I've been getting gearbox faults and I would like to check the electrical connector on the transmission as I understand from the forum that this connector can get contaminated with transmission fluid.

1. Is the connector accessible from underneath the car? Any tips on getting it apart?
2. Is the seal / sleeve that seals the connector from the trans fluid replaceable from outside the transmission, or does the pan need to be dropped to do this?

Thanks
Jeff

 

This attached pdf provides good information on the sleeve and how to replace it. Unfortunately you do have to drop the pan in order to release/lock it in place. If you are getting gearbox faults, it may be something else. If you are not at least an amateur mechanic, I'd say it would be worth the money to have your reliable Jag shop run diagnostics on it and check the fluid level. If it has not been changed in the last 60-80k miles, you should be doing a pan/filter/fluid change anyway, which includes the connector sleeve and mechatronics seals.

I am actually going through this mess myself, though unfortunately will be towing the car to the shop as it has developed horrible slippage (no longer driveable).

They say these are rock solid transmissions but they do need to be properly maintained. Mine went 14 years and 150k miles without any transmission maintenance.

 

Erik, thanks for the helpful reply. The fluid was changed 12k miles ago by an independent shop with the previous owner after the pan cracked and leaked. I don't know if he replaced the connector sleeve at that time.

I have been chasing my transmission problem for months but as a low priority as it only happens rarely. Even with the excellent help of the forum the problem seems baffling to diagnose. It only happens at highway speeds (above 40) when I push the accelerator down hard enough to cause a "kick down". The gearbox will jump into neutral and just as suddenly BANG back into gear sometimes accompanied by howls and groans like a pack of demons. Sometimes it throws an error message and goes into limp mode and sometimes it doesn't. It always clears with a re-start and things go on as if nothing happened. It never does this from a stop, even under heavy throttle. In case this would interest anyone, here are the codes I've seen at various times:

P1774 - CAN Timeout gearshift (J-Gate module malfunction)
P1799 - CAN Transmission control module / ABS control module circuit malfunction
U2012 - CAN Communication fault (Dynamic Stability Control)
U2522 - CAN Message timeout from Transmission Control Module (Dynamic Stability Control)
U2522 - CAN message timeout from Transmission Control Module (ABS module)
also "Fault in communication with ECU

No Transmission Control Module DTCs

My working theories are:

• Transmission fluid leaking into the mechatronic connector on the transmission (haven't checked)
• A faulty or intermittent ABS wheel sensor. (No ABS errors have shown on dash)
• A loose or defective wire connection somewhere. (Where would you start???)
• Loose bolts on the shifter cable bracket on the left side of the transmission. (Unlikely the problem but easy to check)
• Engine misfires caused by faulty coils or plugs (unlikely since plugs and coils were replaced very recently and it runs smoothly)

Any suggestions or insight would be greatly appreciated. My car works so beautifully except for this problem but when it happens it's really alarming.

Jeff

 

What is the voltage across the battery terminals after the car hasn't been driven for several hours when checked with a voltmeter?

 

NBCat:

12.6 V The battery is new as of 2 weeks ago. The error condition has not occurred since the battery was replaced but I have been driving like an old lady so not really testing it. Do you really think battery voltage could affect a car with a good alternator running at highway speeds? Even with the old battery the running voltage was over 14V.

Thanks for your help

Jeff