I have a 94 Jeep Grand Cherokee that will not shift into Overdrive. The Cruise control also does not work. Fuses are all good and the Overdrive disengage switch and relay seem to function properly. Any ideas would be greatly appeciated
Does the speedo/odometer work???
Have someone scan the tranny computer. Sounds like a sensor issue but in this car the code is not in the engine computer. Might be a dealer scan. BTW how do you test the overdrive switch if as you say it does not do overdrive? just because it lights up does not mean much you need to watch/listen the rpm while driving. Does the torque converter go to lockup mode? Thats the little 200 or so rpm drop as you start crusing at moderate trottle.
Most likely he has the RH model trans (A-500). The only electronic things on this trans is the O/D solenoid, TCC lockup solenoid, and the vehicle speed sensor (VSS) If the harness on the VSS is damaged or the plug is bad or disconnected, overdrive will not work and since the PCM gets cruise information from the VSS, it will also be inoperative. I would check the VSS and harness first. Its located on the tail housing of the transmission on the drivers side.
Thanks for the info. I will gheck it out on Monday.