Thread: Immediate stall in reverse.

Hello, new here. I have a 2005 Grandprix with a 3600V2 automatic 3.8 I believe it is, that I'm trying to repair for someone. The car will drive but not reverse. When shifted from drive or park to reverse it immediately stalls out. I have been trying to fix it on and off for a month or two now and nothing will work thus far. I'd like to mention early the car was getting an engine code U0107 which is a TAC module error. I have tested the battery, cleaned the throttle body (dislocated and cleaned), checked the grounds for lose wires. I did fix the issue at one point for a few days by cleaning the terminals with some coke (old trick for the acid) and it worked for about a week, then the code came back. I'm not sure if the transmission is failing, or if there is a wiring malfunction somewhere. I needed some advice because funds for this are not readily available to this person. I know it could be the MAF sensor, or possibly bad terminals for the battery since cleaning it helped, but I wasn't sure if that was just a coincidence. I also wanted to know if someone could point out where the connection from the TAC to the PCM to make sure that's not an issue, but was unsure how. I'm not a certified mechanic in any way, I just continue to learn how to fix things as they arise, so any help would be appreciated. I'm at a loss here, and considering if the transmission is dropping or not. I feel like if it was, DRIVE would not function, but I know cars can be finicky.

Originally Posted by Scottydoggs

hate to say it, but thats sounding a lot like a blown torque converter. same deal happened to a friends truck. if he pedaled it, he could barely keep it running if it was moving, but come to a stop it stalled right out.

and a blown tc = a rebuilt tranny, or at least a used one swapped in there.

That sucks. Is there a sure way to tell? Because yea even in idle sometimes the RPMs will be jumping. I can get it to drive alright, but reverse is an instant stall.

Originally Posted by Scottydoggs

best to take it to a trans shop to be looked at. sounds terminal to me.

you could drop the pan, see if the fluid had metal chunks in the pan.

my tc took a full blown crap on me. locked up the wheels and all due to chunks i believe.

you can see all the metal top right side of the pan, thats the side i drained it from.

it's a throw away transmission, I'd be afraid of losing fluid. But thanks for the advice guys, she's not too happy with it regardless since she's making payments still.