5 hours ago, DaveT70 said:

Every time you disconnect power you need to perform a transmission reset

But power performance is very important.

FULLY charge the good battery you have and fit it or bite the bullet and buy a new battery (fully charge it before fitting) then reset the transmission

Check earths and wiring as previously mentioned

 

On 10/7/2025 at 3:34 PM, Darren18 said:

Hi everyone I have a 2012 Ford S-max Powershift 2.0tdci.

start engine dash displays transmission limited function sometimes can reverse or drive forward most times don’t move at all when it does drive it will go into second gear then just rev up until drop back into 1st.

Plugged in diagnostic,

Fault code: P284B-00 shift fork C stuck in the powershift transmission.

P0949-00 trouble code indicates the auto shift manual adaptive learning not complete.

I have since dropped the gearbox oil and changed oil and filter. 

Does anyone have any knowledge of these fault codes and symptoms before I end up spending a fortune at a garage.

thanks

 

@Darren18 now looks like the codes relate to 2 shift forks (the other code isn't there)
Did you tear the filter apart when it was changed to see if there was anything (plastics) trapped in it?
Still looks like all of the electrical issues mentioned above need checking thoroughly before doing anything else  - are you going to do that or...? (there isn't anything other than the photo in your last post?)

Also with all due respect to @DaveT70 I have never needed to do any resetting after disconnecting battery?

13 hours ago, Shearers said:

Also with all due respect to @DaveT70 I have never needed to do any resetting after disconnecting battery?

It's recommended👍

On 10/8/2025 at 7:55 AM, DaveT70 said:

That's the issue, best to check and clean the solenoids first, if you're struggling for funds, in case it's just a sticking/faulty solenoid.

But it sounds like an internal failure though

That code is due to it not being able to select gears properly

Just also make sure battery voltage performance is excellent and all earths are in good condition

Check wiring under LHF wheel arch, main block connector, for broken/breaking down wires too

Where are the solenoids located are they inside the box?

Yes, inside

https://www.youtube.com/watch?v=jxCEdxT2_Rk

 

Hi all,

I recently bought a 2012 Ford S-MAX Titanium, and after the battery went flat, I started having transmission issues. I’m new to car DIY and learning as I go.

What happened:

Battery went dead after a week of no use. Tried a jump start and got a big spark at negative connection. Mechanic jump-started it, cleared codes, but check engine light stayed on.

On a test drive, the car became jerky, showing “Transmission Limited Function”. Managed to get home slowly.

Over a few days, the car moved only a little in reverse, then stopped responding, with whining noises (seems like gearbox). Codes keep returning even after being cleared.

What I’ve done so far:

Battery resting voltage ~12.3 V

Disconnected battery, planning replacement

Removed TCM-to-chassis cable (seems a likely culprit)

Took pictures of TCM/gearbox; seems replaced in 2022, some oil residue visible

Planning to install new battery and cable, then reset TCM

Don’t have OBD2 scanner — looking for a good one to clear codes safely

Questions:

Any recommendations for battery and TCM-to-chassis cable for 2012 S-MAX?

What could the oil residue on the TCM indicate?

Anything I can safely check while the battery is out?

Thanks in advance for any guidance!

 

 

 

Edited December 14, 2025Dec 14 by Essa
add pictures

There are now multiple OPs in this thread (maybe new threads are recommended but here goes anyway).

That cable does look very suspect, had similar looking one at battery positive.
Whilst I was able to get away with shortening that cable and soldering on a new lug, that earth cable needs to be flexible so maybe something like this:
https://www.ebay.co.uk/itm/295618439511

Get Forscan either Bluetooth App (can't program) or laptop /lead (can program) as standard OBD readers are persona non grata on here!:
https://forscan.org/home.html

Ask for recommended adapters as the Bluetooth one given is v. expensive, perhaps:
https://www.amazon.co.uk/dp/B08H82WC8L

Check battery earth, all heavy cabling, signs of damage to gearbox plug and wiring (will need testing if not an easy solution found)
Is oil at top just spillage?
When was oil and filter last changed, if no history change it to EXACT procedure, side plug is NOT a simple level plug!:
https://www.ebay.co.uk/itm/112436788478

You'll need to reset BMS when changing battery (crazy button pushing procedure) along with transmission reset above (but never done it)

Or ignore me, I don't care 😉

Oh and Welcome!...

49 minutes ago, Shearers said:

Or ignore me,

He's doing his best to 🤣

On 12/14/2025 at 8:22 PM, Shearers said:

There are now multiple OPs in this thread (maybe new threads are recommended but here goes anyway).

That cable does look very suspect, had similar looking one at battery positive.
Whilst I was able to get away with shortening that cable and soldering on a new lug, that earth cable needs to be flexible so maybe something like this:
https://www.ebay.co.uk/itm/295618439511

Get Forscan either Bluetooth App (can't program) or laptop /lead (can program) as standard OBD readers are persona non grata on here!:
https://forscan.org/home.html

Ask for recommended adapters as the Bluetooth one given is v. expensive, perhaps:
https://www.amazon.co.uk/dp/B08H82WC8L

Check battery earth, all heavy cabling, signs of damage to gearbox plug and wiring (will need testing if not an easy solution found)
Is oil at top just spillage?
When was oil and filter last changed, if no history change it to EXACT procedure, side plug is NOT a simple level plug!:
https://www.ebay.co.uk/itm/112436788478

You'll need to reset BMS when changing battery (crazy button pushing procedure) along with transmission reset above (but never done it)

Or ignore me, I don't care 😉

Oh and Welcome!...

Thanks for the detailed response and all the useful links — really appreciated 👍

I’ll take this step by step. First plan is to replace the battery and the suspect earth cable, then see if that resolves any of the issues before moving on further.Once the battery and cable are done, I’ll recheck the and report back with an update.

On 10/9/2025 at 10:14 AM, Shearers said:

Sounds like you need to really look hard at battery/Earth leads, all external wiring before anything else (although solenoids etc may still be necessary if the codes stick - pun intended!), much as as per:
https://www.youtube.com/watch?v=ikDCVb93mk0

 

Shearers

I'm getting an error message for this YouTube link. Can you post it again.

 

On 4/15/2024 at 5:12 PM, unofix said:

This is a video of the typical issues with the connectors on the Galaxy and S-Max

 

Unofix

Any chance you could share another link to this video? It seems to have been deleted.

The excellent channel SY Diagnostics was deleted by You Tube for reasons I don't know.
The specific video on Powershift wiring issue under the passenger wing due to one broken wire inside the connector leading to apparent failure of the entire gearbox isn't back yet.

I do however suggest that anyone reading this post should subscribe to get his numbers up again as he does some great work:
https://www.youtube.com/@sydiagnostics2025/featured

Unless it is deleted, I'm going to post that recommendation in its own thread.

8 minutes ago, unofix said:

Yes I'm a big fan of SY Diagnostics and over the years have linked to many of his videos. Sadly YouTube deleted his account when it was hacked and he lost all of his old videos.

The guy no longer works at a Ford dealership and so we will see very few Ford videos in the future.