C5 X7 2.0 HDI, AISIN AM6, GEARBOX FOULTY message, WON'T START

[mirel007]

Hi all, hope you all are better than I am ... I have a big problem (the wife is normally using the car,)... and I really, really hope you can help me ...
Citroen C5 x7 2.0 hdi 2009 with AISIN AM6 gearbox. I changed the tires from winter to summer in the front (I disconnected the + before doing the change), then I started the engine and moved the position of the car.
When I pulled the shifter out of P it gave a serious jolt, it was not the first time; I change the rear, again with the + disconnected, and when I was done, I reconnected the + terminal, and ... when I turned the ignition key:
GearBox Faulty, DS3, Intermittent S and snow, SERVICE lights up, Electric Secondary Brake Faulty and the ENGINE WOULD NOT START !!!.... I disconnected the battery for several hours, nothing.
Sometimes I see the box P, 1, 6, D3 in the display, but the engine does not want to start .... A RESET procedure for the box ??? The message U1108 - CAN communication error with the BSM. CONVERTER STATUS - no BYPASS and not OPEN. - permanent error
VIN number, just in case:
VF7**************[VIN obfuscated, can be read by forum staff]

There are several errore codes:

BVA AM6:
U1108

ABS/ASR:
U1108
U1308
U2119

ESF:
U1108

PRESSURE SENSOR
U1108
U1213

CORNERING LIGHTS
U1108
U1208

Some of them can be deleted but not the one on the BVA AM6; for now the car is at a mechanic, but he hasn't found anything for 4 days ... I think he's not really interested in working to find the error; he already informed me that I have to pay 3000,- dkk (400,- Euro) for the time he put in, and I told him not to touch the car anymore.
I will get it back to my place and I would try to see if there is anything that I can maybe find ... so any advice/idea no matter how small would be deeply appreciated. (I also have some pictures and a small video with the BSM where a relay is clicking when the contact/ignition is on. (the BSM was changed with a brand new one, and there was no change)

Thanks all in advance, Mirel.
(Sorry if the message is too long)

[GiveMeABreak]

The user contact form is only for logging in or other user issues, not for posting technical issues - I have now moved your post to the Citroen Forum.

[mirel007]

thanks Marc, it is my first post and I realised I made that mistake only after I pressed the SUBMIT button.
I will not make the same mistake again ...

[GiveMeABreak]

To be honest and I know it's not much help now, but I'd have taken it to the dealer who could of diagnosed it for a lot less and probably given you the cause.

There is a technical document that details issues if codes P0928, U1108, U1308 are present, but you don't seem to have the P0928. But this is only where the gear selector won't release from the P position (Shift Lock Jamming).

When the gearbox goes into backup mode it gives you third gear only in forward. Advice is to check Fuse F1 in the engine Fuse box - which I see you have changed the entire box already. The recommendation is only to change the fuse box if fuse F1 has not blown and P0215 and P0245 faults are present - which again they are not in your case.

A lot of the faults would seem to be communications faults - and a lot of the systems are inter-related, so a fault in one system will throw up faults with the other systems, so be aware of this - hence the need to focus un the gearbox / gearbox ECU connections first. It may be that the hydraulic block has failed - but again only guesswork, so really needs specialist attention.

At this stage and because guided diagnostics are required, I would cut your losses and get it to Citroen themselves who know the vehicle and have the appropriate technical systems to diagnose the faults correctly, or it may cost you money for being none the wiser as you have found out.