It looks like I may have a bad Body Processor Module (BPM) on my 2002 XJR and I’m in the process of getting one to replace it. For this -I’m told- I must get the device’s last three digits which are not found on the unit label’s part number, but rather it’s supposed to be located on the VCATS label inside the trunk by the spare tire. Well, unfortunately I can’t find any such label even with the spare removed. So, questions:
Was the label location changed for 2002?
Did Jaguar quit placing those labels for 2002?
Is this 3-digit information found in a different form or somewhere else in the 2002 car?
Could other 2002 California-sold XJR’s (exactly like mine) have different 3-digits?
Ultimately, do I necessarily need those three digits
I would much appreciate any help with this issue.
Just in case you wonder why am I doing this, well, the starter won’t crank, I have no interior lights, no trunk lock or trunk lights operation, etc. The starter relay coil needs a ground signal from the BPM to operate the contacts that will power the starter motor, but it’s not getting it and the opposite side of the coil has verified 12v, plus, the contacts do have power ready to go. Examining the Batt power diagram (ignition OFF) I can easily trace that all the failing circuits somehow depend on signal/status from the BPM. And, circuits that ARE working, such as the “puddle” red lamps at the doors’ bottom corners are ON because they do not depend on anything related to the BPM. Besides, several other people report the same symptoms and a BPM replacement took care of it.
Sorry for the length here.
I’d much appreciate any help with this, thank you.
I seem to remember that when I worked at the Jaguar dealer I found an issue when people put a mount screw through the sun visor mirror illumination wiring and ‘blew’ the fuse. I don’t remember if it was the X300 or the X308 but the body processor uses a power supply common to the visor mirror illumination.
You might look at that system before condemning the BPM?
The label is not in the spare tire well itself, but as Andy says, is on the horizontal surface next to the well on the left side (hidden under carpet.) I myself went on a junkyard search for X308 VCAT labels as I searched for a security module that I could use experiment with in replacing the chips that power the brake lights.
Motorcarman, I much appreciate your input. Actually, it is the “Illumination enable” output from the BPM that directly, and without any fuse in-between, that provides power to the vanity lamps (i.e sun visor), but also to the map lamps, glove box lamps, trunk lamps, etc. These lamps will turn ON whenever their switch puts ground to the other end of the lamps. It seems to me that a short, such as you described, will rather blow the unprotected BPM unit that’s providing that power. Where does the BPM get these 12 volts that it delivers? That’ll be from the LH heelboard fuse box, fuses #5 and #7, where I have already confirmed existing power. These two fuses do not provide common power to the lamps, but rather via the BPM. I tell you, I’m beginning to have dreams -and nightmares- after so much looking and studying these diagrams.
AndyK,
Much appreciate your help. Yes, the label was exactly where you said it was, under the carpet. The funny thing is that this is not the original carpet, but rather a matching carpet strip that I installed there when I re-did my entire ICE system in this car; how can I not remember that I’ve previously seen it there before (other than getting old and forgetting things LOL…) ? – BTW, I’ve worked so much with the diagrams and checking power/fuses and I’ve confirmed power at most or all the BPM-related un-switched power sources/fuses. I’m now beginning to check for more conditions that may affect BPM normal operation, including switched power and switched grounds. This is like a night mare. Again, thank you very much for your help.
Thank you, bdragon. Yes, the label was exactly under the carpet like you and AndyK said it was, so I now have the entire correct P/N if I wind up buying a replacement unit. I’ve seen that others who had similar problems with their XJR’s did resolve it with a replacement BPM. Thanks again.
If you cannot find an inexpensive replacement you can ‘borrow’ one to see if it fixes your issues.
One good thing about working at the dealer or independent shop that repair a lot of the same cars is that you can sometime swap components to test systems.
This is an excerpt from TSB 418-03AM VCATS compatibility.
If further diagnosis appears to point to a defect within a control module, note the 3 conditions on
the following page before interchanging control modules between identical vehicles to confirm
diagnosis.
Refer to illustration 3, which shows a typical VCATS (Vehicle Configuration And Test
System) label, located behind the spare tire on the trunk floor of XK8 models and behind the
trunk trim on the left side of the spare tire on V8 XJ Series. Each label is specific to each
individual vehicle, and lists the VIN of the vehicle along with the part numbers of the CMs
originally installed in the vehicle during manufacture.
In the example above, the part number of the Body Processor Module is identified as:
LJA 2500AG/055.
In the above, the basic part number LJA 2500AG has been programmed during vehicle
manufacture for the specific market and features of the vehicle concerned, and is identified as
/055.
This would be the complete part number for a replacement BPM for the vehicle concerned,
if it were necessary to order one from Jaguar Parts Operations.
Note that the suffix /055 (in the example above) does not appear on the label on
the CM concerned. This number appears only on the VCATS label of the vehicle.
3. It is permissible to temporarily interchange a CM from another vehicle for testing purposes, only if: • The full vehicle history of both vehicles is available. • The history of both vehicles indicates that the CM in question has not previously been replaced by a CM from another vehicle or by a replacement part. • The VCATS label information for the full part number of the CM in question on both donor and recipient vehicle is identical, as illustrated above. • The donor vehicle is known to have no electrical defect.
Thank you, Motorcarman, unfortunately it seems like I’m being attacked by a multiple ghost army (Halloween ?) as another, even worse, problem has emerged in the same car: it has suddenly developed a huge current drain with the ignition OFF and of no less than 4 amp, yes, you read it right, 4 amp, almost like a short. I have verified that none of the 5 fuse boxes is doing this, so there is just one more power branch and that branch is reading the dreaded 4 amp. This is the cable from one of the 250 amp fuses in the trunk, the one that’d connected directly to the starter motor and generator. I’ve verified the 4 amp current reading where this cable goes to the terminal bolt right above the right fender, BTW, is this what they call the “false bulkhead stud connector”? I dunno.
I’m now in the process of trying to access the main terminal bolt behind the generator (what a pain). This is the junction that connects the generator and the starter motor together to the power line (plus the suppression module). Disconnecting one of these two devices at a time and hooking up my clamp current meter will most likely tell me which one is the one drawing the 4 amp, hopefully.
Only when I resolve this will I be able to go back to the no-start, no lights problem, but your response above was much appreciated.
Oh, man!