C5 HDi 2005 Power Steering

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birstall
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C5 HDi 2005 Power Steering

Post by birstall » 27 Apr 2015, 16:54

Hi All

I'm getting a power steering fault message flashing up briefly then disappearing again. Sometimes the STOP light comes on then disappears again.

It's happening randomly once or twice on some trips.

I had to replace the EGR valve last week and the message started after I got the car back from the mechanic.

It may have flashed on once before this when I hit a pot hole heavily a couple of weeks ago, but not sure this is related.

I suspect a faulty wiring connection somewhere.

I haven't noticed any problem with the steering itself, seems fine.
Has anybody come across this before or got any idea where I should start to look?

The cars just coming up to 105,000 miles.

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Lighty
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Re: C5 HDi 2005 Power Steering

Post by Lighty » 28 Apr 2015, 20:26

You don't say which C5 you own, but have had a problem with the MK11, where the front bumper has worn through the wiring going to the electric pump behind it.Remove front bumper & the problem area is obvious.

birstall
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Re: C5 HDi 2005 Power Steering

Post by birstall » 29 Apr 2015, 13:00

Lighty

Thanks for the tip. Yes it's a MkII. I'm going to drop the car in with my mechanic on Friday so will ask him to check this.

birstall
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Re: C5 HDi 2005 Power Steering

Post by birstall » 05 May 2015, 12:42

It appears to be an intermittent fault on the CAN bus. Noticed over the weekend that it was flashing on and off when we hit bumps over a two mile stretch of road, then went away and hasn't come back yet. I may have to drop in with an auto electrician.

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Re: C5 HDi 2005 Power Steering

Post by citronut » 05 May 2015, 13:22

did you not follow Lighty's offering yet????,

he has ooodles of knowledge and experience on modern car electricary

birstall
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Re: C5 HDi 2005 Power Steering

Post by birstall » 06 May 2015, 13:32

I didn't check this personally but I asked my mechanic to check, but said he couldn't find anything wrong with the wiring himself. I'll double check that he looked at this. The fault message suggests a problem on the data bus, i.e. the power steering computer not sending the correct information back to the main computer? Not sure of this, maybe you can help further. Anyway the steering seems fine when you're driving so it could just be that the information on what's going on with it is not getting back to the central computer. I have the car at an auto electrician today so hoping he can help. I'll report back here if we get anywhere.

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Stickyfinger
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Re: C5 HDi 2005 Power Steering

Post by Stickyfinger » 07 May 2015, 08:29

It Needs to be put on a Lexia, not a general code reader.......whatever they say they should use one to get anything accurate

birstall
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Re: C5 HDi 2005 Power Steering

Post by birstall » 07 May 2015, 15:49

Well the auto-electrician has looked at it and come up with "steering wheel angle sensor" as the fault and fixed it. Not completely convinced that this was the actual fault yet as it was intermittent. Will see if the fault stays away! Otherwise will have to look at myself as he's quoted me £200-300 to fix if it's not fixed already. After the battery went flat I did check the messages and got the following:

Fault caused by another ECU.

The power steering ECU is no longer communicating on the CAN

Temporary fault + IGN supply

Temp fault Steering wheel rotational speed information no signal.

Some of these may have been caused by the battery being flat. If the problem comes back I'll check the fault messages again and compare.

birstall
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Re: C5 HDi 2005 Power Steering

Post by birstall » 07 May 2015, 22:43

Well, as I anticipated the fault is still there. In fact it's about ten times worse now than when I took it in.
I'll have to check it myself at the weekend. I'll get some Lexia readings first and take it from there.
Error message is springing up when I go over any uneven surface on the road. Beep, flaming beep!
I'll try with the car stationary and the engine running, then shake various components to see if I can spring the error message and make it obvious whereabouts the fault lies. Going to try this at the weekend.

birstall
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Re: C5 HDi 2005 Power Steering

Post by birstall » 08 May 2015, 12:06

I've spoken to the mechanic again and it seems I've misunderstood.

I've been advised that, apparently this model doesn't have a separate pump for the power steering: it's all from the same hydraulic system as the suspension.
We're not getting any error messages on the suspension, so it seems that, in their opinion, it must be the steering wheel angle sensor that's the problem.
They tried to fix this, but actually made it worse, so it would seem that this could well be the problem.

The £200-300 they quoted is for replacing the sensor with a new one (from Citroen - daylight robbery! IMHO).
Anyone got a working second hand one stashed away anywhere that they're willing to part with?

My only other concern that it may be the data connection cable going back to the main ECU that is the fault - maybe the connection at the ECU?

I tried banging the steering wheel but this had no effect, whereas going over a bump did. I might try shaking the ECU a bit and see what happens.
I suppose I could also try taking the steering wheel off and rattling the sensor to see what happens.

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Re: C5 HDi 2005 Power Steering

Post by RichardW » 08 May 2015, 12:38

MK2 appears to have separate PAS pump - may be electric (but not the same as the suspension) - post up the last 8 digits of the VIN and I'll confirm. Steering angle sensor built into the COM2000. I don't think the angle sensor has got anything to do with the PAS - it's more to do with the ESP (but I could be wrong...!) - so I would be expecting to see an ESP fault (which would stay up till re-started) if it was faulty. I'd be double checking the wiring as per Lighty's note, and then thinking about the underbonnet fuse box and the wiring to/from it.

birstall
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Re: C5 HDi 2005 Power Steering

Post by birstall » 08 May 2015, 15:52

Thanks for the advice Richard.

I sometimes get an ESP fault if I stop the car on a slight incline up hill and it rests back slightly, but this has happened since I got the car a few years back. As you say the fault light clears after a restart.

I'm inclined to agree with you and Lighty that it may be the wiring somewhere so will do a bit of selective shaking of wires with the engine running and see if it beeps! I'll get back to you with the VIN number.

birstall
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Re: C5 HDi 2005 Power Steering

Post by birstall » 08 May 2015, 20:10

The last 8 digits of the VIN No are: 76697262

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Re: C5 HDi 2005 Power Steering

Post by RichardW » 08 May 2015, 21:23

Electric pump on yours. Fed off the LDS reservoir, but it's a separate pump.

birstall
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Re: C5 HDi 2005 Power Steering

Post by birstall » 08 May 2015, 21:37

OK thanks Richard. It looks like they haven't checked this properly at all.
Will have to do my own investigations tomorrow.