Hi,

Coming down the motorway on my i6, on cruise at 70 mph, yesterday the car suddenly had two episodes of very short deceleration, similar to the brakes being applied or the fuel supply being momentarily reduced.

Turned the cruise control off and continued as normal.

This morning on the same stretch of motorway I put the cruise control on again to see what happened.

It happened again, once. I turned off the cruise control only this time the engine light was on steadily.

I stopped and restarted (old P38 trick) but the light stayed on. The car ran as normal nonetheless.

Any ideas please?

If the car thinks the breaks have been applied it turns of CC.

Any engine malfunction (or powertrain malfunction to be exact) will turn off the CC.
As since the last time the engine MIL is on, read the error codes (even with a generic OBD reader) to see what's happening.

After I'd left the car for an hour the engine light had gone, but I still took the car diagnosis.

This is what my local mechanic found: A fuel rail sensor.

Here a vid on how to change the sensor:

https://www.youtube.com/watch?v=QuWwrovtTZ4

As you'll all know the i6 B6324S5 engine is a Volvo designed engine built at the Ford Bridgend plant. So the same issue can be found in Fords that use the same family of engines.

https://www.youtube.com/watch?v=8kLyBuP5cNk

Problem solved. Changed the fuel rail pressure sensor – all better now.

Thanks for all the help and advice!

Alan Previous

2008 Freelander 2 i6
1997 Range Rover p38 4.6 V8
2003 Range Rover L322 4.4V8
1989 Range Rover Classic 3.9 V8
2003 Land Rover 90 Td5
2000 Range Rover p38 2.5dHSE
1975 Land Rover 90 SIII 2.25 petrol
1996 Range Rover p38 4.0 V8
1990 Discovery 3.5i V8 (3 door)
1973 Range Rover Classic 3.5 V8 (2 door, ex-Police)