I have an 06 Monte Carlo with about 48K on it. Today on my drive home the transmission was shifting VERY hard. I certianly wasn't imagining it. I tried driving different speeds to see if it made a difference with no avail. I turned the car off, went inside to get a rag to check the fluid.Startedit back up, check the fluid level ( it's fine ). Got in it and took it for another drive and it's shifting normal now??!?!?! Could this be the start of transmission problems or could it have been the computer? If it was a transmission problem would it do it all the time or would it do it for one drive and not another? HELP!

-Jay

 

If you have onstar,press the blue button and they will run a diagnostics.If you don't have onstar,try a place like Advance Auto Parts or Auto Zone.They will do a diagnostic check for free.I had a problem with my 06 last month and it was diagnosed as the transmission control module.It turned out there were some damaged wires going to it.All is good now.

 

Did your check engine light come on? I read somewhere about the wire TSB in the 06 Monte/Impala. What was yours doing? The same thing as mine? I hope it's that simple, I was going to rush out and buy a new car this weekend. I wasn't about to put a ton of money in a car that wasn't that old.

 

My dealer told me that there is a faulty wiring harness and possibly ground wire to the trannyon that year.

 

Did you let anyone else drive it or have you been driving it really really hard? If it's like the transmissions in the trucks, the trans bases shifting on driving style. After a while of normal driving the trans will shift normally.