So I bought this car knowing it had issues with the trans. Drove it home in "limp mode", no worries.

Here's what I am not sure about.

The seller, as with his "mechanic" claimed that there are a couple of "sensors" that are effected by cold temperatures as the car ages. He told me that all I needed to do, is start it and let it set and run for 15 to 20 minutes, then the trans should be warm enough to function as it should.

That didn't work. Burnt the hell out of the torque converter and other internal parts.

Had it rebuilt.

Trans shop calls me this past Thursday (Feb 14) to tell me they have it rebuilt, put back in the car. BUT.... it won't shift out of first gear. They tell me that because the trans is electronically controlled for shift patterns (4L80-E) that when they hook it to their "computer" while on the rack, it runs through all the gears and shifts how it should. But when they connect it to the car? Nope. Only first gear. They also told me that they were NOT able to connect to the trans computer.

Anyone have ANY idea's about electronics on the new stuff that would let me pin point as to what or where there could be an issue? Heard there are 7 fuse panels for the car, all the grounds are good. Was told there is corrosion on all the fuse terminals where they connect to the main power and information feeds.

 

The "could be" list is pretty long.

Could be a wiring/connector issue. Corrosion on all the fuses suggests trouble.....on general principles they all need to be cleaned, and all connections relevent to the transmission carefully checked, but there's no guarantee that doing so will solve your problem.

Not sure about XJSs but on the "X300" sedans with the 4L80E transmission there's a known problem where the main wiring harness to the transmission becomes torn/damaged due to movement of the transmission (even when new the jaguar trasmission mount design allows lots of movement...which worsens with age). Careful inspection of the harness and connector is called for.

The 4L80E uses two speed sensors and two shift solenoids ("A" and "B" shift solenoids). These were known to give trouble. Your trans guy is almost surely aware of this and replaced all four during the course of the overhaul....but it might be worth asking. Frankly I'm not sure if failure of these could cause your specific problem.

Of course there's the transmission control module. Failure rate isn't high, though. I'd consider replacing it a last resort after all other avenues are exhausted. And the TCM itself relies on various sensor inputs which need to be checked...throttle position being one of the most important.

Without test equipment that can communicate with the Jaguar electrics your trans guy is gonna be a bit limited. But carefully checking all the wiring is something he CAN do...and should.

Sorry I can't offer anything more specific. Hopefully others will chime in with better info.

Cheers
DD

 

Yes basically everything except the internal gearing and the outer housing had been replaced. I found some wiring diagrams and am thinking I might do as you had said and just start cleaning.