• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

X-308 99 XJ8 Engine ECU and Chip in Key

Share this page

M

Michael J.

Jedi Warrior
Offline
Has anyone found a procedure to program the engine computer to work with the chip imbedded in the key?

I keep getting codes indicating that one of the circuits in the ECM (Engine Control Module) is bad. I purchased a used ECM from a jag salvage yard, but car turns over but will not start. I have been told that the key has a chip in it and the ECM must be programmed to communicate with the chip.

Jag dealer says to bring in the car, well that is an hour tow truck ride. Take the replacement ECM out and install the original and car will start, but only run as restricted performance.

I have not talked to dealer about bring the replacement ECM and the key yet. Wondering if the only option is to bring the car to the dealer.

Does anyone repair these ECM's?

There used to be a shop in Houston that I had one repaired for an XJS, but have no information on if they are still in business or how to contact them.
 
If I recall correctly it is a dealer specific action where you need the computer PDU that is available only to dealers and authorized service centers. The factory PDU is quite expensive, in the tens of thousands. You should be able to have it performed at any Jaguar Land Rover or even some Ford - Lincoln Mercury dealers were equipped to deal with Jaguars if there was no local JLR service center.
Go have a chat with the service manager and you might get some help - maybe ...
 
Re: X-308 99 XJ8 Engine ECU and Chip in Key and Adjusting Variable Valve Timing

I finally gave up, loaded the car on a tilt bed and hauled it to the dealer one hour away. The rough running and overheating issue is allegedly tied to the variable valve timing according to the dealer technician. He thought that the vendor that overhauled the engine that I bought did not properly adjust the adjustable timing piston. They could not (would not) keep the car to make the adjustment. Instead, they wanted me to load it on a tilt bed, haul it home an hour away and then bring it back a week later as if it is not big deal getting time off from work and paying the $200+ towing each way to/from home an hour away. I bought the wrench for the variable timing piston from XKs Unlimited. When you buy the cam alignment tools, most kits have the bar to secure the cam flats and the pin for the transmission flex plate, but not the wrench for the variable cam timing. Supercharged engines do not have this pain in the backside feature. So if you need to do cam chain work on normally aspirated 4.0 engines, buy the additional wrench. Standing at the front of the car, Facing the windshield, Do you bottom the variable piston by turning CW or CCW or is the piston supposed to be somewhere in between? Anyone out there know the procedure?
 
Back
Top