Citroen C4 Grand Picasso ABS, ESP, Hill Hold

[XIIIESA]

Good Morning,

Trying my luck on here before I lose the will to live completely, my Citroen has started displaying all sorts of esp/abs related codes on start up out of nowhere, I’ve plugged my MaxiSys Pro in and found the following faults.

C1391:00 Fault, engine torque not cleared
C003A:11 Rear right wheel speed sensor - short circuit to ground.

I’ve replaced both my wheel speed sensor and bearing on the rear right but still had no luck which points me to believing it is wiring related. Unfortunately I’m on a tight timeframe as I’m leaving for a Europe trip on Saturday and all auto electricians have at least a 2 week lead time where I am, everyone is really busy so I’m having to try this myself.

I’ve checked the voltage supply on the wheel speed sensor plugs using a multimeter, all are showing 12 volts on ignition apart from the rear right which is showing me 8v, leading me to believe there’s a corroded/abraded wire in the loom somewhere. Is there anywhere specific I should be focusing my efforts on?

I’ve had a look at whatever diagrams I can find online and they all show the wiring seems to split off under the rear seats, is my break likely to be somewhere between there and the wheel? Or am I totally wrong.

Really pulling my hair out on this, thanks in advance to everyone who helps. I will keep you all updated through the process and hopefully it can help someone else further down the line too.

Thank you

[GiveMeABreak]

Pop your VIN up so I can see if I can get you a wiring diagram. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

[XIIIESA]

Thanks for this,

VIN: VF7**************[VIN obfuscated, can be read by forum staff]

[GiveMeABreak]

Here's the diagram:

Note that whilst you have any issues with a wheel speed sensor, it will deactivate most features of the system, including ESP, Hill Start Assist, cruise control etc.

7825 is the rear Right Hand Wheel Speed Sensor.

Most other electrical codes are here:

viewtopic.php?t=80489

Now it's a known issue with the wiring on these that the insulation can crack causing a short. Have a look at my other post on this here that goes into the checks:

viewtopic.php?p=660516#p660516




Here's the wiring schematic:

[XIIIESA]

Thanks for that, let me have a look and see if I have any luck, going to start with the cabling closest to the fuel tank on rear drivers side as they’re an apparent weak point. Will keep this post updated in the hope it helps anybody else who experiences these issues in the future.

[XIIIESA]

Turns out I have 3 potential points of corrosion on the yellow wire. Have passed through with another wire, cleared the codes and started the car and the errors haven’t returned. Will patch it up properly, put the wheel back on and take it for a drive, fingers crossed that’s the end of it…

[GiveMeABreak]

Ok good luck, but your image is blank, so I've deleted it