Stumped on Electrical Problem
#22
Jimmy,
It won't budge from Park. I have checked all fuses in and out of circuit days ago, but this morning I decided to check voltages to each fuse with key out, Key pos 1 and Key pos 2. Working on putting it into a table but noticed no power to fuses in Eng Bay Fuse Box for fog or headlights same in Boot Fuse Box for tail and plate lights. This is with Key pos 2 and lights in on position. Even more annoying the Driver Side & Passenger Side Facia Fuse Boxes have power to Door ECUs but windows will not move by switch but if you open the door they go down a inch (which is normal).
It won't budge from Park. I have checked all fuses in and out of circuit days ago, but this morning I decided to check voltages to each fuse with key out, Key pos 1 and Key pos 2. Working on putting it into a table but noticed no power to fuses in Eng Bay Fuse Box for fog or headlights same in Boot Fuse Box for tail and plate lights. This is with Key pos 2 and lights in on position. Even more annoying the Driver Side & Passenger Side Facia Fuse Boxes have power to Door ECUs but windows will not move by switch but if you open the door they go down a inch (which is normal).
#26
How about using the transmission shifter interlock override to try the neutral start?
Okay, I know this is basic, but have you tried starting it in neutral ?
Burnham & Jimmy,
I tried that this morning, pulled the star plug beside shifter and pressed in with key, shifted to neutral but no difference, no crank.
Okay, I know this is basic, but have you tried starting it in neutral ?
Burnham & Jimmy,
I tried that this morning, pulled the star plug beside shifter and pressed in with key, shifted to neutral but no difference, no crank.
#27
Another approach is to cross reference the sub systems that are not working with whatever control module they are handled by. It is kind of looking like your body processor module is non functional. There have been posts before with an owner opening up the module and finding evidence of damage (burned components, etc) after getting stuck at the grocery store.
The shifter interlock is normally controlled by the brake switch, another known weak part. Once the brake pedal is depressed, there should be a faint solenoid noise in the shifter area, indicating it is unlocked. As usual, there is no direct connection between the brake pedal switch and the solenoid. The switch "informs" the control module, which then activates the solenoid. If that module was faulty, there would be no release.
Separately, do you have any indication the ECU has ever been reworked? '97 ECU are known to fail and need a solid rebuild. They are the oldest for our cars, and made during the "capacitor plague" of the 90's. Just a thought.
Best of luck, keep us posted.
The shifter interlock is normally controlled by the brake switch, another known weak part. Once the brake pedal is depressed, there should be a faint solenoid noise in the shifter area, indicating it is unlocked. As usual, there is no direct connection between the brake pedal switch and the solenoid. The switch "informs" the control module, which then activates the solenoid. If that module was faulty, there would be no release.
Separately, do you have any indication the ECU has ever been reworked? '97 ECU are known to fail and need a solid rebuild. They are the oldest for our cars, and made during the "capacitor plague" of the 90's. Just a thought.
Best of luck, keep us posted.
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WesleyFurr (05-06-2017)
#28
I'm leaning in the same direction fmertz. Possibly BPM. More testing and more info. I tried the lock/unlock three times did not help crank but it did lock and unlock and moved the windows up down a little. I also held the key in the lock and unlock position for a few secs and the conv top would go down and back up, even though you can't control it from the console button. Also found out the break lights do work if not fog, headlights or interior lights. Forgot to mention the rear qtr glasses did not go down when top went down. And last I used a second OBD code reader and it connected to the ECM but only gave code of P1000 because I've tried a master reset. Is there a list of ALL the components the BPM controls?
#30
How about using the transmission shifter interlock override to try the neutral start?
Okay, I know this is basic, but have you tried starting it in neutral ?
Burnham & Jimmy,
I tried that this morning, pulled the star plug beside shifter and pressed in with key, shifted to neutral but no difference, no crank.
Okay, I know this is basic, but have you tried starting it in neutral ?
Burnham & Jimmy,
I tried that this morning, pulled the star plug beside shifter and pressed in with key, shifted to neutral but no difference, no crank.
It was what it took to get me on the road and headed home after my main instrument pack went south on me. Worth a try, no cost to the experiment...sorry it didn't bear fruit.
#31
" Is there a list of ALL the components the BPM controls?"
Look at the 1997 Electrical Guide which you can find on jagrepair.com.
The information is probably not all in one place, but by looking at the Control Module pinout lists you can see the "hardware" commanded actions and status and by looking at the Appendices you can see the SCP bus messages transmitted and received (No CAN messages involved in BCP). These will give you an excellent picture of what is controlled by the BCP. Then there are the schematics and connector to connector lists, too.
Look at the 1997 Electrical Guide which you can find on jagrepair.com.
The information is probably not all in one place, but by looking at the Control Module pinout lists you can see the "hardware" commanded actions and status and by looking at the Appendices you can see the SCP bus messages transmitted and received (No CAN messages involved in BCP). These will give you an excellent picture of what is controlled by the BCP. Then there are the schematics and connector to connector lists, too.
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WesleyFurr (05-07-2017)
#32
#33
#34
Gus,
I'm in agreement with fmertz that all the symptoms fit bad Body Processor Module.
I found this PDF on the site "xk8-1997--pages-60-122-.pdf" and it gave a lot of info on what the BPM controls. On page 23 it lists BMP functions and every one is not working on my car. I hate to jinx it by talking about it but i ordered one programed for my car. should be here by Wed. I will post the results.
I'm in agreement with fmertz that all the symptoms fit bad Body Processor Module.
I found this PDF on the site "xk8-1997--pages-60-122-.pdf" and it gave a lot of info on what the BPM controls. On page 23 it lists BMP functions and every one is not working on my car. I hate to jinx it by talking about it but i ordered one programed for my car. should be here by Wed. I will post the results.
#35
I want to report that the Body Processor Module was the problem. I replaced it and ALL problems went away. If you want to see what the BPM controls check out this PDF on the jaguarforums site "xk8-1997--pages-60-122-.pdf" Page 23. To sum up issues, engine will not crank - no power to starter, interior lights and headlights do not work, dash lights do work and you get info from the system check on key position 2, Conv top will not move, window controls not working but upon opening door window drops an inch like it suppose to but will not go back up (controls do not work), no horn and gearshift is locked in park, will not start in neutral, all fuses and relays check out good and interesting or odd symptom that turned out to be a dead giveaway, interior lights do not work but lights on bottom of doors works (the manual calls them puddle jumper lights). I want to thank everyone for all the help. I would never have found the problem without this site and you guys. Thanks again.
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