The cruise control on my disco doesn't work,cant see any thing physical wrong,cable etc, so I assume it's an electronic problem. Does it have a dedicated ECU or is it part of the main ECU ? (expensive)
Anyone know.
The cruise control on my Classic didn't work when I bought it. I think the system on the disco is basically the same. So here's what I know -
There is a separate ECU for the cruise control. Yes I think they are expensive but don't know for sure.
There are a couple of common failures on the RRC cruise control. As I understand it, the most common is a break in the ribbon cable in the spiral cassette that is attached to the steering wheel. A repair is possible but it is fiddly.
Another failure is dry joints on the main board in the ECU, take it to bits and re-solder dodgey joints.
Split/leaking/missing vacuum hoses prevents the actuator working. Check all vacuum hoses including the one off the back of the brake light switch.
I could go on but I would suggest as a first step you should check that the system powers up - get a wiring diagram and a digital voltmeter.
Next check the vacuum pump works -this is a simple case of attaching power and ground leads to activate pump and valves, this should also enable you to check the diaphragm on the actuator.
Assuming all that works, you need to check the set switches. I just thought, the disco doesn't have cruise switches on the steering wheel does it? Should be easier to see if the problem is a duff switch, check the wiring diagram to see what should have power and get stuck in with a volt meter.
Hope that gives you somewhere to start but remember the system may be different to that on the Range Rover Classic so I could be talking rubbish. Good luck.
