My son drove the 1999 XJ8 home, put it into park and there it stays. The shifter moves, no gears in any position but it does come out of park. I drained the fluid (low, about 3 quarts came out). No debris, light dusting of clutch powder. Cleaned the pan, replaced the filter, new gasket, bolted it up, filled it to overflow. Then ran it through the gears as prescribed. No result. Tipped the car up at the back to get a little more fluid in for a total of 5 quarts, ran it through the gears, no result.
Put the iCar OBCD2 reader on it, cleared codes (P1722 (stall speed) P0790
etc... 3 total, one transmission related) left the car to idle with the emergency brake on in reverse and drive, no result. This car has 90K miles, Jaguar maintained before I got it, creampuff. Shifter cable intact, J Gate working fine, all lights synced, transmission position switch seems to be working perfectly. I am left to think of only 2 possibilities: bad TCM, or a perfect storm of circumstances: the "A" drum failed along with the TCM at the precise moment my son put it in Park. Nothing indicates a catastrophic failure, fluid, though low, was not burned and not totally black. Just a normal, light coating of clutch dust.
Cheers,
Zaphod

 

Dead tranny... A drum is probably bad.

 

Phavas, have you carried out a hard reset?

 

disconnected both TCM and ECM if that's what you mean.

 

hard reset

 

Thanks. Did that. I've checked everything. No codes, no go.
Finally un hooked transmission cooler line at the radiator and got no pressure in any gear setting, so either it's the pump or the A clutch I guess. Freaky coincidence of failure precisely when the car was parked.
Gonna take it apart next week or so.
Cheers,
Zaphod

 

Well mine broke in traffic. Just came to a halt and then that was it. No more gears... No prewarning...