Stephanie

I bought a used HHR with 165000 miles. No lights except tire pressure which the seller told me about. Drove 200 miles and ABS, traction control, and sometimes check engine, theft deterrent, and brake lights come on. Took to dealership they replaced battery. Drove 50 miles and all lights on intermittently again. Shifts hard when check engine or theft deterrent lights are on. I'm now $1200 in and nothing has been fixed. I have reset the ECM by disconnecting 50 amp fuse. Drove 100+ miles with no lights and now repeating system. Any ideas?? I have purchased a new ECM but haven't installed yet. Please help if you can. I now have as much in repairs as I bought the car for.

RJ_RS_SS_350

Hi Stephanie, to the forums!

Sorry to hear that your HHR is sick. The battery would have been our first suggestion also. Another problem that several HHRs have had, with these symptoms, is the underhood fuse block. There is a top half and a bottom half, and sometimes they were not tightened up sufficiently.

You could also check connections, starting at the battery. The terminal clamps can sometimes crack, which is a bad connection. The battery is in the back, in the spare tire well. The positive cable runs all the way to the underhood fuse block, where it is bolted to the side. Another cable also bolts up with it, and bolts up to the starter. Still another cable goes from the starter to the alternator. Any of these points could be loose, or corroded, giving a bad connection.

Another suggestion, take the car to the auto parts store for a free battery load test and charging system test. Post the results here, actual numbers, don't settle for them just telling you "everything is good".

donbrew

If you mean the fuse near the battery it has nothing to do with the ECM; it powers the BCM. Your problem is NOT the ECM; it is power related.

Oldblue

Agreed, there is a possibility the under hood fuse box is the problem .

https://www.chevyhhr.net/forums/how-...rmation-59520/

Have a read through this thread.