Hi guys

I have a check engine light code and gearbox fault message with just p0778 as the ONLY code. Can anyone help direct me to a link, or give me the steps I need to take to verify if I have to change this part of if it's a wiring problem? Thanks guys!

 

The code is for a failure related to the 2/4 brake solenoid. As a starting point I would remove and clean all of the electrical connectors to the transmission and TransControlModule (TCM). If cleaning the connections doesn't resolve the problem and you don't discover any damaged wiring then the next step is removing the solenoid and replacing it.
I recommend going to the jagrepair.com website and download the tech section for the transmission.
Follow this link to the website JagRepair.com - Jaguar Repair Information Resource, they have a wealth of tech info.

 

Thanks a ton, that's quite helpful advice. Will keep you posted as I progress.