04GC07COMMANDER

Hi guys. I am relatively new to the Jeep scene. I am a long time Mustang guy but have recently acquired an 04 WJ 4.7 an 02 Overland wrecked for the engine 4.7 H.O. which I am unsure of what to do with an 06 and 07 Commander both also 4.7s. So I have jumped into these things head first I guess. A few weeks ago on my way to PA our WJ with 121k on it clunked and went to limp mode. The codes are P0700 and P0750. I changed solenoid pack filters and fluid last night and reset the ECU/TCM but the symptoms have not changed. I am at a loss with what the culprit can be now. I was thinking possibly the TCM could be the issue but the more I have researched i am leaning towards the pressure sensor input speed sensor and output speed sensor. When I bought the solenoid pack I was contemplating buying a new valve body at the same time but didn't. I am now thinking maybe that too could be a possible issue. I really don't want to throw a bunch of parts in it only to find it was unnecessary or a waste. I don't think the tranny is bad internally I assume its electrical but I don't know where to go next logically so anyone that has any experience your wisdom would be greatly appreciated. I also have a question as to if the TCM from the 02 Overland will work in the 04 or if I need one from an 03 or 04? If this tranny ends up bad i will have to use the tranny out if the H.O. truck and be done i guess. Thanks for any help.

dave1123

Near as I can tell from perusing the FSM, the transmission control solenoid is not engaging. The TCM energizes this relay to supply B+ voltage to the solenoid pack and controls shifting by grounding the solenoids to effect shifting. If the solenoid pack doesn't get voltage, a special solenoid engages to furnish "limp mode", which gives you 2nd and 3rd only. Where this relay resides is the question not answered by the FSM. It seems it's external to the TCM and trans case, probably under the dash alongside the TCM, although that's just a guess.