I know how I will be spending my Sunday.

 

12.5 volts is a dead or discharged battery.

 

Update: As I stated previously, the car would malfunction daily. Last week one code came up P0013 Exhaust cam actuator circuit.
This solenoid was replaced on 1/4/18. The next day a P0118 Engine coolant Temp circuit high input. Since these appeared almost back to back, I
question the ECM. I replaced the solenoid since it was under warranty and the temp sensor. Codes still showed up, so I ordered a ECM from ARES Technologies for
$135.00. Very helpful people. I installed the ECM and followed the procedure for relearning the keys. All good there, as the car starts. Old codes are clear and temp sensor is working.
Now there is a P0315 Code: Crankshaft Position System- variation not learned. So now I will have to take it to a dealer to have this done.
My question is : Is it safe to drive the vehicle 15 miles to the dealership in this condition.

 

Yes. and you wasted your time relearning the key, that does not apply to HHR security is in the BCM. I sincerely doubt the ECM was the problem; you cleared the history when you replaced it. If anything to do with the ECM it is the connectors/wires.

The number of times I have heard of a computer breaking can be counted on 2 fingers and those from abuse like arcing the hot wire on the housing.

 

I have carefully checked over the wiring harnesses under the dash, in the engine compartment, connectors pin condition etc. This whole problem started
with a failed oil pressure sensor contaminating the ECM connection. I posted a picture of it on this forum. I found that it was hard to believe that oil
can travel up through the wiring on the conductor itself. Some searching found an explanation, capillarry attraction. Over the past week I have checked and cleaned
the ECM connector, as there was still some oil residue. As for the key relearn, my manual states that my keys have a transponder in them( Pass Key 3 type.)
The ECM came with instructions for the relearn procedure, which I followed. Also, the codes for Ex. cam actuator and ECT would reappear every time I would
clear the codes and restart the engine. The codes did not return after 3 restarts with the new ECM. Hopefully, after the dealer relearns the CPS I should be good to go.

 

I know it came with the instructions. I also know that the chip interacts with the BCM in the HHR. The ECM when used in other cars might handle the PK3. I absolutely know these facts from personal experience.

As to the P0315 that is a code you will only get from a new or reprogrammed ECM, it means the data does not exist. If you had gone to a junk yard and got a used ECM you would not get that code since there is data present, probably incorrect but present. Also from personal experience.

Perhaps, the oil in the connector did some other damage. After a few months let me know if I should add a finger to my count. I bet that after the CPS variation is learned the cam faults come back. I will be happy to lose that bet. The clearing of codes by counting restarts is by drive cycles i.e.: cold start to hot shutdown.

 

I'll let you know how it goes.

This is the picture that I took when the oil was discovered. Sorry about the haziness. It was very humid and this was taken with a flip phone. The whole lower part of the connector is covered in oil. Then, I found the sending unit leaking oil.

 

My tuned ECM from ZZP, came with key relearn procedure. Car would not crank until this procedure was performed correctly.

New engine purchased from ZZP shortly before the ECM, I didn't have to relearn crank sensor.

 

SS may be different, I know when I put a reprogrammed used ECM in my 2011 It worked fine for a couple of days before I read the directions and relearned the key. .

Because there is no code for a bad variation only for an empty spot. A new or reprogrammed ECM will have a blank spot in the memory bank. I did not "have" to when I had the used engine installed in my 2008. There won't be a code, but it may not run as efficiently as it could.

A place that tunes will usually dump and reenter data like that or just enter new tables where needed.

 

LR ,,, here is my 2cents from having hundreds of hhr's and lately having 3, 08's that have had the same type of probs u describe and we found that all 3 had bad abs brains that would make the gauges go crazy and throw all kinds of codes and they would come and go , not saying its your prob but i find it funny that three 08 now have had the same probs , we had to find the same part num brain and refresh it as it seem that they are 08 only so maybe that is the prob again i,m no brain like some but just what i have had from all i have had good luck happy new year too u all from dave and crystal ,,,,,, a simple test is just up plug the brain yes it will throw a abs light but takes it out of service and c if it keeps freaking out again good luck