I just bought this car, its an 05 Cobalt LS.

I get the engine codes P0480/481

Basically with the car off, you plug in the cooling fan relay #2 and the cooling fan(radiator fan) will turn on and run forever.

It will do this when the car is on as well.

Plugging in the relay will cause chatter and it will become very hot very quickly

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I unplugged all connects to the PCM, and plugged in the relay #2 - fan still ran
I bought a new radiator fan and plugged it in, then relay - fan turned on

Had another cobalt guy say he thinks its the PCM, ive had an electrician look at it, and he said he didnt believe it was my fans, turns out he was right about that.

Car has a dmv ten day and needs to be inspected soon

I'm still driving it no problem, fan comes on and im never over 200.


There is obviously a short somewhere?

pull the 30A fuse for cooling fan relay #2 and plug in the relay - no chatter or fan turn on.

PLEASE HELP
this is driving everyone crazy

 

Sounds like your cooling fan relay(s) might be stuck in the on position. Off the top of my head id say replace the cooling fan relay.

 

that was the first thing we did, Checked all three relays and even bought a new one. Took the three wires from the cooling fan and tested each one for resistance and continuity. The wire for pin 43 to the pcm, we checked for shorts - nothing. Found the exact slot with the short, being 4th quadrant. Tried to rig a relay with wires, and to a new ground, fan didn't go on. However on second ignition the car threw a CEL.