Speed Control System Faulty

[Gregg1100]

2005 C5 138bhp VTR ------------------- Son's car.

He was driving home last night at about 40mph in six gear and had to stop suddenly. Braked, but
didn't dis-engage the clutch in time and the car stalled. The hazard lights
automatically came on. Started the car again but he received a message stating
'speed control system faulty'. He has restarted the ecu by disconnecting the battery for a while, hoping that it would reset
the error but it's still displaying. The car's running normally, but any ideas
why he is getting this message, please??
Thanks

[citronut]

maybe it will need a DIS-LEXIA pluged up it to clear the fault message

[RichardW]

Sure it will need a Lexia, Malc, however, the fact that it stalled is a clue - the ABS should have stopped this happening, so something has gone awry with the ABS / speed sensor inputs.

[Mandrake]

Sure it will need a Lexia, Malc, however, the fact that it stalled is a clue - the ABS should have stopped this happening, so something has gone awry with the ABS / speed sensor inputs.

I didn't read the original post the same way Richard - I took it to mean he slammed the brakes on and came to a complete stop (not just locking the wheels during a skid) without pressing the clutch.

ABS can stop the wheels from locking when the car is still travelling but not after it has stopped! (in fact ABS is supposed to disable itself below approximately 10mph)

[RichardW]

I forgot about the zero velocity effect....

[citronut]

i was thinking it might have just confused the ABS so just need resetting with a DIS-LEXIA?????

[Doully]

Cheers Dad for putting this post up for me.

Thanks all for replying!

I read an article this morning from another forum that suggested the speed control sensors integrates with the abs and to check the abs sensors/connecting cables. Malcolm you mentioned about resetting the dis-lexia, would I need to take to a Citroen garage or would this be something a normal garage could do?

[Hell Razor5543]

The DIS-LEXIA is a semi-affectionate nick name for the Lexia diagnostics kit used to do a damned sight more than just read the fault codes. Here is the link to all FCF members who have one, and are willing to help out;

http://www.frenchcarforum.co.uk/forum/v ... 19&t=29178" onclick="window.open(this.href);return false;

What might have happened is when she stalled after such a rapid deceleration the ECUs got into a tizzy. Unless something broke, when a Lexia is connected up you will be able to read off the faults, and then clear them.

[Doully]

Thanks for all the replies.

Started the car this morning and the car is no longer displaying a 'Speed Control Sensor Faulty' message. Checked the cruise control functionality and it's working again.

[Hell Razor5543]

Apparently the ECUs do a "count down" after some types of faults. If the fault does not re-occur before the count is completed then the ECUs "assume" it was merely a glitch, and clear it down. Mind you, it might still be worth getting a Lexia onto the car, just to check.

[Mandrake]

That's correct, most "intermitent" fault codes that are logged automatically clear after a while of not reoccurring, how long it takes varies from ECU to ECU. For example the engine ECU on my Xantia V6 will clear intermitent faults that don't reoccur after 40 engine starts - about 3 weeks if you use the car twice a day...

[qprdude]

Always give it a bit of time. Many faults codes take a wee while to clear. Light bulbs, tyre pressure sensors, low oil warning etc, might take a few starts of the car before disappearing. Don't panic!, as Corporal Jones would say.