Headlight stays on

[zeeshanzaki]

I have very weird issue with Citroen c5. The headlight does not turn off if switch off the car. Initially I thought its automatic light causing the problem, but I switched off this feature. As a workaround, I disconnect the fuse box under the bonnet, disconnect all the connector and remove it. leave it for 30 min and reconnect it to make it working. It works for few days and start playing up again. What I noticed last time when this issue appears, the power seat had power even though I removed the key from the car. So it look like the car receives to battery power which might causing this issue.

Can someone point me to right direction to fix this problem?

[GiveMeABreak]

Hi and welcome to the Forum.

You will usually have about 30 seconds of power for equipment like electric windows / seats once you remove the key from the ignition (depending on battery condition).
Are you sure you don't have the 'Guide Me Home' lighting option activated? - if so the headlamps will stay on for a pre-determined time after you leave the vehicle.
What Model, year / trim is it or better still, what is the VIN, so we know what you have?

[zeeshanzaki]

Hi Marc
It is Citroen C5 v6 2001.
Its more than 30 seconds after removing the key. I only noticed the power in headlight and seat. The headlights remains on and it drains the battery last time, so its not Guide Me Home option. Since I bought this car I noticed that 12v socket always has power even though car is locked but never had headlight issue.

[GiveMeABreak]

It sounds on the face of it like the Comms 2000 unit. Is the lighting stalk loose - does it wobble slightly? If the unit is faulty, some of the common issues are headlights coming on and off on their own - regardless of lighting conditions, indicators coming on / not cancelling. The trouble with the comms units is that they don't always show or store a fault that can be read with a lexia.

Check all the relays and fuses for the lighting circuit first. If you do need a replacement comms unit, you will need to recalibrate the steering wheel angle sensor as your car will have ESP. Once the comms unit is removed / replaced this will need resetting, otherwise you will get ABS / ESP faults and the system will be inoperative.

If you are looking for some help in your neck of the woods, try http://www.aussiefrogs.com/ who may have someone that can help you with a diagnosis more locally.

[myglaren]

The seat power stays on a while - haven't checked how long but comes back on if you open a door, no need to start the car.
The driver's seat stays powered for ages if you sit in it, again haven't checked a time but I would estimate about half an hour.

[zeeshanzaki]

If there is issue with comms2000 then it should stay after reconnecting all conectors. If it is too expensive to fix coms 200 then i would better to put some manual switch to switch off headlights.

I tried locating headlights relay but couldn't find it. I can hear tick sound when turning on headlighy ftom glowbox.

[BX]

This fault is usually caused by a sticky relay in the BSM, the engine bay fuse box. The relays are industry standard and are soldered to the PCB. The whole BSM unit can be just swapped out for a replacement, new or second hand. They are not programmed.

[zeeshanzaki]

When I turned off the headlight the instruments lights switch off but headlight stays on.

[zeeshanzaki]

This fault is usually caused by a sticky relay in the BSM, the engine bay fuse box. The relays are industry standard and are soldered to the PCB. The whole BSM unit can be just swapped out for a replacement, new or second hand. They are not programmed.

I removed the fuse box out of the car and removed its onside plastic cover to find out where the relay is but the top cover is glued with PCB and hard to remove. I also found similar solution on ( http://www.citroen-owners-club.co.uk/ci ... t-working/ ). The fuse box is very thin to accommodate any relays on it, most of the PCB coverd with fuses and there is hardly any space for relays.

[BX]

Correct. Your steering column switch (often mistakenly referred to as the comms unit) is sending the correct signal to the BSI. The dash lights are extinguished. The signal to release the headlamps relay is sent to the BSM. however the relay contacts remain stuck closed. There are separate relays for main beam and dips. Sometimes tapping the engine bay fuse box gets it to release. I have changed several of these relays on berlingo, c5, c4, Peugeot 307. There is one particular Siemens box where you cannot do the repair as the whole unit is potted in some sort of silicon rubber. Delphi and Valeo boxes can usually be easily repaired. The relays are available from sources uch as Farnell or RS Components.

http://ie.rs-online.com/web/p/non-latch ... s/2172876/

This might not be the actual one used in your unit but it serves as an example

[GiveMeABreak]

Whether referred to as the Comms unit or the 'switch module under the steering wheel' as PSA refer to it in the technical documents, it is the unit that houses the lighting, indicator, cruise and audio stalks.

Sometimes the faults can be the contacts between the stalk and the Comms unit PCB and can be repaired (there are many types). Sometimes the whole unit has to be replaced. We have replaced them on C5s and the C3 for issues relating to complete dash lighting electrical cut out, flickering lights, switching on main beam / dipped beam randomly and switching them off, and other niggles with indicator lights. Also the headlights can also come on with the engine off and the car locked. I'm not saying this is related to the same issue you are having, but it might be a possible cause if you have tried everything else!

[BX]

I agree with Marc. The steering column switch unit can and does cause all of the above. I have tried, with varying levels of success, to repair several of them. The easiest repair is the ribbon cable for the horn and the airbag igniter.

[zeeshanzaki]

I agree with Marc. The steering column switch unit can and does cause all of the above. I have tried, with varying levels of success, to repair several of them. The easiest repair is the ribbon cable for the horn and the airbag igniter.

Can it be repair without removing steering wheel?

[GiveMeABreak]

No, it needs to come off, along with the steering wheel airbag module and connectors, so you should ensure that the battery is disconnected and and the car has been left for 10 minutes to discharge the air bag systems before working on it. Once you do this you will have to be very careful with the clock spring / ribbon cable reel / steering wheel angle sensor assembly. As I said earlier you will likely have ESP on your V6 so will have to get the steering wheel angle sensor recalibrated after with a Lexia.

Before you consider any of this, I would strongly suggest that you have the car diagnosed properly with a Lexia to identify any faults that may be causing the problem BEFORE replacing any parts. That will avoid any unnecessary expense.

If it is found to be a Switch Module fault, post up your VIN and I'll be able to identify the correct replacement for your specific vehicle. If you don't have the equipment or expertise to replace this yourself, it might be worth sourcing a replacement and getting an experienced garage to replace it for you.

[zeeshanzaki]

No, it needs to come off, along with the steering wheel airbag module and connectors, so you should ensure that the battery is disconnected and and the car has been left for 10 minutes to discharge the air bag systems before working on it. Once you do this you will have to be very careful with the clock spring / ribbon cable reel / steering wheel angle sensor assembly. As I said earlier you will likely have ESP on your V6 so will have to get the steering wheel angle sensor recalibrated after with a Lexia.

Before you consider any of this, I would strongly suggest that you have the car diagnosed properly with a Lexia to identify any faults that may be causing the problem BEFORE replacing any parts. That will avoid any unnecessary expense.

If it is found to be a Switch Module fault, post up your VIN and I'll be able to identify the correct replacement for your specific vehicle. If you don't have the equipment or expertise to replace this yourself, it might be worth sourcing a replacement and getting an experienced garage to replace it for you.

Hi Marc
Thank you for your suggestion.
At the moment looks like removing both battery cable resolves the issue for few days. I might try replacing relay if I have another car standby in case it become damaged.