C5 hdi vtr 55reg suspension problem

[Bob Warwick]

One morning screen flashed up do not exceed 55mph suspension fault. The pump had not come on therefore over the next couple of days the car slowly 'sat down'. There is a garage a couple of miles from home that put it on their diagnostic machine a d informed me there were 5 electrical faults on the car (one being the speaker in the drivers door) and suggested I take it to Citroen.
Is there anyone in the Hereford area who can help me with this one.
Bob

[GiveMeABreak]

It’s possible your LDS pump has had some fluid leaking (spills) down the side and onto the pump motor housing and may have seeped in, causing the brush material to mix with the oil and cause a short. This will likely blow the pump fuse.

The fault codes would help if you have them to start with along with your VIN so we can identify exactly the vehicle you have.

[Bob Warwick]

Diagnostic report
C1141 Permanent body sensor front
C1147 Permanent body sensor rear
U113 Temporary NO COM ABS ECU
U118 Temporary NO COM SYSTEMS INTERFACE
U1205 Permanent NO COM STEERING WHEEL ANGLE SENSOR (incorrect value)
U118 Temp fault - refer to manual
U2005 Temp fault - refer to manual
Vin VF7**************[VIN obfuscated, can be read by forum staff]
Thanks Bob

[GiveMeABreak]

Bob, thanks for the detailed info. I will look at this in the morning for you and put something up.

[GiveMeABreak]

Hi Bob, unfortunately there is little further information on those codes.

U1118: Fault absence of communication with the built-in systems interface: No signal
U1113: Fault: absence of communication with the ABS ECU: No signal
C1141: Front body height sensor fault
C1147: Rear body height sensor fault : Open circuit or short circuit to earth
U1205: Fault: absence of communication with the steering wheel angle sensor: Value received incorrect

So to put it into some context, ignore U2005 for a moment - that is a standard fault code returned when the suspension ECU is interrogated with diagnostic equipment.

The Steering Wheel Angle Sensor is integral to the ESP system and this appears to be a communication fault with the ABS/ESP ECU - and doesn't necessarily mean there is anything wrong with it.

As for the suspension issues - the height correctors are analogue potentiometer devices that send the positional height information of the front and rear of the vehicle to the suspension ECU. It is unlikely for both these to fail at the same time, so again, I think this is a communication issue somewhere.

So what do all these have in common - well the the ESP ECU is linked to the suspension ECU via the CAN bus; the height correctors are linked to the Suspension ECU via analogue connections; and the Suspension ECU is linked to the BSI. So there is the connection.

So the first thing I would be asking, is have you had any work done in the engine bay / right hand wheel area of the car lately?
Has the BSI (or any of the fuses around the BSI in the passenger glovebox) been disturbed?

I would suggest that the connectors of the BHI (Suspension Control ECU) are checked to ensure they are secure or have not been dislodged, are loose or have been damaged / contaminated).

Secondly, I would check the ABS ECU for the same and make sure that the connections are all sound and that there is no damage to the wiring there - and ditto with the BSI as the first steps.

[Bob Warwick]

I changed the bulb in the headlamp in front of the suspension tank/pump 1 day before the fault showed up.

[Bob Warwick]

BSI Unit not touched. Excuse my ignorance but where is the BHI unit located?

[GiveMeABreak]

The BHI is underneath the LDS tank Bob. It is essentially the suspension pump and electronic interface, so if it was the driver side headlamp unit - there is a possibility of dislodging something there.

[olliewarwick1]

Just to interrupt this thread, but I'm Bob's son, as both of our rather original forum name's would suggest. I put the car onto Lexia yesterday and it would not initiate a dialogue with the suspension ECU through global test. When I clicked onto it anyway it just said that this system is an ECOTEC (or similar, I can't remember now) and still wouldn't communicate.

Dad has checked ad cleaned all of the connections to the BHI, therefore I don't think that's the issue.

Given that Lexia can't interrogate the sus ECU, would a replacement now be in order, if so what configuration is required?

Thanks,
Ollie

[GiveMeABreak]

The suspension system ECU on the MK I and MK II is referred to as Suspension ECO_TECH. This is correct - the ECU is incorporated into the BHI. If there is no communication it could be for various reasons - the VCI firmware may be too new (what version of Diagbox are you running?), or a faulty pin / connector on the diagnostic port / connection to the diagnostic port from the suspension ECU (I think I mentioned that in my earlier post).

Can you conform whether the manual suspension height control switch raises or lowers the car through all positions?
Are you still getting the suspension message concerning the max speed 55 mph?
When you connect your VCI are there any other ECUS on the Global test that show no communication?

PS: I've unmerged the threads now to keep these separate.

[olliewarwick1]

Hi Marc,
Thanks for sorting the threads, much easier to follow now. I will ask Dad to check to see if he gets the message still on the car concerning max speed 55mph. I will also ask him to check the manual switch, but I do know that he checked this before and it didn't work.
The lexia picked up all the other ECUs, just not the suspension one, although interestingly and not wanting to muddy the waters with the other thread, it didn't pick up the suspension ecu on his mk1 either. I will check my version of DIAGBOX, if it's easy to match the equivalent PP2000 version is 7.02.
Will come back to you, although it may take a little while as I live in Guildford, Dad is currently not well and he lives in Hereford.

[Bob Warwick]

Hi Marc,
Sorry for the long delay but I spent some days as a guest with the NHS. I have checked the response to the manual raise/lower buttons. The car is physically not moving at all, but the screen is registering that the buttons have been pressed. ie: lower, the screen car goes down and 5mph shows, raise, screen car goes up and OK registered. (The car does not move)

[Bob Warwick]

The "do not exceed 55mph no longer comes up, possibly because the car is sitting right down.

[GiveMeABreak]

Ok, so when you unlock the car in the morning and open the door do you hear the pump engaging or after starting the engine? It sounds like an electric motor. If it doesn't then the pump motor fuse may have blown.

It's Maxi Fuse MF8 (40Amp) for the hydraulic block motor.

[Bob Warwick]

The motor has made no attempt to start since the beginning of the problem