P38 Immobiliser Problem

Please Can Someone Help
My 02 Range Rover 2.5 Dhse Will Start Instantly Then Stop Just As Quickly . Diesel Specialist Diagnosis Came Up With Immobiliser Active.
I Have Tried The Emergency Access Code But Still The Same.

Car Is About To Visit Main Dealer But They Seem A Little Unsure

Any One Come Across Similar Problem?

Does the problem happen in the same location all the time?

Have heard of mobile phone masts causing interference to the immobiliser system. if you are a member fo the AA or RAC see if they can give you any information regarding locations of similar breakdowns.

Hi very much doubt if the car is immobilised as it would also stop the starter and poosible bring up a message on instrument pack,i have had this before its sounds similar to when the engine ecu has lost synch with the becm,but this will normally bring up faults on the message display,to let you know is there any other symptoms before this any other electrical faults,has the battery gone flat at all does the car unlock correctly on remotes anymore info might help.