C5 2.2 HDI exl. Being weird.

[jimleshed]

I think I'm just after confirmation of my diagnosis, but my C5 is acting up.

Last week a couple of times it failed to start, as I think after unlocking
it did not switch off the immobiliser.

It then wont relock on the same plip. If I use the spare it locks, unlocks then will start. I think the key fob battery is fine (it will unlock the car at 50 yards distance).

This morning it did the same - but after a bit driving to work in the very icy conditions I noticed that the speedo and Rev counter were not working... And the stupid traffic master system has started bleating about licences... And my auto opening window (ie the pinch system auto opens the window when I close it - been meaning to reset by disconnecting the battery) has, as a bonus, put itself right..... And last week I also had an low anti pollution fluid warning, during a "it wont start" period.

My guess is that the battery is on the way out......still cranks the engine as good as ever though!

I seem to recall reading on other threads that when electronics play silly beggers thats a good sign....

Any thoughts?

Cheers all!

[Citroenmad]

Ive just had to replace the battery on my C5 as it was getting very weak, but i did not experience any weirdness from my car with the old battery.

What does your batter chanrging gauge on the dash say? Is it well over to the right of the gauge? Once your running and the car is charging the battery should have little effect.

Does the car not say immobilier fault on the dash, when its failing to start? Ive had that on a 206, same electrics as the C5. The key has the immobiliser chip, have you tried swapping to your spare key to see if that cures the fault?

Its odd that your car is expereiencing so many faults, and intermittent ones at that. Id like to think they are connected to one fault, but im not sure. Could be an earthing problem maybe?

[jimleshed]

Hi, I dont have a charging guage on mine, but I think it charges fine. Lights as bright as normal. If it wasnt charging it should have a red warning light showing by the speedo.

At any other time my normal keyfob works fine, except when the car is dead cold on a frosty morning.

When it fails to start it deos flash the interior dook lock LED on the dashboard - which I guess shows that it hasnt disconnected the immobiliser. Once I get this flashing light to go out it starts fine.

[jimleshed]

Aslo, just noticed that yours is a series 2...it could be that they sorted the electronics for low voltage by then....

[jimleshed]

Minor Update.

When I drove the car at lunchtime the speedo and Rev counter have started working again....

So...is it the battery or is it just "Normal" for a C5?

[Citroenmad]

Aslo, just noticed that yours is a series 2...it could be that they sorted the electronics for low voltage by then....

My C5 is a very late S1 C5 hatch, not a face-lifted S2 version. Though i think im right in saying that the late S1s are half way between S1 and S2 in terms or electrical and other aspects.

What year is yours? It must be an automatic since you don't have the battery charging gauge?

You say your car is starting fine, and with these cold morning i would have thought it would have been slow to start had the battery be to blame for its eccentric behaviour.

Im not quite sure why your rev counter and speedo would both stop working at the same time, that does point to electrical rather than a failing speedo head etc.

Multiplexed cars like the C5 can get confused at times and give you odd little faults. Yesterday while driving the Peugeot (multiplexed) i wanted the heated window on, but pressing the button did noting, nor did the other two buttons next to the heated window switch - Air con and recirculation. Next time i got in the car they were working as they always have been.

Maybe its just character your car has , or maybe its developing a fault. Though i wouldn't have thought it would be the battery which is to blame, as you should be experiencing slow starting.


A C5 HDi and a Mazda RX8 ... thats quite a contrast

[jimleshed]

Mines a 51 plate, Automatic.

The first time it refused to start last week, it was turning over the engine really well, as it always does. But as its didnt start I got out to lock/unlock (more for the hell of it than any knowledge). The first key did nothing - wouldnt lock/unlock. That was when I noticed the red flashing light on the interior lock the doors button. When I got my spare keyfob, it locked/unlocked fine and started ok. Then I stopped the car, locked and unlocked with the original keyfob, and then restarted it with the original...

I think its just playing games with me. I'm going to leave the spare keyfob in the car from now on...its ok if it dies at home, but wouldn't want to be left away from home with a sticky immobiliser... Hmmm...just wondered what would happen if I locked the doors with the key, would that reset the immobiliser? anyone know?

Yes, the RX8 is a bit of a change from the C5....very very thirsty...but perhaps thats how I drive it....

[KevMayer]

When my C5 had a couple of strange faults some time ago I suspected a dry connection somewhere so I just worked around the engine bay and
inside the glove box and pulled out and pushed back in every fuse I could find, every relay and multiple connection. Also undid and remade all electrical connections around the engine. Most of them I remade a couple of times all in an attempt to refresh the connections which may have oxidised slightly.

The odd faults cleared and to top it all the engine performed better.

Give it a go, just work on one item at a time.

[jimleshed]

Too cold for that at the moment, Kev. If I had a nice warm garage I might consider it. I'll do the fuses in the glove pocket. (Ive had most of them out anyway, but it wont hurt!)

All was fine this morning, no probs. -6 outside, so a couple of degrees lower than yesterday.

[jimleshed]

After a couple more odd episodes over the weekend (speedo/rev not working - then works after 5 min plus switch off) (non start due to immobiliser) I decided to check the battery voltage at rest before I started this am. Its approx 12.08V - and goes up to 14.56 when engine starts - so its charging fine, but bit low at rest.

Another thing noted over the weekend was that the immobiliser light does not flash until I try to start the engine - IE unlock car with keyfob, wait till everything settles (suspension pumps up, light on dash sort themselves out etc) then turn engine over - car then sometime gives warning "bong" and immob light starts flashing. I have found that that getting out and locking the car with the key rather than the fob does reset the immob, so I can stop carrying round my spare key everywhere.

I must admit I haven't yet tried the unplug various connectors and replug idea yet, but what do you all think about the voltage?

[HDI]

Voltage is a little low, but it does tend to to be at lower temps, the only way to be sure about a battery is a load test.

[jimleshed]

Well, I have taken the plunge...

After checking the voltage again..

At rest 12.07V - switch on voltage drops dramatically to about 8v, then slowly climbs back to about 10V
Turn over engine...drops to about 7v - once started it of course goes up to 14.5V - I reckon the battery was on the way out.

So I have changed the battery..that was a fight. For some reason the alarm went off and the new battery was a tight fit. Its bigger than the one coming out...the old one was probably too small a capacity too! I think the 20 minutes of the alarm annoyed the neighbours a bit.


Anyway, new one in and all sorted now, both key fobs work, windows set....will let you know in a week or so if the starting problems have gone!

[jimleshed]

Well, after several below zero days, the car has started faultlessly. No other niggles.

New battery seems to have fixed the problem.

Whoohooo!

Merry Xmas to all, and Happy New Year's all round!