Engine/Transmission (1994 - 1998) shift problem

[oldbusguy]

94 auto trans wikk shift into lock up and od in morning after sitting for 8 to 10 hours however when it is turned off and you start to drive again it will not go into lockup od light goes on and off any ideas ??? bad pcm ? bad lockup solenoid ?? this is driving me to drink and thinking about just shooting truck

 

[LandShark]

Pull the PCM codes and let us know what you find. A possible fix to make the truck more driveable would be to install a mystery switch. If you can lock it with the switch, that would tell you that the solenoid is good. Mystery switch is nice to have anyway.

A bad temp switch (on the side of the trans) could cause this problem.

 

[oldbusguy]

i drove about 25 miles then shut truck off waited about 15 min then drove trans would not shift then i took the pcm out put it in freezer for about 30 min then drove truck perfect shifting so i guess pcm is bad ??????????????????? jack