control Module. With the series of events, we are clueless as to what could be the problem. My suspicion is that it could be far too simple (sth like a wiring fault when replacing the battery). I am attaching an image of the error codes that the mechanics shared.

TCM is not in stock in most places and is frankly quiet expensive to replace. Anyone knows what could be the issue?

Very common with these is broken wires under the battery area to/from the TCM.

I am fairly sure though, that this is covered by Ford under the extended Powershift warranty/recall

I would've initially recommended to take the car to a Ford dealer for diagnosis, especially seeing how much they've charged you.

I would recommend a Ford diagnosis, then contact Ford UK CRC and see if they will cover the wiring or TCM replacement. A dealer will say NO, you have to contact Ford CRC yourself and, hopefully, get a case number.

If you get no joy, BEFORE YOU SHELL OUT ON A NEW TCM!!

1: An auto electrician (or someone who knows what they are doing) needs to "Bell-Out" all the wires from the transmission to the engine bay harness and PCM, concentrating under the battery area as this is the area where they are known to break due to tight routing.

2: replace any broken wires, make sure you solder the joints/splices

3: Ensure the battery voltage and performance is good as Powershifts are very sensitive to voltage

4: Remove the battery earth from the body, remove the paint from the body where the earth eyelet sits, grease body and re-fit earth

5: There are also further earth eyelets under the air cleaner box, remove the air cleaner box and do the same as item 4 on those earth eyelets 

6: Get Forscan and a PAID licence. Get a very good OBD lead, I strongly recommend an OBDLink EX for this as you are going to be performing updates.

7: Research carefully how to update module firmware on Forscan (MFU)

8: Update the firmware in the PCM and TCM

9: Perform a clutch relearn https://forscan.org/forum/viewtopic.php?f=6&t=1672

EDIT JUST TO ADD.

The initial battery fault could've just thrown the TCM out of sync so a clutch reset/relearn and adaptive shift strategy relearn may solve the problem.

Please perform items 4 & 5 before the relearn

 

On 2/2/2022 at 8:57 AM, DaveT70 said:

Very common with these is broken wires under the battery area to/from the TCM.

I am fairly sure though, that this is covered by Ford under the extended Powershift warranty/recall

I would've initially recommended to take the car to a Ford dealer for diagnosis, especially seeing how much they've charged you.

I would recommend a Ford diagnosis, then contact Ford UK CRC and see if they will cover the wiring or TCM replacement. A dealer will say NO, you have to contact Ford CRC yourself and, hopefully, get a case number.

If you get no joy, BEFORE YOU SHELL OUT ON A NEW TCM!!

1: An auto electrician (or someone who knows what they are doing) needs to "Bell-Out" all the wires from the transmission to the engine bay harness and PCM, concentrating under the battery area as this is the area where they are known to break due to tight routing.

2: replace any broken wires, make sure you solder the joints/splices

3: Ensure the battery voltage and performance is good as Powershifts are very sensitive to voltage

4: Remove the battery earth from the body, remove the paint from the body where the earth eyelet sits, grease body and re-fit earth

5: There are also further earth eyelets under the air cleaner box, remove the air cleaner box and do the same as item 4 on those earth eyelets 

6: Get Forscan and a PAID licence. Get a very good OBD lead, I strongly recommend an OBDLink EX for this as you are going to be performing updates.

7: Research carefully how to update module firmware on Forscan (MFU)

8: Update the firmware in the PCM and TCM

9: Perform a clutch relearn https://forscan.org/forum/viewtopic.php?f=6&t=1672

EDIT JUST TO ADD.

The initial battery fault could've just thrown the TCM out of sync so a clutch reset/relearn and adaptive shift strategy relearn may solve the problem.

Please perform items 4 & 5 before the relearn

 

Thanks a lot. I'll check with a local garage about this relearn things and wires.