Good Morning

Cruise control stopped working few weeks ago

So yesterday I replaced the silicone hose and T piece

It still didn't work so whilst I was at it. I put a replacement steering wheel on. Thinking the control may of gone on the old one.

Still nothing.

So I'm left with the brake switch or the vacuum side under the bonnet itself

Any way to test either of them ?

Thanks in advance

Dan

If it is the P38 from Your signature it will have the older CC ECU, which is prone for intermittent operation. I swapped mine for a later one from the facelift model (made an adaptation with the plug like this one https://ejcruz.smugmug.com/Other/Range-Rover-P38/).

Worked fine for me since the swap.

It could also be the little pump, hoses or vacuum valve inside the box with the actuator. ECU generally just need re-soldering & possibly capacitor replacement.

Mine has intermittent operation of the vacuum valve, so fails to engage.

Funnily enough I fixed mine today by changing the hose and was surprised it works (car was laid up for 3 years prior to me acquiring it 9 months ago.

Now the cruise control works, the bloody thing is clonking under braking and acceleration - will search and start a separate thread on that.

KCR wrote:

If it is the P38 from Your signature it will have the older CC ECU, which is prone for intermittent operation. I swapped mine for a later one from the facelift model (made an adaptation with the plug like this one https://ejcruz.smugmug.com/Other/Range-Rover-P38/).

Worked fine for me since the swap.

Thanks for that

Mine is the model in my signature.

Iv ordered a later model CC ecu, where abouts is this located ?

If I recall correctly, is a small silver-ish box located besides the steering wheel, inside the dashboard. For mine LHD is on the left of the wheel, towards the door, I assume the position in a RHD vehicle should be same, but "right" of the wheel.
I think you get to it only by removing the under steering wheel cover.

Thanks for that. Il wait tol the box turns up and give it a go

Pete12345 wrote:

It could also be the little pump, hoses or vacuum valve inside the box with the actuator. ECU generally just need re-soldering & possibly capacitor replacement.

Mine has intermittent operation of the vacuum valve, so fails to engage.

Thanks for that aswell Pete.

Il go check that also

Grizzly … maybe too late. You should look for either a ECU from a 4.0 or have someone with a Motronic P38 and Diagnostic equipment, to change the settings. There are 5 of them, P38 4.0 & 4.6, Disco 2 4.0 & 4.6 and one which is called „default“. Hopefully You bought one with a plug and a pigtail?

Only time will tell haha

I will let you know when it turns up. Going from North Lincolnshire to Cornwall in July so would like to get the cruise back working by then