Fault U1208

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Mikes
Posts: 6
Joined: 10 Feb 2020, 11:33

Fault U1208

Post by Mikes »

Good morning,
I have a citroen 2007 c4 picasso grand. After 1 year I got it, a fault U1208 appeared.
And after 4 days it appeared faulty handbrake, esp and service.
The first thing I checked was the battery and it's ok.
I went to the garage with a maxisys diagnostic tool where he tried to delete the fault but it came up again.We checked the four sensors on the wheels and its working. We checked the 'plugs' of the abs, ECU under the Bonnet (not the handbreak one). Everything looks fine. The handbreak is working. But the fault is still up.
Any ideas regarding that? Any help would be great. Thanks
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26087
Joined: 15 Sep 2015, 19:38
x 3000

Re: Fault U1208

Post by GiveMeABreak »

Hi and welcome.

That fault code means there is no communication between the ESP ECU and the Engine Management ECU.

Whilst active, all the ESP functions are deactivated including Hill Start Assist etc. Basically it is not detecting any information being sent by the engine ECU. The SERVICE warning lamp will be lit, as will the ESP / ASR lamp.

The suspect areas are: Connectors, CAN network, ESP ECU. So first thing is to check the actual wiring connectors. Has any work been done recently on the vehicle?
Mikes
Posts: 6
Joined: 10 Feb 2020, 11:33

Re: Fault U1208

Post by Mikes »

Hi Marc,
No there hasn't been done any work at the vehicle at the moment.
Can you please give me a bit more explanation regarding the wiring connectors?
Thanks
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26087
Joined: 15 Sep 2015, 19:38
x 3000

Re: Fault U1208

Post by GiveMeABreak »

Just eliminate the obvious - the vehicle ECUs talk to each other via various multiplexed data networks. Somewhere along the line there is a communication disruption - so it would seem the first and easiest places to check are the physical connections on the ESP ECU and the Engine ECU.

It's also not unknown on the C4 Picassos for the wiring to break in the looms (they have far too many wires in a thick bundle that puts stress on the wiring and can cause breaks and shorts), but that requires fault finding.

If you post up your VIN (automatically masked from public view) I can dig out a wiring diagram for your specific C4P. I can point you in the right direction for likely connections to check.
Mikes
Posts: 6
Joined: 10 Feb 2020, 11:33

Re: Fault U1208

Post by Mikes »

Thanks so much.
The Vin is VF7**************[VIN obfuscated, can be read by forum staff]
Last edited by GiveMeABreak on 10 Feb 2020, 12:46, edited 1 time in total.
Reason: Corrected VIN
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26087
Joined: 15 Sep 2015, 19:38
x 3000

Re: Fault U1208

Post by GiveMeABreak »

Ok, so here is the Injection ECU wiring as it shows the main CAN connections to the ESP ECU and from the ESP ECU to the BSI.

Additional hardware codes can be fouind here in ascending order on our Wiki:

PSA Electrical Codes

1320 is the injection ECU
7800 is the ESP ECU

CAN Wiring Injection ECU:
9010 : High Intersystem 2 Can bus
9011 : Low Intersystem 2 Can bus

CAN Wiring ESP to BSI:
9000 : High Intersystem / Can bus
9001 : Low Intersystem / Can bus

Injection Wiring C4 Picasso 110 FAP DV6TED4)

Image

Location

Image
Mikes
Posts: 6
Joined: 10 Feb 2020, 11:33

Re: Fault U1208

Post by Mikes »

Thank you very much for your help! I really appreciate it.
Mikes
Posts: 6
Joined: 10 Feb 2020, 11:33

Re: Fault U1208

Post by Mikes »

Can you on some way send me these pictures in a file? So that I can download and print them?
User avatar
GiveMeABreak
Forum Admin Team
Posts: 26087
Joined: 15 Sep 2015, 19:38
x 3000

Re: Fault U1208

Post by GiveMeABreak »

Unfortunately not. These are SVG (vector graphics), so will scale perfectly to any size. This enables people with mobiles, or PCs to be able to view them and zoom them up without losing definition. However most browsers can display SVG files - so if you right click the image you want, then choose 'save image as', then save to your PC, you should then be able to double click the image and select your browser to view it. You can then print it from your browser.
Mikes
Posts: 6
Joined: 10 Feb 2020, 11:33

Re: Fault U1208

Post by Mikes »

Yes you are right. I was trying to do it with my mobile that's why I couldn't print it. I used the pc and ot is printed out perfectly. Thanks again.
RichardW
Forum Treasurer
Posts: 9655
Joined: 07 Aug 2002, 17:12
x 494

Re: Fault U1208

Post by RichardW »

Re-scan it and see if there are any EGR faults. These don't necessarily put the engine management light on, but can cause the brake warning to come on. Been there, chased it for 9 months....