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This is what i found in my pdf diagnostic info for that code.
System Voltage – P1793, P1798
A permanent supply is used to maintain a battery backed 'memory'. Should this supply be cut, due to battery disconnection perhaps, the 'adaptive shift' values will be lost. This will result in a small reduction in shift quality for a period until the adaptions are 're-learned'.
The TCM monitors the supply voltage and will log a Diagnostic Trouble Code (DTC) if the voltage is not between 7 and 16V for more than 300 ms whilst the engine speed is greater than 1600 rpm. This fault is unlikely to be caused by a failure within the TCM and as such the vehicle harness and fuses etc. should be checked before the TCM is condemned.
I dont know what year your car is, but that applys to "ZF 5HP24" XK8 4.0 L N/A 1997 to 2002 model year
good luck. keep us posted on your repair.
My baby... God i love that sound...
PLEASE NOTE: This exhaust was NOT made by Nameless Performance. Only the High Flow cats were made by Nameless Performance. My exhaust is vary aggressive. I like it that way. That does not necessarily dictate what the cats it will sound like on your car.
The Following User Says Thank You to 2000blackxkr For This Useful Post:
I also had a reading of gearbox fault, I believe it is the transmission, it has to be re-built or replaced. Does anyone know how much that would cost?
My car is sitting at my home and, it will not start anymore, I have enjoyed driving my car for two years and, am having a hard time getting rid of it.
Offered only 800.00 dollars..I was told also it could just be the timing..
I am not sure what to do now. ; ( it is a XJ8 2002...
I had my transmission in my '99 rebuilt 3 years ago for around $5,000. It lasted 40 thousand miles and broke. I am going with a replacement from a junk yard for $3,600 installed. Not happy with rebuild!
1999 XK8 Convertible
145,261 miles Current Ride
1991 XJS - Red Rocket- wore it out
1963-XKE - Roadster - project failed $$
1963 XKE - Coupe - miss her!
1967 XKE Coupe - 1st Love and now gone!