C5 spec & comms 2000 faults ?

[imperial21]

Hi
I have heard of the comms units failing and would like to know what faults they can produce ? I have noticed with my car that it can do a few strange things I am sure i saw the headlights come on on there own, Also the air bag light is on, Could it also cause the engine fault light to come on ? Also do all C5 have the fuel / trip computer ? My car when you tap the end of the wiper switch it switches the display to date but press it again and the rear wiper starts going !

[myglaren]

Hi
I have heard of the comms units failing and would like to know what faults they can produce ? I have noticed with my car that it can do a few strange things I am sure i saw the headlights come on on there own,

That will be your autolights operating. They should come on at dusk - about the time the street lighting comes on, but going through a tunnel will generally switch them on too.
The lights invariably come on after four sweeps of the wipers (it is law that you should use dipped headlights with falling rain or snow, fog and other conditions of reduced visibility). My estate got very random at putting the lights on and I was once stopped by the police who thought I was flashing the lights to attract their attention.

Also the air bag light is on, Could it also cause the engine fault light to come on ?

This can occur with reduced voltage, perhaps your battery is past it's best. Does it clear after a long run?

Also do all C5 have the fuel / trip computer ?

I don't think the LX has but everything of a higher trim level does

My car when you tap the end of the wiper switch it switches the display to date but press it again and the rear wiper starts going !

That does sound like a comms2000 fault but it could be the notoriously fragile springs in the button.

[imperial21]

Battery is brand new, i am still trying to get used to the c5, at the moment i prefer my old xantia ! pity i am scrapping that !!
Would my Lx spec car have auto light s ? I dont think it was dusk or anything when the lights came on, i turned the switch on / off lights went off !!!
Also i do get a few beeps when i first start the car ? !!

[myglaren]

I don't think the LX has autolights - look for a pair of sensors on the screen where the mirror base hides them from inside.
If there is one, it will be the light sensor as the LX won't have the rain sensor.

I put a new battery in mine but problems persisted.
First start every day and if the car was left for more than about eight hours would throw up airbag faults among other things.
I eventually credited it to a current drain but never discovered (actually never investigated) the source.
STOP light on. This is within seconds of being started from cold. I just ignore it and after a minute or so it goes away.

[imperial21]

Ah well i am sure there are nt any sensors on the screen ! I am taking the car down t my local garage on friday to have there computer put on it to see why the ngine light is on, fingers crossed its a cheap easily fixed fault !
Also would you say the C5 is little sluggish compared to the Xantia ? as my xantia and C5 are both 110 bhp hdi s but i think the xantia is nippier ? I gues the C5 is alot heavier ?

[xantia_v6]

at the moment i prefer my old xantia ! pity i am scrapping that !!

Not too late to change your mind is it? fix the Xantia and break the C5...

[myglaren]

Mine certainly are sluggish, with moments of brilliance.
The estate has been 'fixed up' and goes like the clappers now and my current one is due for some remedials once the MOT is out of the way.
They are generally regarded a sluggish but some seem to be exceptionally good. Very individual it seems.
My current one has been abysmal until a couple of weeks ago then decided to be quick. It sometimes forgets though.

Have you considered getting one of the members with a Lexia run a diagnostic for you?

Will be far less costly than a garage who won't be able to thoroughly interrogate your ECUs with a generic diagnostic machine.

Lexia Locations.

[imperial21]

I contacted MIKET as i think he is the only local one but have nt had answer yet, The garage will do it for a favour to me so should nt cost much, I suspected the C5 is just a bit heavy, I used to have a 406 HDI 110bhp and that was about the same as the C5, I was just interested though i didnt buy it for performance i am an economy driver, I watch the fuel gauge as much as the speedo !
At the moment i am preparing myself for a clutch change to make the car more comfortable to drive as the clutch pedal bites right at the top but at least its not slipping !

[Citroenmad]

Your LX won't have auto lights, so that sounds like a comms2000 problem. When do the lights come on? Are you operating the stalk for a different reason at the time?

I had one C5 which when indicating left, would do so three times, the indicator would then stop and the headlights would come on Driving with the sidelights turned on made it work perfectly though, I replaced the comms.

Steve is right, the LX does not have a trip computer, however you can fit one. Im pretty sure its just a matter of getting hold of a display to put in the centre dash. If your wiper is operated by pressing the end stalk button, I would say the comms2000 has developed a mind of its own and needs swapping out.

If you have an airbag fault, I guess you dont know where it is as I doubt your LX with the smaller centre screen will tell you which one it is, then that does light the 'Service' light as well as the airbag light. The most common problem are the connectors under the passenger side front footwell. Often a good cleaning with electrical contact cleaner and working in and out a few times cures that.

Performance, well that does seem to vary a great deal among the 2.0HDi 8vs. Ive driven a few which were painfully slow, had I not of driven quite a few 8v C5 HDis I would really question the methods of fitting a 90bhp to one. Others have been quite sprightly, really cant be called brisk as 110bhp in quite a large and heavy car is never going to be a ball of fire. They are adequate and provide some go. Ive not done any towing with one, which is when you would notice a lack in power, however fully loaded with 5 people, lots of luggage and three bikes, they still perform ok.... Well they should, but they do vary a lot, as I say. I find the MAF sensor has a lot to answer for, fit a cheap one and the car is ruined, as a friend is finding out with his 2.2HDi auto at the moment!

One of the slowest C5 110s ive driven was our old estate, it was very hard work and needed thrashing everywhere, giving very poor MPG. I owned our 110 SX saloon at the time, which was a different think all together, much more go and more economy. That estate had just had a new, but aftermarket MAF fitted before we bought it. I swapped the one from my saloon and it transformed the car, so I got a new genuine one from it. However, there are many other reasons why performance might be down.

As it happened I bumped into the new owners of that estate the other day. They still have it, its done 60K in 3 years with them giving it a total of 170K, has been to Poland three times, fully loaded with 5 people, luggage and roof rack. They have not had to do anything with the car other than a pair of tyres

I still maintain, the best HDi engine is the 110 2.0HDi 8v, due to its well proven record, lack of diesel particulate filter and the fact its DMF can be replaced with a solid one with no ill effects. Its not the most economical and obviously not the quickest, but its probably got the lowest running costs otherwise.

[imperial21]

I think the 110 hdi is great, i am hopeing for reasonable economy, Hopefully similar to the xantia ! I will be towing our caravan with the car which should be interesting but my caravan is only small, Again i am waiting for my clutch change, got a clutch fingers crossed the dmf is good and will carry on or i will buy a solid flywheel kit.

[wheeler]

Hi
I have heard of the comms units failing and would like to know what faults they can produce ? I have noticed with my car that it can do a few strange things I am sure i saw the headlights come on on there own, Also the air bag light is on, Could it also cause the engine fault light to come on ? Also do all C5 have the fuel / trip computer ? My car when you tap the end of the wiper switch it switches the display to date but press it again and the rear wiper starts going !

Apart from the engine management light all of the above are symptoms of a failing com2000, the only one you've missed out the indicators staying on in one direction.

[addo]

It's sounding more and more economical to fix the Xantia.

[imperial21]

A comms unit is nt a hard or expensive thing to do, Engine light hopefully i will find out tomorrow !
Xantia does need alot of work brakes & suspension etc
A bit of me is considering leaving it in the corner of the garden and fixing it at a later date !
But apparently the C5 is the way forward ?? !!