97 XK8 that when I switch the car to on, the starter engages and remains engages after the car starts. I have to remove the starter relay to stope the engage after the startup. I have replaced the starter relay with a new relay, but the same things. I have been having many things show up like, Engine Fault, Poor Performance, crankshaft Position Sensor, stability control, ABS, P0335, P0351, P0354, P0355, P0358. I have a new battery and have changed the Ignition Coils around and the same codes regarding the coils show up. Switched the Ignition Controls around and nothing changes. I did a hard restart and the errors, some of them reappear. The issue when I switch the car to the on position, the starter engages and continues after start. Let the car sit overnight and the car starts with no issues, runs perfect for about 15 mins and then the same old crap. Any ideas?

 

Take a look at this Post. If your BPM has suffered damage, hopefully not as extensive as this one, you will need to find the underlying cause for the damage, although, components on module circuit boards have been known to fail i.e. capacitors, etc., and a diagnosis and re-build from ASI could solve your problems.

https://www.jaguarforums.com/forum/x...ad-ecu-168801/

 

I'm sending my ECM to ASI today. Hopefully that will solve some of my issues. The one I really don't understand is the starter engaging when the car is switched on and remains engaged after the car starts. We will see.....

 

The BPM is between the ignition key and the starter solenoid and so it takes a big part in operating the starter motor. It's also the box that prevents starting for various security reason, if the shifter isn't in the correct position, etc. Take a look at Fig 03.1 here http://www.jagrepair.com/images/Auto.../jagxk1997.pdf

A faulty ignition key could be a candidate, too.

 

I went out yesterday morning and the Cat started as normal and ran for 1 hour with no issues or codes. I shut it down disconnected the battery and pulled the ECM out and sent it to ASI. I'm keeping my fingers crossed that the ECM was putting all the gremlins in the Cat. I will probably just replace the BPM to have peace of mind on the starter issue that Pbuck commented above. Fingers crossed.

 

Does anyone know if there are any differences between BPMs in the 4.0 vs. 4.2, Conv. vs. Coupe a/o the XK8 vs. XKR? And is it the same unit used in other Jags?

I've recently also picked up a starting quirk, where everything looks fine, but the starter just doesn't do anything. And then a few attempts later, she starts as if nothing was wrong. Same thing goes for the "Mist" function on my wipers. It usually doesn't work, and then for no reason, it does. Both systems go through the BPM, so it's possible that I may have found a common culprit. I need to look at the schematics more closely though.

 

Jim,
JEPC doesn't show different part #s between 8 and R or coupe and conv., but there are at least 6 based on VIN

X308 is different

Mike

 

Thanks Mike. I'll see what I can find.

 

Update: received my ECM back from ASI and installed it in the Cat.Turned the key and it fired right up as normal. I let it idle for about 15 mins with no codes. Took it out for about 45 mins on the road, run like a new car. Transmission went through some strange shift patterns but nothing alarming, I figured it was learning. Kicked it in the *** and it ran like a scalded ape. In my opinion, my ride is fixed and the issue was a bad ECM. Special thanks to ASI for the quick turn around and a professional job of rebuilding my ECM. I am one happy camper. Special thanks to the members of this Forum who provided input on my issue. This Forum is a life saver!!!