Peugeot 307 light flicker

[Pasty PFC]

Hi all,

I have a Peugeot 307 SW HDi from 2007. Over the last year it has developed an issue where the headlights intermittently flicker off. It's becoming dangerous now so I thought I better look into it.

When it happens the dash lights also turn off. Previously the duration was like a quick flicker, you could almost convince yourself that you might have blinked a little longer than normal. Lately though it's become more frequent and in a couple of cases all lights have turned off for around 5 seconds.

I expect it is a bad earth somewhere or maybe the stem switch.

Has anyone had a similar experience? I thought I would ask before I start attacking it.

Maybe someone knows of an earthing point which is prone to cause headlight issues?

Thanks.

[GiveMeABreak]

Hi and welcome to the Forum.

Yes, this sounds very much like a Comms 2000 unit fault. It is the control module that holds all the stalks in for your indicators and lights. These are known to develop problems with the lights and electrics. Sometimes the lights will come on and off on their own; other symptoms include loss of electrical systems power while driving (all lights on dash will go off and may come on again).

Best thing is to check the obvious first though - like fuses and bulbs, and to make sure there are no short circuits in the lighting system wiring. Because the faults are intermittent, it rarely causes a fault to be logged in Diagbox / Peugeot Planet 2000, but typically it means the unit is on its way out. Some can be repaired if you have the time and can be without the car for a while, but there are suppliers of new units that can be had quite reasonably compared to a brand new one from the dealer. I wouldn't recommend a second hand one, as you have now idea how old it is and may end up with similar issues.

[Pasty PFC]

Thanks for the reply, very helpful.

How easy is it to remove the Comms unit? Do I need special tools? I'm handy and have the usual set of torx bits. Would you recommend buying the complete unit or can I get way with the stem unit?

[GiveMeABreak]

You need a matching unit, which includes the indicator/lighting and wiper stalks, but you retain your own Cruise Control / Audio stalks (depending on year / model and whether these are separate or not).
It can be a bit tricky, as you'll need to disconnect the steering airbag module and if you have ESP on your system, will need to be very careful with the steering wheel angle sensor that is contained in the steering wheel unit too. We could of bought a new unit and fitted it - but when we considered that it would only save us about £90 from the main dealer price, we decided to get the part and have it fitted by our local Citroen dealer. For 2 reasons mainly - one the unit would need to go back if there was an issue, rendering the car inoperable for a period of time and secondly, I didn't have to worry about the fiddly work!

Here's a link we were going to buy ours from:
http://www.peugeotpartsforsale.com/peug ... 2000-units

You'll just need someone here on the Peugeot section with access to Peugeot parts to confirm you exact model via your VIN (as I only have access to Citroen parts) in case you are feeling adventurous and decide to give it a go.

[Pasty PFC]

Ok, thanks again, good advice. I'll give it some more thought.

[Barbaren]

Ok, thanks again, good advice. I'll give it some more thought.

I would put my money on a bad generator.

[GiveMeABreak]

Ok, thanks again, good advice. I'll give it some more thought.

Just make sure you rule out the obvious and less expensive things first - short circuits - loose / failing fuse before you embark on replacing the unit. Our C3 had a slightly wobbly indicator stalk too that was an issue - our main beams kept going from dipped to main and off randomly, plus the auto lights would just shut off and would constantly come on and off on their own during the day (on-coming drivers would be waving as if we had flashed them)! So all these issues pointed to the comms unit. All stopped once this was replaced. Are you experiencing any of the other issues associated with this, like indicators not cancelling, faulty horn, etc?

In the interim, here's a link to the C3 Owners Forum, that gives a tear down on some of the comms units - be aware though that there are a LOT of different models and several manufacturers - so they won't all be the same - but will give you an idea of some of the issues.
https://citroenc3owners.com/citroen-c3- ... -t467.html

Given that you have said the lights actually switch off with dashboard lights too - that is indicative of a comms unit -I had this happen on my Mark I C5 to - everything went off in the cabin - all healights, dashlights and display - the lot, then came on again - very unnerving! Again, it was a faulty comms 2000 unit that was replaced under warranty at the time.

[ekjdm14]

Ok, thanks again, good advice. I'll give it some more thought.

I would put my money on a bad generator.

Based on reading just the thread title, that would have been something I'd have suggested too.

However, on reading the details of the symptoms in the post (the lights actually switching fully off for up to 5 seconds etc) I'd have to agree it's likely the Comm 2000 at fault providing all fuses/wiring are sound.

[Barbaren]

Ok, thanks again, good advice. I'll give it some more thought.

I would put my money on a bad generator.

Based on reading just the thread title, that would have been something I'd have suggested too.

However, on reading the details of the symptoms in the post (the lights actually switching fully off for up to 5 seconds etc) I'd have to agree it's likely the Comm 2000 at fault providing all fuses/wiring are sound.

Talked to my GURU today. He is a French car Magician. He suggest that you try to reset the BSI. Using this method.
http://www.bba-reman.com/gb/content/peu ... ot_process

[RichardW]

I'm inclined to disagree with Marc....

An 07 307 will be a later full VAN bus version, and this uses a later version of the stalks, which is known as a COM2005 I think. Problems with these seem to be much less prevalent. Given that the dash lights go out as well, I'd be inclined to have a look at the underbonnet fuse box, and particularly the +ve connection to it, and also the BSI. A Lexia session might reveal something; eg repeated unexpected BSI resets or similar. There might also be an earth on or around the steering column somewhere.

[GiveMeABreak]

Good advice, as I said, try the simpler things first.
@Richard - I just use the term Comms 2000 interchangeably to mean all variations - the one we had done in the 2007 C3 was a different model again - there are loads, made by several manufacturers and have different designs. The fault is common amongst most of them - I've had 3 brand new ones (C5 MkI, C5 MkII and the C3) from 2001 to 2007 and the faults were cured each time. On neither of the occasions did Lexia show up any fault...

[RichardW]

I've had 3 brand new ones (C5 MkI, C5 MkII and the C3) from 2001 to 2007 and the faults were cured each time.

All of which are CAN bus AFAIK, and variants (as you say) of the COM2000. The facelift 307 is VAN bus, and uses a COM 2005 which is a different beast. Problems are rarer, but I did find some headlight problems reported on 308s. Mine 'forgets' to switch the lights off if you turn them off too quickly - but this seems to be a feature!

[Pasty PFC]

I have reset the BSI twice in the last couple of weeks. It certainly solves the problem initially however after a few days it comes back.

Is there any advice on which earthing points to check? I have checked the one near the BSI unit on the wheel arch.

[Barbaren]

I was just thinking (it happens once in a while).
Maybe you should get your generator tested.

[Pasty PFC]

I have tested the alternator, it is fine. Battery is getting good charge and no voltage drop. Also checked all connections and soaked with acf50. Must be BSI unit or stem switch.