Can someone help me with how to access the body control / processing module in my 1996 Jaguar XJ6.? A local mechanic has bypassed it to let me start the car but I am still without lights, wipers, turn-signals, etc.
This mechanic no longer available. I am told that the module is a plug and play and I would like to try to replace it myself. So, I need help to locate it, access it (without damaging anything) purchase a used module and replace it.
Only schematic I have seen on the internet shows it to be behind the dashboard, in the vicinity of the glove box. Would appreciate any help you can offer.
Thanks so much,
BobGalviOlive Branch, MS.

 

Wow, the mechanic bypassed the BPM and then disappeared? That's no good. And I didn't know it was possible to bypass the BPM to start the car. So much of the vehicle's electronics are tied into it.

The BPM is behind the glove box as you heard. It is mounted vertically as in the picture. it has one spring pin in the middle, which when pulled outward allows the module to slide downward and out of its bracket quite easily. Then the two multi-plugs can be accessed.

I believe it is necessary to remove the glove box and the air vent duct at the bottom of the dash, then the bottom of the BPM should be relatively easy to see. The glove box comes out as a large unit with the lower dash molding. There are screws above the glove box opening and one at each lower corner of the molding, and a locating pin at the upper right.

If I remember correctly, the nut shown at the top is not actually there. Maybe it is a grommet. I could be wrong. Let us know what you find when you get in there. Harnesses unplugged and/or spliced?

 

Thanks, Richard;
Will try to tackle it this morning. Will let you know how it goes.

 

:There is a BPM available in KC on a 95 but I believe a 95 is different then a 96 in the lighting and such as they tweaked it after production # X as reflected in the wiring guide . Anyway it is exposed to see the part number and you can call them if it is a match?

Avenue Auto Wrecking

If the BPM is on a hot at all times battery source it is possible to do a " Hard Reset " which is beyond the normal removing of the positive battery cable . Without researching the wiring guide to see if so it might be possible it might be worth trying . A hard reset does work on the SLCU which has a inhibit digital signal to the BPM . This signal goes through the large 48 pin BT4 connector above the fuel tank not correctly reflected in the wiring guide anf this connector can be fickle or come loose .

A hard reset works in resetting a item back to zero state as it may have got hung somewhere in it's sequence and is out of whack .



What your mechanic probably did was spice the wire on FC2 - 41 to the FC1 - 33 as the starter relay control wire is seeking a ground in the big picture .

The mechanic you had is one you would like to keep as he understood how it worked and came up with a alternate solution . , rare .Not just a instruction follower , but he did sacrifice the other BPM uses as it comes alive through the ignition switch pin 1 going to ground .

............................:icon_c ouchhide:

 

Another cheap solution for you , if the BPM is hung up in the inhibit mode , would be to splice the FC2 - 41 wire to go in both directions to the original pin on the BPM as well as go over to the FC - 33 wire to the transmission rotary switch as it goes along to the starter relay . This way you might restore the lighting functions of the BPM .

 

OK. Success thus far. Have removed the BCM without much fuss. Now to find a replacement. This is a Jaguar part,Part No: LNA2500AA / 007, BODY No: 3T021404
On the larger label it is designated: BODY PROCESSOR UNIT
LNA2500AA ( There is a circular stamp on the label ABA, the numbers 231 just below that and another small imprint I can't read.)
944 90881 (don't know what this refers to)
AB Automotive
Electronics Ltd.
MADE IN THE UK
THIS IS A PROGRAMMABLE PART

The smaller label is designated with: PART No: LNA2500AA / 007
BODY No: 3T021404
DATE: 26/01/96
JAGUAR PECUS
Any recommendations as to where I might purchase one reasonably?

 

Thanks to all who have offered to help me with this project. The wiring schematic looks a little daunting to me. I am still trying to contact previous mechanic as I don't want to jeopardize the integrity of any systems
by simply popping in a new / used unit.

 

Any LNA2500AA/007 should work. Body number and other marks are not as important. Here's a link for one (no affiliation to me).

Ebay BPM

Did you discover any wire splices the mechanic made, near any of the 3 multi-plugs of the BPM? Something you might need to undo.

The AA version was superseded by LNA2500BB/007. That would work too.

 

Hi Richard; Yes, did see the wire splice. A 3 or 4-inch pigtail. AND, did locate the mechanic that helped me initially. He said that I just have to remove the splice and it's back to its original configuration.
So, ready to install a working bcm, if I can find one.

 

Continuing on with this Body Processor Module issue. I was able to purchase one on eBay. It is older than the one I am replacing. Installed it but it isn't working. Didn't have it programmed because I have been told by more than one source that most of these modules are plug and play units but it may need to be programmed after all. Can anyone tell me where I can get a module (1996 XJ6 Body Processor Module) programmed? I live in Olive Branch, MS (Desoto County), just across the line from Memphis, TN. What I have done to this point is: remove the glove box and surrounding dash area trim, remove the processor, located and removed the splice, installed the replacement unit with no positive results, reinstalled original unit, reinstalled the splice and started the car. Am leaving the unit exposed with the glove box etc lying on the passenger floorboard. One final note: I had originally approached our local Jaguar Dealership, willing to pay their astronomical prices to have the problem fixed professionally. Their attitude was arrogant and dismissive telling me they won't work on Jags this old and wouldn't offer any information as to who could help or service the problem! I don't know. Maybe it's just me. I guess I was looking for a little more help or guidance from this dealership since this is my third Jaguar, the second of which I bought brand new off their showroom floor!

 

Keep me posted on how this goes for you as I have my old donor car with many parts still intact, including a BPM . You're welcome to this, free gratis and if it's the same part number I can put it in the post to you. I won't be back home until Sunday when I can check the part number. It may be the same, although mine is on a 97 3.2 Sovereign. Don't know if the difference in security systems 're USA and Europe will be a factor.

 

The starter inhibit signal comes from the SLCU to your BPM and that may be where your problem is all along . Have you tried a hard reset as the SLCU has a history of getting out of sequence causing problems .

Are you handy with a volt ohm meter as we'll look at some wires .

Have you tried a hard reset yet ?

My BPM is exposed on M'Lady P and we'll look at the numbers for a swap as I'm up the street .

The SLCU is behind he side carpet in the trunk left hinge area

 

By hard reset do you mean anything beyond disconnecting the battery?

 

Yes , the exact procedure I fo not have at this time and time for a nap after dialysis and drowsy meds .

 

The "hard reset" is simply disconnecting and then touching the two battery cables together for 30 seconds or a minute, to discharge built-up module memory. It appears to cure some ailments, others it has no effect upon. Worth a try as an easy task and when other options become thin.

Some dealers could program the BPMs back in the day, but most don't have such old equipment anymore. But if you get a USA version (007 suffix), it should be plug and play. I have doubts that Sogood's BPM would be plug and play without programming, since it is a UK programmed version. But Sogood has been very generous with his offers to supply parts. Thank you, good sir!

Rest well, Mr. Lady P.

 

Hello to all those Jaguar folks who have offered great information to help me work through this problem. Especially SleekJag12, Lady P. and Sogood. Thank you, sir, for your kind and generous offer.
However, I feel that the differences would be a problem since getting something programmed here is proving to be a daunting problem.

Have done a hard reset today. Results were not what I had hoped but, there were some good things. I did regain the instrument panel lights and two outside side lights. One is the left rear and the other is the front right!
However, wouldn't start so back to reinstalling the splice. This may be my imagination but the test drive seemed to be a little smoother with more pep! I don't know. I may have been dreaming but it certainly seemed real
at the time. Prior to undertaking this project I inspected and verified every fuse in the automobile Wow, lots of fuses. One strange thing thou, I do have one headlight that I had from the beginning of the problem. It is the
right front, low beam light. So, no left side headlight, no high beams or fog lights, no turn signals, no windshield washers or wipers, no auto mirrors or rear interior lights, no automatic door locks and auto trunk release.
I am sure there other things I haven't paid attention to.

An internet search led me to a company in New York that rebuilds the computer processors.G7 COMPUTERS in CANANDAIGUA, NY. Anyone familiar with them?
They advertise that they rebuild your module (computer) with a one-day turnaround and a lifetime warranty! But it is relatively expensive. I will check them out and share what I learn.
Thank's again to all of you for your help and support
BobGalvin

 

The circuits in the BPM are fairly (not fully) independent. What I mean by that is that if the wiper circuit is failed, you should still be able to start the car for example. So a replacement BPM having exactly the same problems as your original are unlikely (but possible!).

I would suggest that you need to drop to a lower level of detail in terms of diagnostics before spending cash on a rebuild of a unit that may not be faulty.

I think a thorough check of inputs/outputs for the BPM with a multi meter and the Electrical Manual is required before condemning the unit.


FYI, the BPM cannot be programmed by a dealer. There is no programming of the unit except at the factory. The "Programmable Part" is only for the factory to set up for various market requirements. There is no car specific programming required/possible.

 

Sometimes the hard reset takes more time with a old towel over the battery post and a battery jumper cable clamping the terminal ends . Let sit overnight . This defies theory vut I have seen a difference on locking items .

Don'r expect all your external lights to work

 

"What's in the box??? Things beyond what you would understand, my lad."

I made that up. It's not the actual movie line although it sounds like it fits here.

You've already tried a different BPM, without success. So it is prudent to back up to more of the basics, as Brendan said.

So the right headlight works. The right headlight has its own relay. Have you checked your relays? In particular, the headlight and foglight relays, and the king relays in the 5 fuse locations? RF king relay is ok if the engine runs with the splice in. LF king relay is only for the horn, so that one makes a good tester relay (if the horn works). Worth checking them out. You'll need the electrical guide download to identify them all.

X300 Service Manuals - MediaFire download

The hard reset would also clear out old information in the ECU, which will then re-learn it fresh. So it's possible the drive feels different, perhaps better.

Thank you Brendan for clearing up some cloudiness in my BPM knowledge. Too bad the Brown's Lane factory was torn down in 2008!! No more factory programming!

Bob, we are glad to assist you. We have all been there and have (usually) solved perplexing problems with the help of the forums. So we are just paying it forward.

 

Is this how the splice is set up now? A branch across the two wires, but which does not disconnect the BPM?