G6 cruise control problems

[GGraham]

Have 2007 Pontiac G6 V-6 auto. Yesterday, cruise control stopped working and it feels like the auto transmission is shifting hard. Also, I put gear shift into "L" and it still shifts through the gears. Same thing with "Drive 3". Can cruise control mechanism affect transmission function, or visa versa? Does this sound like an electrical malfunction? Car has 40k miles, so if transmission/power train, it should be under GM warranty. If electrical or computer, may not be covered. Any ideas? Thanks!

[grfnkl]

Originally Posted by GGraham

Have 2007 Pontiac G6 V-6 auto. Yesterday, cruise control stopped working and it feels like the auto transmission is shifting hard. Also, I put gear shift into "L" and it still shifts through the gears. Same thing with "Drive 3". Can cruise control mechanism affect transmission function, or visa versa? Does this sound like an electrical malfunction? Car has 40k miles, so if transmission/power train, it should be under GM warranty. If electrical or computer, may not be covered. Any ideas? Thanks!

It sounds like a computer glitch with the TCM... but there is always that possibility that it's something else. If you are still covered by the warranty I'd take it in and have it checked out.

[GGraham]

Originally Posted by grfnkl

It sounds like a computer glitch with the TCM... but there is always that possibility that it's something else. If you are still covered by the warranty I'd take it in and have it checked out.

Thanks very much. You are correct, it was a problem with the TCM. Dealer did a TCM 'reprogram' and 'updated calibration' to correct both issues (rough transmission shifts and cruise control). Unfortunately, it wasn't still under the 'bumper to bumper' warranty, and not considered 'mechanical' to qualify under the 60 month, 50k mile 'powertrain warrantly'. Thanks for your help!

[grfnkl]

No problem. Unfortunetly TCM/ECM reflashes aren't covered by most extended warrenties ( even factory). I guess it's better then having to replace something like the trans though a lot cheaper as well!