Fault finding cruise

[Stempy]

Is there a procedure for fault finding on the cruise control without having to be moving?

[CitroJim]

I thought for a moment you were off on cruise there Stempy

I've never yet tried to make mine work so can be of little help.

All I know is that someone once did an excellent write-up in the CCC magazine, the "Citroenian" a while and a half back. It was for the XM but fully applicable to the Xantia.

If you don't have that issue, I'll dig it out for you...

[DickieG]

Is there a procedure for fault finding on the cruise conrtol with having to be moving?

What's the nature of the problem? (apart from not working )

[Stempy]

Well I've had several problems, a split hose which I fixed, then a duff brake pedal, which I replaced, then the relay packed up which I also replaced. Each time I've fixed it, it's worked for a while then packed up again.

I was cruising along the M4 the other day and it just suddenly stopped working just as if it had been switched off. I've done some preliminary checks such as checking the hose, fuse, swapping the relay, and measuring the brake pedal switch, all to no avail.

[CitroJim]

Stempy,

Did you ever get to the bottom of this?

I ask as I've spent time getting mine to (nearly) work. I've been everywhere you have with no absolute success yet.

A good test is to disconnect the ECU connector and run the vacuum pump independently of the ECU by earthing pin 7 and applying +12v from a small battery to pin 1 of the ECU connector whlst you have an assistant watching the bellows. If all is good, you'll hear the pump run and the bellows should pull the throttle wide open. Mine is low on vacuum and only crinkles the bellows a little. If this works, you know that both the pump and vacuum dump valve is good.

Can you feel even a tiny flutter on the accelerator as you engage cruise? If you can then it suggests a low vacumm but conversely suggests the ECU is good.

[addo]

I went through this a while back, and wrote it up - just not sure whether the detail was here or on Grenouilles Australien.

Short form - open the case and retouch the dry or cracked joints with an earthed Weller iron and finest/hottest tip - you'll also need a super set of eyes or a serious magnifier. Use a PROPER contact cleaner/enhancer on the brake switch, too. I also polished the brake switch contacts with microabrasive.

[Stempy]

It turned out to be corroded contacts on the pump connector. A good clean cured the problem. It's all fine and dandy again now, for the time being anyway. Not the easiest thing to get to though.