On my 2009 hhr, I replacement the heater core this past weekend. I did some reading and it told me to disconnect the battery for the airbag. After everything is said and done I went to start it and now I'm getting just about every error code. How can I reset the computer and should have I done something different. Thanks for all your help

 

Disconnecting the battery resets the computers. For safety you should disconnect the Ground.

You must have inadvertently jiggled the underhood fuse box. OR, you are getting a few error codes that would tell which wire got mangled.

 

Welcome to the site, check the ground wires, check the battery ground.
Disconnect the battery for the time you are checking those, then reconnect the battery.

 

Does it actually run, or turn over but not start, or what - help us out here?

Since I can't believe it had all the codes possible, just what are the codes you are getting?

In replacing the heater core, what procedure did you follow in replacing it? Was it one you found here?

 

It does start, messages I'm getting are service airbag, ESC, traction control. Info was not from this site.

 

Did you by any chance remove the front of the "waterfall" and disconnect the warning lights?

The connectors look alike and get reversed.

 

i check and there are set right.

 

I went by my own now which and what Chilton had in there book. Cannot find how to replace heater core anywhere i looked

 

Did you label the connectors; is that how you are sure they didn't get switched?

I know that was the solution to the last member with this exact problem, last month. He had replaced the radio.

Strange how those 2 lights are lit after doing unrelated work, if the wires are right.

 

Here is a thought. Can the gas pedal sensor connector would that throw the reading off? I'm asking because it was pulled and maybe a wire came louse