If you have the proper equipment I would be glad to pay you to flash my ECU and TCU. I have a 2004 Vanden Plas.

I recently had my transmission serviced, new pan seal, fluid, filter. Its working great, but now 2 weeks later, I'm starting to get P1642, P1797 codes and the car is throwing a gearbox fault randomly.
Also gearbox fault - config e.
The gearbox is fine, shifts smooth, no noises, seems to run like new. But today, sitting at a stoplight, the "gearbox fault" came on again. it clears when you restart the car.

After much research, especially here on this awesome forum, a found a number of people that had the same or very similar issues, which they fixed by having the ECU and TCU re-flashed.

Anyway, If I can't find someone I will have to either try the dealer, or buy what is needed to do it myself. On that note, if anyone has any recommendations on the proper software and device to do this myself, please post the info.

Thanks for any help you can give!

 

I really think you are barking up the wrong tree WRT resetting modules. These are CAN communication errors which can be caused by many non-obvious problems.
1. Check and clean the connectors at the ECM and the TCM.
2. If your coils are old, you might consider replacing them. Believe it or not, on X-350 Jaguars, weak ignition coils can cause high energy bursts to jump to the CAN lines and cause modules to re-set and create COM codes. This drove me nuts on my car for months until I forked over for a full set of Jaguar OEM coils (made in Japan, not that other place) and I've never had a CAN code since.
3. One basic test you can do is check the resistance between the two CAN wires at the TCM connector on the gearbox (when you take it off for cleaning). It should be 60 ohm plus or minus 2 or 3 ohms. The terminating resistors in the Jaguar CAN bus are in the INST PK and the ABS module. (opposite ends on the bus). If the resistance is off you most likely have a wiring problem, or a bad connector on one of the modules.
4, The most advanced approach is the find someone who can do CAN bus diagnostics with an Oscilloscope. Tap in to the CAN lines anywhere on the network and you will be able to see all the modules talking to each other. If the signal is not composed of consistent packets of clean square waves then one of the modules may be "pulling the bus down" and causing the errors. Often you can just disconnect one module at a time and find the culprit when the com returns to a normal square wave pattern.

Good Luck
Jeff

 

Thanks for the suggestions. I was planning to check the Connection to the tranny but have not been able to check that yet.

I am pretty certain this is related to the transmission work, as I have never had anything remotely similar in the 5 years I have had this car. I have the transmission serviced, and shortly after am getting "gearbox fault". Seems related to me. I have seen a number of posts where others have had the similar issue after a fluid change. Here is one similar example of the flash helping to fix things..... https://www.jaguarforums.com/forum/x...ed-help-82282/

On a good note, the past number of trips the car has operated flawlessly and the gearbox fault or any other codes have not returned. I'm hoping that my ECU and TCU are just relearning and now working better, I did try a reset.

But I really appreciate the feedback. I know there are a lot of crazy things that can cause problems on these Jags! I definitely will check the ECU and TCU connections. My car has 180K on it, so it probably does need coilpacks as well. I'm fixing a lot of things at the moment so it will last me for a good while! Thanks for the ideas here Jeff. I am also named Jeff.....your super v8 looks nice!

 

Could the transmission fluid level be off?

 

Shouldn't be. I had the service done at a reputable shop. 7 litres of new fluid. went in, new filter, new pan seal.. The tranny pretty much seems to be operating flawlessly, unless it decides to go into fault mode.

Drove again today to work and back, and no fault, ran well. My fingers are crossed that it has re-learned what it needed and wont do it anymore. About 20 miles each way today and no issues......

 

Well my ecu/tcu seem to be happy now. I haven't had the fault come back for about 4-5 days with multiple trips. Tranny is shifting and operating smoothly.

So somehow I dodged a bullet here. Apparently I just needed to put a few miles on the car for it to adjust and be happy again. Yay!

 

I'd still check the level. I too had my VDP changed by a 'ZF specialist' in Columbus...started having issues a bit after that. Took it to a jaguar master mechanic at the dealer in Indy, he said it was in the wiring harness in the tranny, recommended a new tranny. I had found someone on here with similar problems and found their fluid was low and it fixed it.

I had asked both shops if they'd checked the level 'yeah, yeah, we always do that'.
I finally did the measurement in my garage, PITA as you have to get the temp right and measure it thru the drip method. Guess what? low by almost a quart. Filled it and tranny was fine.

Anytime you get something done with service/mechanic and a problem starts happening after with that same part as was worked on...almost always the work that was done.

 

Unfortunately there is no way I can check the level on my own. My driveway is not level, car wont fit in garage, and I would have to put it on 4 jackstands.
I trust the shop that did the work.
Luckily for me, none of the codes have come back for over a week now, and my transmission shifts like butter. So unless it comes back, Im going to call it good!