C5 - Suspension stuck on maximum height

[kettlesimon]

Following a recent failure of the suspension pump motor, the mechanic has fitted a secondhand pump and ECU. The first ECU would allow the suspension to rise and fall, but would not switch off the pump. A replacement ECU has now been fitted, which does switch off, but now the suspension is stuck on maximm height and wont come back down. The mechanic thinks that it might need recalibrating with the Lexia equipment. Can anyone comment if they have had a similar problem. He suggests driving the car to a specialist with the Lexia gear, but is it safe to drive on maximum height. HELP

[Ben82]

You can drive, but the max speed is 10km/h or 6mph. You could try slightly exceeding that speed to see if the car will bring it down itself, but I wouldn't recommend driving above that speed for an extended period of time if it doesn't lower itself.

Might be worth seeing if there's any members nearby with a lexia, list here: http://www.frenchcarforum.co.uk/forum/v ... 19&t=29178" onclick="window.open(this.href);return false; they might be willing to come to you instead with the lexia for taking a look.

[1275jstrap]

Setting the heights on any citroen with hydrocactive sespension the citroen way is a royal pain in the ass it includes a set of calcuations even the cleverest gimp could not even calculate. as a practice we at out specialist only ever replace the pump motor as that is all that ever goes wrong. i can get you the calculations if you need but beware they are a nightmare. have tou still got your origanal ecu???

[kettlesimon]

Hi thanks for that i will check with the garage re the original ECU. They are shut now till monday.

[kettlesimon]

Any other ideas anyone on this problem. Got to get it sorted as the car is vital to my business

[Hell Razor5543]

It is known that the C5 (and other C Citroens) can throw weird wobblies. Something that can help is to (in effect) reset the ECUs to clear them down. It doesn't always work, but it has got to be worth a try. If it doesn't, pop the original ECU back on and have another go.

http://www.frenchcarforum.co.uk/forum/v ... 11&t=40407" onclick="window.open(this.href);return false;

I hope this helps.

[Citroenmad]

I went over to see Simon and his C5 today to see if I could shed any light on this with the Lexia, here is our findings:

These are the fault codes stored in the suspension ECU:


The top code opens with:

Note the sensor power supply: Missing

All codes could be deleted however the first two restore on start up.

The front and rear electrovalve operations are not controlable with the Lexia, they should be.

The front could be lowered with the lexia but would not pump back up. The rear only dropped slightly when asked by the Lexia to lower. After a while the suspension pump came to life and restored the car to full height again, but the pump could not be operated with the Lexia and did not function again after going back to high.

The car does not react at all to the interior suspension level button, it just keeps flashing up the high level and 6mph speed restriction.

It would seem to me that the open circuit fault is a result of wiring or potentially a faulty electrovalve, but not for them both to not function?

The wiring loom to the suspension ECU has been taken from another car, the garage claim that car had more "suspesion spec" so I asume its from a fully hydractive + C5. The garage then patched the wires to this new loon/plug to plug into the ECU. However, there are at least four wires which are not connected and are simply snipped at the plug. While this might appear to be the fault, is it?
Does a H3+ have more wiring to the ECU?
I wonder if the ECU could be from a H3+?
Does anyone know of a wiring diagram for this plug?

The first ECU apparently kept the pump running (probably the cause of the fire) but after the new wiring it could reach all suspension levels and was working fine ... im not sure, if it is a wiring fault ... . The ECU which is fitted now apparently did work until it raised to full height and wouldnt move.

The garage is confident it is wired in correctly but is it ...

Here is the plug, you can see the 'spare' 4 wires which are snipped off.


Has anyone got any ideas on this? Im thinking the wiring still needs work

[boristhespie]

Not sure this helps but ours stuck at full height once and it was the switch on the bottom of the car that needed fixed. Cheap and quick. May be worth checking. ??