2005 - passat Tdi - Cruise control failure

[cheapaschips]

Hi all ,
Last mondaymy CC was working just fine.
last wednesday and since - nothing.
The stalk switch on/off light on the speedo comes on and goes off with the switch so that works. but it won't engage at all from the steering wheel buttons.
I've heard that they use a vacuum valve switch on the clutch and brake pedals as a safety disengagement feature and that it's usually them that go.
I went down to the dealer to get one to try but they didnt have a clue what i was on about. they suggested a part number would help.
anyone got any idea what this part number might be so i can get hold of a switch to try. or better still some ideas of what to try to trouble shoot it myself.
all of the brake lights work so it isnt that.
does vagcom pick up the fault or is it a case of working thru the whole system till you find something?
Thanks
cheapaschips

[shark_90]

I've never heard the clutch and brake switches called "vacuum valve" switches and I suggest you may be confusing your dealer with this. "Brake switch" and "clutch switch" should be fine and they'll probably recognise them as that.

VCDS (now the name for VAG COM) can diagnose the fault but it's not always easy to spot and doesn't necessarily show an actual fault code - you may have to go looking for the operation status in the measured block values.

[snapdragon]

I would also say brake pedal switch/sensor. It is a common fault, and even if the brake lights work, it is a double-pole 4 pin switch, one pair normally closed and one normally open, if one pair fail or they are not switching together consistently it will be classed as faulty.

Make sure brake lights also go off when you let go of the pedal. Sometimes the brake servo starts to fail and the pedal doesn't return up to the correct height and the sensor is not switched.

[cheapaschips]

thanks for the comments guys.
I've got hold a new clutch and brake switch. the weather tomotrrows going to be horendous but i thought i'd give a go to swapping them.
I've got the info from vwvortex on stripping off the console panel and also the brake switch.
Could just do with some advice on the clutch switch.
is it simialr to fitting the brake switch.
(the brake switch is the newest sort that doesnt require the pedal to be depressed to fit it.


Thanks
cheapaschips

[cheapaschips]

Big thanks again.
Firstly - no rain and wind - so i didnt get drenched.
secondly - did the switches this morning. went for the brakes first - no improvement. did the clutch - hey presto - fixed.
okay so it cost me £20 instead of £10. but it's fixed and didnt cost me main ******* money.
great 'how to's' helpd a lot. - i'll be telling anyone with a VW that will l isten from now on.
cheers
cheap

[shark_90]

No problem, glad you got it sorted!