My 2007 HHR speedometer not working, transmission not shifting out of low gear, and power steering light on. I changed speed sensor on transmission, no help. With the car on blocks, I checked the wiring harnesses. When messing with the wires around the underhood fuse box, the speedometer would start working and stop working. It is hard to figure out which wires are giving me the problem. Any help with indentifying which wires control this would be helpful. All fuses and relays seem to be good..

 

My guess would be connections at the under hood fuse box ( PDC ). I will try and dig up a wiring diagram for you. There's one in my gallery but I can't get to it right now. you can also look at the posts for factory fog lamps there are some good pic's of the pdc removed.

 

Thanks, will look for pdc pics

 

checked all connections...all seem ok. Something odd hapened when i was checking connections. Car on blocks, engine running in drive, speedometer not working. I pull the run/crank relay and the speedometer starts working, also engine has slight miss. ?????? More confused.

 

relay stuck maybe?

 

Bad fuse box or loose connectors to fuse box.

 

TCM Trans control module Had the same no speedo, no shift, no P/S. Is there a code ? My 06 did but not all the time. If it sat over night on restart it would shift ok and speedo would work. checked code it would say lost communication.

 

Any updates? My 2010 is doing this. Second or third time now. This time was the worst. Took a bit to fix itself

 

This thread died 9 years ago. I wouldn't expect any updates.