I am interested in a 2006 Pontiac Grand Prix GXP I saw on my local Facebook marketplace. The owner told me “transmission has issues. It takes off in second gear. I’ve replaced the TCM, and all it needs is reprogrammed.” Would this be a big expensive fix?

1 hour ago, pontiacfanatic22 said:

I am interested in a 2006 Pontiac Grand Prix GXP I saw on my local Facebook marketplace. The owner told me “transmission has issues. It takes off in second gear. I’ve replaced the TCM, and all it needs is reprogrammed.” Would this be a big expensive fix?

Be careful! Who replaced the TCM? You or the other guy? Why? What codes were set? Where did the new TCM come from? If it came from a GM dealer why didn’t, whoever bought it just have them flash it? A re-flash should only be about $100-$200. 

1 hour ago, Last Indian said:

Be careful! Who replaced the TCM? You or the other guy? Why? What codes were set? Where did the new TCM come from? If it came from a GM dealer why didn’t, whoever bought it just have them flash it? A re-flash should only be about $100-$200. 

That’s all the owner told me, so I guess he installed it himself because he didn’t say anything about codes or anything like that.

14 hours ago, pontiacfanatic22 said:

That’s all the owner told me, so I guess he installed it himself because he didn’t say anything about codes or anything like that.

Ok if he didn't erase them they should still be there! Is the check engine light still on when the car is started? Before you buy anything you need to determine what is what. Is it just the TCM or something more.

Not sure if this will be much help Alex, but if you can take it for a short test drive run it by Advanced Auto. They will scan the codes and should be able to tell you what's going on. If you can't test drive it find out if Advanced has a scan tool in their "loan a tool" program. I don't know if that'll help or not bud but its the first thing I'd try.