I have today installed a new inhibitor switch, which has made no difference at all !
I went to a auto trans specialist who could not get any codes out of either the ECU or the TRANS ECU , they then sent me to a auto electrician who had a different scanner which gave 637 from the ECU but nothing from the trans ecu. the same as my cheap scanner i have at home.
in my code book that came with my cheap scanner, says code 637 is
Data links EEC to 97LE Controller is shorted to ground.
anyway the car starts of in 3 or 4th gear and will not self change gears or allow manual shifting.
have checked fuses, trans fluid level, the economy/ power mode switch stays in economy mode regardless of switch position.

Does anyone know what this means and how to fix it?
please i am at my wits end here.
any help will be greatly appreciated.

Sounds like your Auto Computor is stuffed.

Car is in 3rd gear and will remain in Econ Mode while in LHM.

It was indeed my auto trans computer, i got another from a el v8 from the wreckers, same part number except 2 letters on the end.
installed it, and all is know good.

Cheers

ps how common is it for these tcu's to fail?