c5 2.2 HDi 173

[cachaciero]

That would suggest a pretty comprehensive failure of every CAN bus on the car OR a failure of the BSI / BHM doubt the original problem was due to the headlights they are on a separate LIN bus, If there is a pemanent failure of the BHM +ign relay why does the engine run? rhetorical question.

carioca

[mooseshaver]

I could email you the screen grabs of the lexia faults.
They all seem to be complaining about engine information not being there, and the steeringwheel angle sensor.
But with the esp fault on I could see the headlights moving as I slowly moved along with the wheel turned, then retuning to normal once stopped, then move again as I moved. They were reflecting off a car, I was inside the car driving.

[cachaciero]

Well lack of steering wheel sensor data will automatically cause the ESP system to fail. Steering wheel angle data comes via the main CAN bus to the ESP ECU similarly Steering wheel data (the same data) is sent on the same CAN bus to the headlight ECU which turns it into LIN data to send to the headlights. Now if you consistently have the headlights working well but an ESP failure with a steering angle fault it would suggest a "hole" in the CAN bus, can't be more specific as I havent yet found a diagram which shows me the physical layout of the bus. Given that many of the other other messages the Lexia has come up with are saying effectively outright comms failure, presumably intermittently, I come back to the point that every ECU on the CAN bus needs to be disconnected and the wires checked for both continuity, shorts to ground and too each other preferably with a tester that can put several hundred volts on the cables like a megger. WARNING If anybody follows this advise be sure, absolutely sure that every electronic device is disconnected and the free connectors are as far away from their mating halves as possible.

cachaciero

[mooseshaver]

Nothing new, the Dealer is looking at the wiring. I thought they spent the previous 5 weeks doing that.

[cachaciero]

Is this with a pukka Citroen dealer (who should have all the breakout cables as well as a Lexia) or is with joe bloggs who probably hasn't got either?
Because another less invasive test I would do with the gear is to break-out the can bus connector to the ESP ECU and look at the signals with a scope.

EDIT Answer, for those that read the question.. was don't confuse C4 with C5.

cachaciero

[mooseshaver]

It's a main Citroen dealer.
I don't really know what they are doing.

[cachaciero]

Does'nt sound like they do either

[mooseshaver]

Does'nt sound like they do either

No, not really. They are still checking the wiring, I've asked about the Citroen person coming out and they have said thats the next step but Citroen want them to do these checks first, so that a bit of hope.

[mooseshaver]

I have been told that Citroen technical have seen this before and believe its a fault in the can bus loom.
So they are looking at all the wiring for a dry joint, water or broken wire.
Pleased there is something to aim for as Citroen think they know.

[Xantidote]

Lucky it's not you having to troubleshoot & sort the problem

[mooseshaver]

I know. The place I bought it from have been great and sorting paying for it.
I just wish I had it now working.
How many KMs of wire is there ? 3?
Shouldn't take too long

[cachaciero]

I have been told that Citroen technical have seen this before and believe its a fault in the can bus loom.
So they are looking at all the wiring for a dry joint, water or broken wire.
Pleased there is something to aim for as Citroen think they know.

Er.... isn't that what myself and lightly been saying for a while now? and by looking at what works properly and wot doesn't should be easy to narrow the area down.

cachaciero

[mooseshaver]

Yeah, it is what you have both been saying. And it has been suggested and passed onto the dealer.
Perhaps they don't like it when others suggest things. They did say they have got the bumper off. I did not reply "that's the second time"

[mooseshaver]

Ok today I find that the Dealer can't fix it and the problem has progressed to Citroen France who will either tell them how to fix it or send a diagnostic tech.
I really hope they do something soon and that they fix it. It will 7 weeks of stress tomorrow.

The problem was with France yesterday at 2pm and they have do far heard nothing back.

[civvie]

The problem was with France yesterday at 2pm and they have do far heard nothing back.

France goes on holiday during August