P38A 2.5 auto converter lock up solenoid fault

Hoping someone can help.

I’ve a 2.5 auto diesel that appears to have gone into limp mode and won’t change gear. Nanocom reads solenoid lockup fault

We initially removed the valve plate, cleaned and tested the solenoid which seemed to work ok. Changed the fluid and filter and put it all back together. This made no difference.

I then purchased a valve plate thinking there was something wrong with it, replaced the plate and it made no difference.

As I’ve a couple of parts cars, we then replaced the entire gearbox and transmission, again this made no difference and still have the same fault.

Then replaced the gearbox controller ECU, again this made no difference.

Fuse 6 beside the BECM is the main fuse for the gearbox. It's been replaced but was fine.

Running out of ideas and getting a bit desperate, any advice would be greatly received.

Norrie570 said:

Hoping someone can help.

I’ve a 2.5 auto diesel that appears to have gone into limp mode and won’t change gear. Nanocom reads solenoid lockup fault

We initially removed the valve plate, cleaned and tested the solenoid which seemed to work ok. Changed the fluid and filter and put it all back together. This made no difference.

I then purchased a valve plate thinking there was something wrong with it, replaced the plate and it made no difference.

As I’ve a couple of parts cars, we then replaced the entire gearbox and transmission, again this made no difference and still have the same fault.

Then replaced the gearbox controller ECU, again this made no difference.

Fuse 6 beside the BECM is the main fuse for the gearbox. It's been replaced but was fine.

Running out of ideas and getting a bit desperate, any advice would be greatly received.View attachment 269368View attachment 269369

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Did you also change the torque converter? The fault relates to the torque converter according to your diagnostic photo.
Needs @Bemble

You need to go through the wiring with a fine tooth comb. I know of another, not dissimilar issue recently and after a week of searching it was tracked down to a bad connection with an under bonnet plug. Plug fixed, no more problem.