I posted this in the Jeep forum, but never got an answer.....So Ill try here.

My 94' Jeep Grand Cherokee Laredo 4.0 all the sudden does not go into O/D. I tried cycling the switch and I dont get a light at all to show it on or off. The vehicle has about 213,000 miles on it but has been well maintained all of its life.

I noticed the problem when getting on the expressway and not having any speed. It felt like it was in high gear and it the power was gone. If I roll away from a stop and shift manually it acts fine, except it will not go into O/D. I believe the default setting for this trans is 2nd 3rd gear, and maually you can shift from second to 3, but not O/D. Im not sure if I should look into my solenoids in the trans (Gov and TCC or O/D) or if theres something else common to check...not having any response from the O/D switch somewhat raises a concern.

Ive checked the fluid and all looks well there. I am going to investigate the fuses in the PDC tonight and attempt to get trans codes, though as I understand it it flashes the O/D light...which isnt coming on currently, so I dont know if that will work. Any help is appreciated. Thanks!


::::UPDATE::::
Last night found that my TCU fuse was blown. If I replaced it my O/D light came back on and the trans shifted and acted normally. After I went about a mile, it started acting up again. Pulled over and found the fuse was blown again.... Is the TCU itself problematic? Does anyone have a diagram showing power feeds for this circuit?? Thanks