T/C and engine light on on 2006 Chevrolet HHR

I have a 2006 2.4 HHR. Occasionally I have had the T/C light come on and the car will shift hard. If I turn the car off and let it set for a while the T/C light goes out and the car returns to normal. Today the T/C light came on first and then the Check Engine light came on after travelling about 20 miles. It did not seem to affect how the car performed as far as acceleration but it did shift hard. After turning the car off a few times and traveling about 40 miles the T/C light went out and the shifting returned to normal but the Check Engine Light is still on. What causes this and what should I do.

4 answers
I had the same thing happen to my car it a sensor. Its either the intake valve sensor or the exhaust sensor. Its about a $150 repair bill. But just to let you know once one goes out the other will so have them repair both at the same time. It will save you money in the long run trust me....

Good luck if you haven't had it fixed yet.
Sounds like an intermittent transmission issue. Something that fails consistently when driving the car. Can be electrical in nature, or mechanical. You will need a good diagnosis from a qualified technician.

Here are some links to some shops near you...
http://repairpal.com/directory?address=98296&car_brand_names=Chevrolet

Best of luck.
I own a 2006 HHR LT 2.4L and had the same problem for the past year.At 96000 kilometers it's not normal.So I took it in to the dealer and after three attemps they finally decided to change the two Phasers,the timing chain and the two timing chain binders.GM paid for all of the parts and I was stuck to pay the labor.Beleive me this should resolve the problem or somebody is going to hear from me.
My HHr is a 2006 LT, it has 30,000 miles on it, and my T/C light start coming on, then not to long after that, my check engine light start coming on, I'm thinking about getting rid of my HHr even though I love this car, but when a vehicle start having problem with low miles on it something is not good thing, I will have my mechanic repair it, then my next step is getting rid of it.