Thread: D2 V8 Cruise Control Stopped Working

Originally Posted by Southernman1972

The cruise control on my D2 V8 has stopped working. Vacuum lines are all ok as replaced them a year or so ago. But the motor on the vacuum pump doesn't seem I be running when dash switch is turned on. Has anyone had to replace the vac pump or is there a cruise control module hiding somewhere that could be faulty. Brake switch is ok.

Can't help with D2 but D1 had a module underneath/behind the glove box. Could be the same. Vaccy pump came to bits & internals could be inspected & cleaned.

I have a feeling the steering wheel "cotton Reel" (also known by another name which eludes me for now) but is located under the steering wheel plays a part in it's operation As well as the horn & something else (???). May be able to find more info but it is a long time since I buggerised around with mine & now the car has probably gone to God.

If it's manual check the clutch switch too, the cruise control ECU is connected to C0239, it's quite common to be water ingress or corrosion in that area

further to the normal suggestions:

Have you recently made any mods, specifically have you installed LED type rear brake light globes or something like that.

Found out the hard way myself, install LED light globes into some vehicles and cruise won't work.
The CC system requires conventional globes as it checks for some resistance across the globes for it to work.
LEDs don't do that, unless you add a resistor across it.
I had this happen in my D1, and to keep CC working all I did was remove the highmount LED and reinstall a std globe. Kept the LEDs for the tail/brakes .. no worries.

from RAVE there are 3 fuses, 1 fusible link and a relay that may all come into play in some way too.

With the TD5 D2,the fuse for the horn also was for the Cruise control.

Going through deep water filled the horn with water which can cause the issue.

Don't know if this was on all models.

Originally Posted by sierrafery

If it's manual check the clutch switch too, the cruise control ECU is connected to C0239, it's quite common to be water ingress or corrosion in that area

Well bugger me! I've been having a problem with the cruise control cutting out when I hit a certain type of bump in the road. I assumed it was a brake switch problem and replaced the brake switch, which lead to an improvement but didn't eliminate the problem. I've got a new clutch switch somewhere so I'll try replacing it.

Re the horn/CC fuse, this happened to me not long after I got the Disco and it was only thanks to AULRO that I thought of looking at it. I suppose there must have been some logic in Solihull in putting the CC and the horn on the same circuit but it beats me.

Thanks for the replies. It's an auto and no mods. The horn works and switch light comes on so there's power to the circuit. Does anyone know an easy way to test the pump?

Originally Posted by 4bee

Can't help with D2 but D1 had a module underneath/behind the glove box. Could be the same. Vaccy pump came to bits & internals could be inspected & cleaned.

I have a feeling the steering wheel "cotton Reel" (also known by another name which eludes me for now)……………...

Clock spring?

Originally Posted by RANDLOVER

Clock spring?

Yes that's it. I was close though. LR Might have another name for it for all I know.