Electrics problems: Lots of warning lights though no issues

Hello all,

Firstly please forgive me, I'm not very technically inclined and this will be a long post...

I have a 2012 C3 White 1.4 petrol with around 33,000 miles. I bought it from a main dealer around one year ago and am the second owner.

This problem happened twice within a week - on a Thursday and then again the following Thursday. Both times it was shortly after starting to drive - the first my girlfriend was on her way home from a shop, the second I was on my way from home to work.

The following warning lights come on:

Stop braking system error
ABS system error
Airbag error
Seat belt error

When this happens, the steering goes really heavy as if power steering isn't working, the brake pedal becomes slightly heavier (though the brakes still work), the speedometer does not work (at 0 mph), and the electronic screen that usually says when to shift gears says " -- "

When it first happened to my girlfriend, she just happened to be a few hundred yards away from a garage. The very nice guy hooked up his diagnostic computer and looked at it. Unfortunately she doesn't remember exactly what he said. But he said he couldn't see any fault, so he disconnected and reconnected the battery. After doing that the car was fully back to normal with no warning lights on.

When it happened to me, I was in a rush to get to work, so I took it to my local garage where I always go and had them disconnect and reconnect the battery so I could get off.

I took it back to them the next day for a diagnostic investigation. They said that they couldn't tell what was wrong as it wasn't faulting when I brought it back to them. They said I should wait until it faults again and let them look at it again.

The ECUs had the following error codes, but they said that this could also be from disconnecting the battery several times. They cleared the codes and did a road test. After the road test there were no fault codes.

P0606 ECU Fault
U2000 Remote controlled wake up fault
U0415 Fault in communication with the ABS
P0053 Upstream oxygen sensor signal
0150 Vehicle speed information invalid
U1113 No communication with the ABS/ESP
05FF BSI internal fault (BSI reset)

I found a thread with a VERY similar problem, but it wasn't resolved.

diesel-citroen-c3/lots-of-dash-warnings ... -t447.html

This is really worrying me. I spent a fair amount of money on the vehicle and it is very low mileage. If it takes some cash to get it going again I would be totally happy. But I'm afraid that they won't be able to diagnose the problem.

Has anyone heard of this?

Hello omglolmax

My advice would be to start with the basics.

When lots of seemingly unconnected faults appear I would first look at the one thing that connects them all, the 12 volt supply.

Car ECUs don't like an unsteady supply, under and over voltage can also upset them.

I'd start really simple with the battery connections and leads. Look for physical problems like corrosion, are all the connections tight. If you can, remove and clean the battery connections and also check the other end of the battery leads, especially the chassis lead where it connects to the bodywork.

If all looks good then measure the voltage at the battery. I prefer to use an analogue meter for this (as opposed to digital, digital meters 'sample' the supply at intervals, rather than continuously monitoring so it's easy to miss variations).

With engine off you should be getting something around 12 volts or just below, anything drastically below and the battery is likely duff. When the engine is cranked the voltage shouldn't fall more than a couple of volts and when the engine is running you should get a nice steady voltage around 14 volts of just below. Anything much above or below this may be down to a duff alternator. If you see fluctuation on the voltage with the engine running (unsteady readings on a digital meter or movement in the needle on an analogue meter - or by selecting AC voltage on your meter, if you get anything registered) then the voltage regulator is a suspect.

If you do these checks your self please be very careful working near the battery and also the engine when it's starting/running.

All of the above are fairly easy DIY checks, the next step, checking alternator wiring is a little more involved but see how you get on with the above for now.

Hi,
I am no mechanic!! But I had an impressive experience with my C3 (2008), so please make sure that there are no wet electric plugs inside your car ... and no water dripping from washer jets ...:

petrol-c3/leaking-washer-jets-causes-da ... -t584.html