2005 Type X Estate 121k: at 70mph vehicle suddenly entered a lower gear (higher rpm) with Gearbox Fault message displayed, furthermore there "has been some kick" during acceleration. Appreciate any lessons learned. Thanks...

 

jrdelohery, I would say to start with pulling any codes that the OBD port has. You should have a code since the car is saying that it has a gearbox fault. That will help narrow things down significantly. Post the code here and we can take things from there. From the sounds of things, I would venture to guess that the wiring to your solenoids has found a hot spot and now one of the solenoids is grounding out, causing issues with the TCM (hence the gear change, the car defaulted to fourth gear).

 

Not certain code P1111 means. Appreciate any next step thoughts. jrd

 

P1111 means all tests performed and passed

 

The DTC is likely stored in the TCM and not in the ECM.

P1111 means the ENGINE is happy but what about the gearbox?

 

I

 

Finally code PO778. Appreciate any comment. Thank you!

 

Thank you so much for your input Thermo! PO778 was pulled.

 

https://www.jaguarforums.com/forum/x...-p0778-147745/