Don't know, I just purchased the truck. Have not had cranking issues due to low voltage so I haven't load tested it.

 

The computers need more than 12 volts to run right at under 9 volts they won't even try. "Runs fine" does not indicate a good battery.

 

What were the initial codes? This don't make sense.
Have the battery load tested. Borderline battery can cause weird things to happen.

 

Sir, "runs fine" was not mentioned relative to battery voltage or condition. "Runs fine" was used as engine operating without hesitation, misfire or other commonly used phrase in order to give as much pertinent info to those who are so inclined to offer other than basic insight. Being this is my first experience with the HHR is why I am here asking for suggestions relative to HHR nuances and common failure issues. I do have extensive experience in vehicle maintenance and repair, just not with the HHR. As a point of reference to helpful forums I was under the impression this forum was similar to one of the SSR forums where there is a vast array of technical sharing available. As with all mass produced corporate marketed vehicles, cost cutting and shortcuts wind up costing us enthusiasts time and money. Shared experiences is what makes all this enjoyable to me. That being said, my next step is to perform a battery test as not to overlook the basic as I believe you suggested. Do you have the required battery specifications to share with me other than needing more than 12 volts to "run right"? If so, thank you for being helpful to a newbie HHR fan.
I really appreciate anyone being helpful. .

 

The codes were P0606, P2101, P2149, and P2155. Also the ABS and T/C lights are illuminated constantly, never going off even after clearing the aforementioned P codes. I didn't consider testing the battery as the cranking voltage didn't seem substandard. I will test the battery and go from there. Are there any known or common electrical connection points of concern or problematic to examine as well?

 

Brittle! Excuse me! Bye.

 

I suggested the battery as , I have experienced a dead battery at 12.3 volts static, this SS as you stated has been sitting so the battery condition is suspect. The computer system needs voltage to compute properly, the alternator can’t recharge the battery and keep the computer running, so the lights on the dash start acting up.
I’ve seen many times money spent on new this and that, when it was the battery causing the issues .
Been wrenching on cars since 1962, learning something new every day ever since!

12.6 volts and up 650 CCA and up.

 

This is why I asked about the codes - to see if they were consistent. I was wondering why no one had asked about the battery. One that’s been sitting that long, if still useable, can’t have much life left, so there’s nothing to lose replacing it, and there’s no point trying to diagnose electrical problems with a questionable battery.

There are SO many cases of weird electrical problems in these these cars that have resolved by replacing a “good” battery.

In many cars, if the battery will start it, it will run it. That’s not even close to true in these cars.

Just replace the battery and start over.

 

Ground wires at the transmission down to the right of the oil filter housing, on the rad cradle above the driver’s headlight for grounds
do not mix up the EPS power cable at the left rear of the fuse box. Carful of the red wires at the front left lug on the fuse box under the hood one comes direct from the battery, the other goes forward to the starter and alternator.

The battery cables in the back spare tire well .

The circled red lug is the EPS power The X marks the battery cable to the fuse box then on to the starter

 

Thank you sir. This is the type of info I am needing. Every vehicle has its unique quirks. Any of you guys using AGM's or standard ok?