Try using I gear like Snoopy said. If you play with it I think you will like it. When you pull it back to I it will kick off the lockup of the converter (OD) and hold 3rd gear. I love I drive. Get on a road with a few twist & turns put in I and you will see. You can control up & down shifts with the throttle. Tap brake bip throttle coming in to turn ,it will shift down to 2nd. At apex stand on it it will pull all the way to the red line before it shifts. O so fun ! That little 2.2 will pull you just have to keep the R's up ...

 

I have to take the cruise control off. The tires break loose most of the time when I'm not paying attention. Then the t/c kicks in and slows the car and the motor revs and tries it a second time, again kicking the tires loose. It's a pain in the butt so I try to catch it when going up a steep hill.

 

Okay here goes with my suggestion::

The solution is to place the shifter selector into I which means INCLINE...

This works UP hill for power and DOWN hill for transmission braking

Should noticeably take care of the issue.

I do agree however that the ECM/TCM programming SUCKS ... Just not enough torque in the motors to match...

These cars are Heavy and suspension is NOT adequate either...

But I own it now.

197k 06 LS

 

The engine clearly has ample torque since, I can drive it up the hill without all the drama. My Panel has the FE3 suspension and I feel that is quite adequate for the vehicle.
I think that any one that understands controls would agree that the cruise control module is set up very poorly. It is simply a PID loop that was set up by someone that does not know what the heck he is doing. I come from an engineering background. I know how PID loops are set up. When one is set up poorly, the control scheme becomes erratic. The Cruise control module exhibits all those characteristics.
It has become clear to me that this issue has existed with the HHR since the first ones were sold. This issue never should have never made it to the market place. It is also clear that GM has known about these issues since the first year of production. Yet, the issue remains!
I purchased an inexpensive vehicle and, I understand that. I do not like making excuses for something that could have been resolved with a small amount of common sense even before it came to the market place. It costs no more to do the job right the first time. Costs nothing to resolve the issue in future models and perhaps keep a customer. GM has failed me and I will show them my displeasure in my next vehicle purchase. I had until all this, been an ardent supporter of GM as witnessed by my signature. They have lost me as a customer and supporter.

 

I have owned and driven four different HHR Models, not counting having have rented several more. The uphill cruise immediate downshift only exists with the 2.4 litre models. Whenever a short steep change occurs at the bottom of the hill they drop out of overdrive and downshift to 2nd gear the result is a three gear downshift and stay there until just before the crest of the hill.
The 2.2 litre first drops out of overdrive, then if needed later drop down one gear and proceeds. It requires a pretty steep hill to initiate dropping down to second gear. My 2007 2.4 panel was a little worse than my 2007 LT. I believe this has to do with aggressive tuning of the 2.4L, especially the HHR Panel. I only purchase 2.2L models because of this. I have no experience with the 2.0 liter turbo model.