Cruise control system faulty

[kostaspach]

Hello from Greece, i saw twice the error Cruise control system faulty to my citroen c5 mod 2006 2.0cc petrol automatic.
Untill now For this message i have change:
Speed sensor near to the gearbox
The two front valves at the gearbox
Break valve down of the pendal
No one in greece can give me an answer
Further more above 110km/h do not show me the message that the suspension lower like the past.
I do not know if is the same reason for the above problems. Any idea?

[GiveMeABreak]

Hi and welcome.

Do you have the fault codes from the vehicle? When you have a message or a fault like this, there will very likely be a fault code stored. If you have ant codes, list them here and we can try to help you. Quite often, if there is any issue with the engine management, it will cut all functions like cruise control and the speed limiter for safety reasons. This will normally be reset again when the engine is switched off - but if the fault happens again, then the same thing will happen. So you need to get to the bottom of the problem.

[kostaspach]

Thank you very much For your reply. I do not know where i can find the error code.

[GiveMeABreak]

You need to get it hooked up to a diagnostic code reader (preferably Lexia) which will interrogate the vehicle’s ECUs for faults. The codes will help us to determine what may be causing your problems.

[kostaspach]

Hello again. We found a fault with code u1205 regarding with the angle of the wheel. We started the engine, remove the fault and we went a distance approximately 6km with 130km/h. We did not see message of lower suspension. Further more, the radio do not change the volume with any change of the speed. The volyme control is active.

[GiveMeABreak]

To be honest I've never actually noticed any change in the speed controlled volume function on any of my PSA cars. I think it is very subtle, and I've never notice it change either!

[myglaren]

To be honest I've never actually noticed any change in the speed controlled volume function on any of my PSA cars. I think it is very subtle, and I've never notice it change either!

Same here, must be very subtle.

[kostaspach]

Regarding with u1205 fault?

[teuski]

u1205 is "normal" on facelift mk1's, should be no problems with that

Does your car have two switches at the brake pedal? Have you checked them both?

[kostaspach]

My c5 is mk1 facelift automatic transmission. I changed one brake switch which is bottom of the pendal. Where is the other?

[Hell Razor5543]

It may well be that there are TWO switches in one casing. How many pins are there in the connector? If there are four it has both switches. They operate in opposition with each other; one is a push-to-make switch (mainly used for the brake lights), with the other is a push-to-break (mainly to disconnect the cruise control). As the connector can only go in one way around you don't need to worry about getting the switch connected up the wrong way around. If you use a multi-meter you can test both switches to see if they are working properly.

[kostaspach]

This was the previous switch

[GiveMeABreak]

Like we've said, we really need a full list of all the fault codes to help you further - you can start replacing parts, but unless you know the cause, you will only be out of pocket. Put your VIN number up and ALL the fault codes that are recorded.

[Doo]

Not sure if this will apply to the Citroen, but I have seen vehicles lose cruise control because the tyre sizes had been changed on one axle or something as simple as one set of tyres being worn out and the other set almost new!

It can have an effect on the ABS, but because the wheels rotate at different speeds while the vehicle is turning (the differential between the nearside & offside wheels) the ABS system can compensate.

I would also check the battery and alternator outputs as a voltage variance can affect various systems.

Tyre checks can be done for free just by using visual cues. The voltage check is simple using a digital volt meter.

Like I said, it may not apply, but it's always worth a look....

[GiveMeABreak]

My c5 is mk1 facelift automatic transmission. I changed one brake switch which is bottom of the pendal. Where is the other?

There is only one switch - but is dual function. Be aware there are 2 possible types of replacement switch - a manually adjusted one and an automatically adjusted one. Your picture indicates a manually adjustable one, so caution is needed on refitting it to ensure correct operation. I can help you with this once you supply your 17 digit VIN code.