Can bus Fault p1643

[andyg1971]

The fault i am getting amongst two others is p1643, U2522 and U0101 all can bus communication related or lack of in this case between the auto tcm and ecm! I am in the midst of changing the transmission harness in the hope that this will resolve the problem unless i find it to be faulty connectors but that would be too easy in my experience😄 The car in question is my 3.0 v6 05 plate 80k with full history which to be honest makes no difference as its a 16yr old jag but none the less is otherwise a great car. Has anyone else suffered this specific issue? as the p1643 fault seems to be quite elusive in my searching for info. I service and repair my own car and due to this recent fault replaced trans Oil and filter plus mechatronics sleeve and rubber seals, rear abs sensors and calliper slider pins due to binding epb and brake pedal sensor plus new battery even though the old one was just a year old. This all started out of the blue with a stuck epb then developed to gearbox fault, dsc, restricted performance plus engine light and amber warning light with abs warning lit up. Enough issues to scare the crap out of any car owner lol. Anyway to date the car rarely starts unless the j gate decides to reconnect to the tcm and then the gearbox fault goes for a short while but returns before any gear is selected but the engine will tick over as smooth as it should and will rev past the 3k limiter in park with no issues and the on checking the epb it is working and holding/releasing as it should despite still having fault warning on dash readout? confusing until you realise the can bus is the reason for non existent issues as the main problem has a knock on effect on other control modules! Anyway will try and fix this otherwise i have an expensive brick in my drive and these cars are much better when driven.

[andyg1971]

I guess nobody had any ideas as to what the issues could be? 

Now fixed anyway although did come within a nano of selling it cheap after 3mths of chasing my !Removed!.  Upside is i know more about how the electricals work on this car than i would ever bothered with and that fault codes did nothing but confuse the situation. 

The auto box is now silky smooth and not one fault to be had until something else pops up and it will im sure. It dose seem that with the age of these cars the wiring will cause some brain numbing problems rather than module faults, although not saying modules do go wrong but this car is full jaguar history from new upto 72k and ive only took it to 82k in the two years ive owned it without any problems. 

So to date since the issue began ive replaced atf/filter plus all mechatronics seals and sleeve as original was still present. 

Refurbished rear brakes due to sticking sliders with new pins, pads etc.

New rear abs sensors.

New battery just to be sure although that was replaced when i bought it.

Plus Fault code reader which is invaluable if not always lol but it dose read all modules etc.

All the labour was by myself so only parts costs.

Overall happy to go through another winter running this car although next up will be a new radiator due to the bottom looking a little saggy and cam cover gaskets and associated parts. 

[FargoJag]

What finally fixed it?.  I am having the same type of issues with my 05 str.