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Immobilized X300 1997

Posted: Thu Jan 10, 2019 7:51 am
by leo_denmark
Hi all

As you might know, I have a tech support function in the Danish Jaguar Club covering XJ40, XJ-S and X300. A X300 case has just landed in my mailbox, and I need your help !

The mail is long and very detailed. I have Google translated it for now, see end of this post.

The car basically unwilling to start. Some functions work though, and new battery didn't help. I have advised to check (or add temporary) earth connections, but what else is there to look for.

Ther owner has traced it down to a potential Body Processor Module, and that sounds quite sensible. Anybody with experience with this (or one for sale) ??

Thanks in Advance !


I have an XJ6 X300 Executive 3.2 from 1997 - LH drive, SWB.
I have never had serious problems with it in the approx. 10 years I have had it, but since I came out to it one day in October, the car has been completely locked down, understood so that most of the electronics have been out of function (Central locking and alarm system, dipped beam For, Starter , Brake contact for triggering automatic transmission, Interior light etc.). Other parts work fine, such as horn, backlight, position light, fan for radiator, radio, dashboard etc.
Since I can't release the gear lever, I can't rock it a millimeter out of the place (it happily holds in the garage).
The mechanical lock for the luggage compartment no longer worked, but I managed to break into the luggage compartment via the holes for the No. plate. I have then installed a brand new and fully charged battery (VARTA H3 12V - 100Ah) in the car.
I have had all fuses out for measurement in all of the car's fuse boxes - they are OK.
I have also systematically switched around on all one's relays in the car - without it having changed anything.
I also had the power taken off for several days at a time - without result
I've checked the so-called 'Inertia Fuel Shutoff Switch' - OK

Preliminary Diagnosis:
After finding the electrical charts and the Electrical Guide to the model ( ... xj1997.pdf), I have been able to trace all the failing parts back to the controller they call the "Body Processor Module" (BPM), which sits at the back of the glove box with 3 plugs (2x48 pole and 1x6 pole).
I have measured the correct voltage on the BPM at the 3 positions on the ignition key (I have followed this: ... o-i-97-xj6 -x300-lH-drive-normal.html)

I would like to try to change the BPM module called LNA2500BB F02457 (images attached), hoping it will solve my problem. But preferably without it costing a fortune, as I am not sure it will solve the problem.

After what I have read, there are country codes for this unit where 005 should be Denmark? ... -parts.jpg

I have tried contacting in the UK, but they will not sell to me and refer to local dealers in Denmark.
I have also tried unsuccessfully with scrapers in both Denmark and Germany.

So now to my question to you / helpline:
Do you have experience with these symptoms and the BPM module - and can you possibly. suggest how to get a new / used BPM or repair the old one?


Re: Immobilized X300 1997

Posted: Thu Jan 10, 2019 9:55 am
by NMV 1E
After a little consideration I'd concur with the diagnostics as described ...................... My next step if I was to make a suggestion and that maybe to seek out an E.C.U. "specialist" who maybe would / might be able to place the (BCM) B.P.M. on a test "rig" in order to check and test its function (s) :?:

Re: Immobilized X300 1997

Posted: Thu Jan 10, 2019 10:13 am
by pimgmx
Hi Leo,

I'm not a big fan of replacing parts without an EXACT diagnosis first, but in this case it does seem likely that the body processor IS the culprit...

I think your Danish X300 owner will be OK with a used part, as long as it's taken from a Euro-spec LHD car.
There are several on offer through eBay, for decent-ish prices (appr EUR 100 + shipping).
If he considers to buy one off the 'bay: ensure that he asks the seller first whether the donor vehicle was LHD.

One in France: ... 2865439830
And one more: ... 2866342327
One in Lithuania: ... 1567180564 (NB: they often import UK cars and dismantle them locally, this MIGHT be from a RHD vehicle)

Re: Immobilized X300 1997

Posted: Thu Jan 10, 2019 11:37 am
by leo_denmark
Thanks !

Re: Immobilized X300 1997

Posted: Thu Jan 10, 2019 11:38 am
by Brake buster
though a late xj40 , it shared a lot with the x300 model , and i had exactly the same starting issues ( or lack of ) as described above

the body module would indeed prevent the car from starting, as part of the fault finding i manually operated the starter motor circuit in one of the under dash relays, the car started and ran , the signal to make this work normally came from the BPM , i eventually obtained a replacement of the same model number ( there are a few ) and ensuring everything was grounded correctly with the battery disconnected i swapped over the modules and in my case the car then performed correctly ( i now keep a spare just like the CPS )

the good news is these modules are fairly cheap on ebay , but buying in your country may be difficult, and its a ' punt ' to be honest, as mentioned above, fault finding diagnosis is the correct way , but is time consuming and very expensive from an auto electrician etc

best of luck


if not confident , then do not do this, i opened up the under dash relay module with the starter relay circuit inside by removing its lid, and manually depressed the relay contacts inside to start the car with the ignition on , it fired and ran , THIS WOULD BE DONE AT YOUR OWN RISK.......