Cruise control doesn't work

[Zedebee]

Not sure how old this thread is, but rather than start another one I thought I would ask here first. My cruise control is occasionally working. once it connects it's fine and all functions work until I stop the engine and restart the car. All the wiring and connections seem fine which just leaves the stalk itself or the clutch sensor. Is there anyway to test these out if I remove them? I don't really want to go down the road of buying replacements unless I know what if anything is faulty.

Have you still got the 2.0 litre? Is it an OEM fit cruise control that has just started misbehaving?

Easiest way to test the switch is to swap it into another Z4 (any E85/E86), if you know of anyone close by, but this seems to be the least likely culprit.

 

[Laysula]

Yes it is the 2 litre, It's a retro fit used stalk

 

[Peggy924]

Hi, those connectors in the pic, are the connectors on the genuine BMW loom. The loom is retro fitted (on facelift vehicles). Pre face lift vehicles had the wiring already fitted. The yellow and purple, and brown wires from the lighting switch are spliced into with the CC loom. The CC stalk should have the corresponding coloured wires connected to those connectors. So basically you are using those two wires to power the CC stalk, and still power the lighting switch circuits as well. There is then a thin blue wire that goes through the bulkhead to the electric box in front of the fuse box, in the engine bay. I have forgotten the connection number, but that can be searched on line. This blue wire basically connects to the ECU. The CC does NOT need coding into the ECU. I think the system works through the Canbus system. IE tells the ECU when the brake lights come on, to switch the CC off. Not sure about clutch sensors, as my car is an auto, and hasn't got a clutch pedal. I retrofitted it to my E86 last year. Works well, but no notification lights on the dash.
I hope this helps.
Paul W.

 

[srhutch]

Hi, those connectors in the pic, are the connectors on the genuine BMW loom. The loom is retro fitted (on facelift vehicles). Pre face lift vehicles had the wiring already fitted. The yellow and purple, and brown wires from the lighting switch are spliced into with the CC loom. The CC stalk should have the corresponding coloured wires connected to those connectors. So basically you are using those two wires to power the CC stalk, and still power the lighting switch circuits as well. There is then a thin blue wire that goes through the bulkhead to the electric box in front of the fuse box, in the engine bay. I have forgotten the connection number, but that can be searched on line. This blue wire basically connects to the ECU. The CC does NOT need coding into the ECU. I think the system works through the Canbus system. IE tells the ECU when the brake lights come on, to switch the CC off. Not sure about clutch sensors, as my car is an auto, and hasn't got a clutch pedal. I retrofitted it to my E86 last year. Works well, but no notification lights on the dash.
I hope this helps.
Paul W.

Cruise loom was only fitted to car manufactured before October 2004, its not a facelift thing.

 

[Laysula]

I've now checked all the wiring connections and stripped and cleaned the stalk. with no result. I've now ordered a new clutch pedal sensor, so we shall see if that makes a difference.

 

[WavyMcGravy]

An easy way to check if the clutch sensor is working is to depress clutch with the engine running and in neutral. The revs should increase slightly when the clutch is down.

 

[srhutch]

An easy way to check if the clutch sensor is working is to depress clutch with the engine running and in neutral. The revs should increase slightly when the clutch is down.

I would have thought that’s more to do with less strain on the engine rather than clutch sensor.

 

[Laysula]

Well I bought a new clutch sensor and made no difference. Still works intermittently. once it actually works it's fine until I turn the car off, and then it won't work again for several trips. So I'm at a loss. could it be a glitch in the ecu or could it be the switch itself? Anyone in the South west fancy trying my cruise control switch on their car. I'm based in Brixham.
Steve