Here’s an odd one, I was bedding in the EBC Redstuff brake pads: 100 miles of urban driving braking with light pressure, followed by 100 miles of urban driving increasing to medium brake pressure. After those initial 200 miles brake hard from 60-10 mph 5 times, wait for the brakes to cool completely, and repeat. I was on the repeat portion when the following happened: brake hard from 60-10 mph: transmission fault. Turn off ignition and turn on again. Fault gone. Accelerate to 60 the second time and brake to 10 mph: transmission fault. Restart the car and the fault is gone. Do the same a third time: Nothing. Fourth time MIL. Fifth time: MIL and DSC fault.

ELM327 revealed code P0783. I cleared the code and drove normally to let the brakes cool. Neither the messages nor the MIL returned. Is this a wheel speed sensor or wheel hub problem?

 

P0783

 

Yeah, that much I know, but I am not convinced it's the solenoid on the transmission. Why would it only ever happen under the very specific conditions I mentioned, and why did a DSC fault also show up? My thought on the wheel bearing came from the following quote from the ZF gearbox faults sticky, post #17.

While I did not get an ABS or Cruise Control warning, I did get a DSC fault warning under repeated hard braking. The DSC, if I'm not mistaken, also relies on the wheel speed sensors the ABS system uses.

I could try having a Jag Independent shop reset transmission adaptations and see if it happens again while I simulate bedding in the brake pads.

 

I found that when I was having battery problems and removed the battery for charging (about 24 hours) that this was enough to reset the transmission.

 

Well, resetting the transmission adaptations is a software procedure that involves driving the car in a narrow band of speed for some time. Once the procedure is over, the transmission then "re-learns" for 100 miles. During these 100 miles, you are supposed to drive "normally", not even engaging the sport mode. I would think you would want to defer any type of testing to after that.

If you can manage to get access to a JLR code reader, there might be additional codes to help with the diagnostic.

FWIW, my Foxwell handheld claims to be able to do this adaptation reset. Never tried it...

 

I tried replicating the issue today. I couldn't get it to happen. Not under heavy braking, aggressive acceleration, or very spirited cornering. DSC did intervene once or twice but I got no error messages. The transmission worked flawlessly. Maybe I should chalk up what happened the day I bedded the brakes as a freak occurrence?