Having exhausted other avenues of diagnosing inoperative door locks I notice that the CPU is a component in the door lock wiring diagram. Does anyone have experience replacing the CPU? Does it have to be an exact match, same part number? Is that where critical data is stored, mileage, VIN number, etc?

 

I know the CPU controls many of the electrical systems including the door locks which are currently inoperative on my 1992 XJ6. I would like to know if anyone has replaced the CPU to solve an electrical problem. How often does the CPU malfunction and need replacing? Any information about the CPU would be appreciated.

 

I have been following your posts on this since Dec 10. Did you happen to try re-syncing them? As what we have done in the other posts? IMHO I have never read any posts about changing a CPU for a door lock issue. I'm just stating maybe that is why your not getting many responses. I suggest you search the forum using keywords, lock, door etc. I have a suspicion that you can't be the only one with this issue of all the jag people on here.

 

I have synchronized these locks til I'm blue in the face--no joy. I have searched on door locks, CPU, but no one seems to have exactly the same problem. I have changed the module, checked wiring continuity, etc. What may be a clue that the CPU is the problem was the original module got fried so something had to cause that. From the wiring diagram I can see no other cause but the CPU but I'm open to suggestions.

 

So you changed out the CPU?

 

I have not pulled my CPU out yet to get the part number. I'm still wondering if I must replace with exact same part number. Is critical data like mileage, VIN stored in the CPU?

 

You can swap out any CPU within 89-94. I would assume that mileage maybe stored on there. At this point you haven't much choice. The VIN is on plenty of other locations on your car, I wouldn't be concerned with that. Give it a go m8.

 

Well, I know the '93 - '94 won't work--completely different connectors. Checking Ebay I find several different part numbers that have my configuration. There must be differences. How do I find out which one(s) will work?

 

I'm writing the final chapter in this long saga and it has a happy ending. I've read posts on this subject until I'm blue in the face and I finally got down to the nitty gritty--why can't I get ANY of the actuators to work except the fuel flap. I finally started testing each actuator in turn and found that NONE of them worked--they were ALL bad. You test them by disconnecting them and applying 12v to to the ppl/org and grounding the ppl/pnk or vice versa. If nothing happens it's bad.

So I took a trip out to Pull-A-Part and so far have gotten three actuators for a nominal sum, brought them home and they work perfectly! I would have gotten the fourth but couldn't get the **** back door open on the wrecked Jag which had a jammed mechanism so I'll go to the other P-A-P in south Atlanta.

So to all you frustrated Jag owners with recalcitrant door locks--start testing.

 

I seem to have possibly the same problem. The fuel lid lock opens closes when the key is turned to lock/open but none of the
door solenoids activate. I see that by disconnecting the connector to the Door Lock Control Module all the cabling to the door solenoid circuitry is conveniently provided in that connector. So it should be possible to apply power on specific wiring according to the schematic and test solenoid operation and door switch status.

In my case door locking was fine when I put the car away for winter storage.
When I began using it again the door locks didn't work and the 15A Fuse "C4" in the left hand footwell fuse box (Door lock control) was blown.
I replaced the fuse and after that no door solenoid operation, only fuel tank lid lock.