Hi All,


New to this forum. I bought a 2009 HHR with the 2.2L recently, it was sitting in a field for the last 4 years or so. The car starts and runs. The transmission connector wires were chewed through and have been repaired. I've just recently found that both oxygen sensor wires have been damaged as well. The oxygen sensor wires have not been repaired yet.


The issue/troubleshooting steps:

Whenever the car is turned off the cooling fan and fuel pump both run and never turn off. I can disconnect the battery overnight, then reconnect it, and the fan and fuel pump will turn back on with the key removed. I've already tested that the key is in the full off position, but the fuel pump and cooling fan still run.

If I remove the fuel pump relay, the fuel pump and cooling fan will turn off.

If I remove the cooling fan relay, the cooling fan and fuel pump will turn off.

Just purchased and installed a used fuse panel from a 2011 HHR, still the same result. Thought it might have been a fried fuse panel. Wasn't that expensive.

If I disconnect the ECU (or whatever Chevy calls it) the fan and pump do not run.

There appears to be no damage to the wiring harness from the fuse panel to the ECU.


I'm almost to the point of purchasing a reman ECU. A quick search on google shows around $350.


Out of ideas... anything else I can check?


Mark

 

you need a wiring diagram. Your issue kind of makes me thing the relays are getting a ground all the time….if it is wired that way. Lot of times the ground for circuit goes thru relay….sometimes the other way around

 

any codes?

 

Look on the underside of the fuse box for green death or shorted wiring.

 

now that's a good idea.
also, I think Donbrew has wiring shematic

 

I was thinking that as well, which was I replaced the fuse panel. Seemed like something was shorted/fried in the fuse panel. After using the replacement fuse panel with different a different set of relays, the issue still persisted.

From what I recall from the wiring diagram, the cooling fan is pulled to ground to activate. The fuel pump relay is activated by putting 12v to it.

The only wiring diagram I have is from AllDataDIY.

I haven't been able to find a diagram for the fuse panel connectors or the fuse panel itself.

 

What do you mean under the fuse panel? Under the fuse panel is a set of 4 connectors. Are you referring to the ground wire going to the inner fender well on the drivers side?

 

Im kind of new to hhr’s myself but I think he means the one under the hood

 

Under the hood there are several ground connections.

 

Any chance the relays got tested? Sounds like one or more of them are stuck on.
Maybe another case of the fuse box needing tightening.
The ECM sends a ground signal to the cooling fan relay. The relay switches 12V from the 40A fuse
The ECM sends a 12V signal to the fuel pump relay. The relay switches 12V.from the 15A fuse.
Doubtful a bad ECM. More likely crossed wires or fried relays. The 2 relay control wires are next to each other on the ECM connector; one is lt green the other is dark green; sounds like a recipe for confusion

The fuse box halves need to be a lot tighter than "hard to turn.".