ThirtyFive 21

So we have an M1152 here that every other time you start it up, it won't shift. So you start it up and it drives fine. Turn it off and turn it back on, won't shift out of second gear. This truck has had the transmission, torque converter, tcm with bluechip, and the PCB replaced. We have also tested the TPS and it was within required tolerance. I've been picking through this tm line by line and honestly, i'm stumped. I'm almost sure it's a relay or a circuitbreaker but I was wondering if anyone else had any ideas or had a similar experiance?

there is a switch on the back of the battery box (a little red button), its a bypass switch for when a hmmwv transmission overheats. after it cools down you press the switch and it lets the transmission shift through all gears again. although it seems unlikely the switch could be bad or stuck. look into it maybe try unpluging it or bypassing it. to see if it solves your problem.

Yeah tried that a bunch, won't beleive what it was though ;p some jack wagon thought it'd be nice to switch the tiss and toss wires...

HAHAHA! oh man, the stupidest things that get us. Now we all know to check that in our inspections when dealing with something like this.