I have 2000 grand prix se . i bought it off a guy cheap he said the tranny needed to be replaced. big deal put one in. It had the symptoms of lugging engine in gear and would barely move. SO i put the used tranny in. It went in reverse i put it in drive and it killed it. kept doing it. Grabbed a scanner found some codes that led me to the common melted wires by the A/C dryer. I repaired the wires and erased the codes. It was running a little rough and shifted hard thru gears. Engine light came on. I pulled codes p0742 tcc stuck on. p0336 crank position sensor ckt A performance. I replaced the crank sensor still same code 336. I checked voltage and ground and monitered green wire at 8 v on 0 v off. SO it should be working. the TCC is stuck on. I took out the fuse to make sure it goes off and yes shifting into drive kills it. so i replaced the fuse and it still shifts hard and gets stuck on. the tranny i put in had 129k on it and has new filter and fluid i added a can of seafoam trans tune to try to unstick the valve. IT seems to get better each time i drive it but still (thumps) into the next gear and high revs sometimes into begining gears. WOULD a relearn fix these problems? I HIGHLY doubt that the tranny is bad or that the tcc should be bad due to low miles. COULD the short in the wires fry that solonoid ? It runs great and sits about 2000rpm at 60 mph. IDK what the normal is. PLEASE help with any ideas. my next step will be a trip to someone who can relearn it. COULD the computer be fried from the short ?
