C5 rear wiper with a mind of its own.

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detheridge
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C5 rear wiper with a mind of its own.

Post by detheridge »

Hi again folks,
My Mk1 C5 estate has a bizarre symptom. As soon as I start the front wipers, the rear one starts off on intermittent mode, and continues even when the main wipers are off. It'll go to wash/wipe mode quite happily, but switching it back to '0' leaves it in intermittent mode. The only way to stop it is when the ignition is switched off. It'll also start if I press the right hand stalk to change the main display. Is this a wiring problem on the tailgate, or do I need a new control stalk?

Thanks in advance,

David.
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GiveMeABreak
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Re: C5 rear wiper with a mind of its own.

Post by GiveMeABreak »

The BSI controls these functions and Fuse F2 in the BSI.

Try the good old procedure first:

BSI Reset / Battery Disconnect / Reconnect Procedure
detheridge
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Re: C5 rear wiper with a mind of its own.

Post by detheridge »

Many thanks for this Marc - I'll give it a try and report back. The previous owner solved the problem by taking out the fuse!

David.
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Re: C5 rear wiper with a mind of its own.

Post by RichardW »

Sounds like a COM2000 failure to me....
detheridge
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Re: C5 rear wiper with a mind of its own.

Post by detheridge »

And a COM2000 is? (Scuse my ignorance on this)
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Re: C5 rear wiper with a mind of its own.

Post by Hell Razor5543 »

The COM2000 unit is the module that houses the various stalks (indicators and so on) and other items.
detheridge
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Re: C5 rear wiper with a mind of its own.

Post by detheridge »

Ah, I see - many thanks. That's obvious.
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Re: C5 rear wiper with a mind of its own.

Post by Hell Razor5543 »

I would go ahead with the BSi reset (as explained by Marc). If it is just a glitch this should help to clear it. However, if it is an actual fault the BSi reset won't clear it, but it will then tell you that a real fault exists, as opposed to a mere hiccup.
detheridge
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Re: C5 rear wiper with a mind of its own.

Post by detheridge »

Has anyone tried this?
Last edited by myglaren on 07 Jan 2020, 10:44, edited 1 time in total.
Reason: YouTube link
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Re: C5 rear wiper with a mind of its own.

Post by RichardW »

Sorry, that was rather flippant!

The stalks under the wheel are not actually switches any more, they just send a message to the BSI which then sends messages elsewhere to turn on the various accessories. Usually the COM2000 fault is the lights / indicators not working or being erratic. If you could get it on on Diagbox you could probably check whether the BSI is seeing the on/off message from the stalk.
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Re: C5 rear wiper with a mind of its own.

Post by GiveMeABreak »

The later modules also handle the immobiliser handshaking requests from the BSI and a lot more things.

These modules can vary considerable depending on the vehicle, the electrical architecture and the options fitted - so be wary of youtube videos as they are not all the same modules / and not all can be repaired.

Earlier models where the stalks wore the contacts could sometimes be repaired - others not so easily.

I've replaced the unit in our C3 a year ago as it thought it was in a disco, obviously - with the auto lights flashing drivers at random times and the lights going off at night....

I also had one replaced in my MK I C5 as that caused a power cut off on the motorway! Lost all electrics on the dash, radio, heating etc., then it came back on again - so was a bit worrying - diagnosed as the Comms unit and that was replaced.
detheridge
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Re: C5 rear wiper with a mind of its own.

Post by detheridge »

Success!
It turned out to be the COM2000 unit after all. Searching around for prices was interesting, with official Cit prices well over £300, and someone on Ebay in Europe wanting no less than £466!

I got lucky with www.peugeotpartsforsale.com (usual disclaimer) who do recon units for £140 exchange, and the guy there is very helpful if you're thinking that you will need a similar unit.

Thanks for all the info and advice folks,
David.
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Re: C5 rear wiper with a mind of its own.

Post by Hell Razor5543 »

Good news, and well done.
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Re: C5 rear wiper with a mind of its own.

Post by GiveMeABreak »

detheridge wrote:
13 Jan 2020, 14:03
Success!
It turned out to be the COM2000 unit after all. Searching around for prices was interesting, with official Cit prices well over £300, and someone on Ebay in Europe wanting no less than £466!

I got lucky with www.peugeotpartsforsale.com (usual disclaimer) who do recon units for £140 exchange, and the guy there is very helpful if you're thinking that you will need a similar unit.

Thanks for all the info and advice folks,
David.
They're the people I recommend for new or reconditioned units. Glad you have it sorted now.