Picked up a 2011 HHR LT1 with 35,000 miles on it a few months ago and have had a few issues with the automatic trans and was wondering if anybody else has had similar. The first problem it displayed was a seriously hard shift in all gears, it would even bang into gear from neutral. This problem was very intermitant and would always go away by simply shutting the ignition off. It seemed to me as if the converter was locked up and would not unlock although I had one technician suggest that it might be an increase in line pressure. There has never been any check engine lights come on and I have taken it to be sure there are no codes in the computer. They even suggested that I drive it for a while with it banging each gear to see if it would throw a code, needless to say I chose not to follow that suggestion.

Now that problem hasn't surfaced in a few weeks but it now appears to be hunting for the right gear or going in and out of lock up, not sure which, under steady throttle or very slight acceleration. This has me more concerned because it will do more when cold and you can watch the the tach jump 500 rpms and drop right back again several times in just a few seconds. Of course you can control it by giving it more or less throttle but it does seem to be getting worse.

The car has not been to a Chevy dealer but my normal mechanic is a former GM mech and assures me that there are no codes to indicate that anything is wrong. I know it needs to go to the dealer but before that massive time invesment I was hoping someone has had a similar problem and could share.

Thanks and sorry for the disertation.

 

Check the electrical connections between the trans. and the TransControlModule first. The wires connect to the trans at the front lower driver side. The TCM is one of the small black boxes mounted in front of the "under hood fuse box".

If you still have drive train warranty use it. You may get lucky with a good dealership.

 

Welcome to the Forum...as for the tranny, donbrew is correct. Under powertrain, a good dealer should help with the tranny issues

 

to the forum pro50stude!

Don nailed it in Post #2, check the TCM connections and then get thee to a dealer.

 

I agree with the others about getting it to the dealership. At the very least you will have it documented within the system which proves to be helpful in the future if needed. Please, let us know how things are going with it.

Michelle, Chevrolet Customer Service

 

Checked what connections I could reach and did not find any problems. Have an appointment with a local dealer this Thursday and will post results when available. Had to wait for their transmission mechanic to get back off vacation.

 

Okay heres my thoughts. Mine has never banged into gears but it did hunt for the right gear. I could be crusing down the road at a steady speed and i would feel the car pulsating them the tach would jump up and down about 500 rpms as you said.
I took mine to the dealer to document the problem. They said nothing is wrong. Sound familiar. im at 72,000 miles now and it does not do it anymore. Have no clue what it is or was. But it has completely gone away over the past 10,000 miles.

I would love to know what it was.

 

Check the fuse in the main fuse box labeled tcm, it's either number 41 or 43. It's possibly loose or blown, there are extra fuses in the lid swap or out with the appropriate size I believe 15 or 20 amp. I would def check that before making a trip to the dealer. Might be helpful to reset both 41 and 43 as the other controls the ecm. Just unplug and wait about 5 minutes and then plug back up. Good luck and let us know if this helps

 

Also check fuse #25 in the interior fuse box.

 

OK guys here is the rest of the story. When I took it to the dealer on Thursday, the transmission guy found 2 codes in the TCM, none in the ECM. The codes indicated that the hard shift was being caused by excessive line pressure. I understand this happens when the system detects some kind of non lethal problem in either the transmission or the engine, hence it would reset when you cycle the ignition.

The other code indicated that there was a problem with the PWM solenoid or pulse width modulator solenoid. I understand that this unit is what controls the lock up of the converter. It is supposed to be a more efficient method than just a straight lock up, there by producing better gas milage.

I was told it was about a 5 hour job so thank God this thing has a 100,000 mile drive train warranty. A great big thanks to Chevrolet for standing behind their warranty and to Jeff Barnes Chevrolet for taking such good and courteous care of me during the repair. It is nice to know that some things still work the way they are supposed to. And also would like to thank Michelle from Chevrolet Customer Service for taking the time to read and respond to those of us with concerns.

Hope this post helps someone else with a similar problem.