ECU Connector J1 Pin B17 / 2009 Cobalt 2.2L NA 5 Speed

[Doug Rostad]

I currently have a 10 amp fuse graveyard at one end of my garage

 

[Gtstorey]

Ross
Yes , Ebay loves me! at first I thought, ok maybe I tightened the fuse box connectors to tight. I ordered on,,, It was going to be a few days longer than I was willing to wait to move foreword..... so I ordered another one closer to me. Once I got it I took my original one apart,,, checked the board, Nothing wrong with it. but, it was an interesting experience. Then, to eliminate anything I bought a BCM and an ECM to try to eliminate the issue. Still to have the original result. Now with every engine plug disconnected, Brake plug , clutch plug disconnected. to get to what I see to be connection "E4" in the black fuse block plug,,,, that is to be supplying B+ Power to the ECM from "E3" from the BCM to be a dead short to ground. That red and white wire is 12" long and in plain sight to not be bare and connected to ground.
I was so frustrated with it last night I spent my garage time fabricating front and rear bumpers for the car , instead.

What do you mean by engine plug disconnected? Does it shoot the fuse with ECM with the ECM X1 plug disconnected.

 

[Doug Rostad]

If it's popping a fuse when the ECM is plugged in but not popping with it unplugged, it gets a lot harder to point it to wiring upstream of the ECM. Not 100% impossible it's in the connector. Has this connector ever been apart?

No , neither of the ECM connectors have ever been apart

 

[Ross]

Hopefully your bumpers helped get rid of that frustration.
You are making progress!
We know that E3 going to the ECM is dead short to ground. That red and white wire is 12" long and in plain sight to not be bare and connected to ground.
Is this true with the the ECM unplugged?
If true, then your wiring is good, and the ECM is bad.
If the fuse only pops with the ECM plugged in, then the issue is something to do with the ECM or its sensors.

 

[Doug Rostad]

What do you mean by engine plug disconnected? Does it shoot the fuse with ECM with the ECM X1 plug disconnected.

I have every plug disconnected from the engine , to eliminate it from the results. None of the ECM fuses blow. Only the BCM # 25 fuse blows. That is when I traced the red and white wire from the BCM to the square black connector in the fuse box. By the schematics it just jumpers E3 from the BCM (by the diagram attached) to E4 going to the ECM. With the battery connected and all of the plugs in the BCM and the ECM if I connect E3 to E4 the 10 amp fuse in position 25 on the BCM blows

 

[Gtstorey]

I have every plug disconnected from the engine , to eliminate it from the results. None of the ECM fuses blow. Only the BCM # 25 fuse blows. That is when I traced the red and white wire from the BCM to the square black connector in the fuse box. By the schematics it just jumpers E3 from the BCM (by the diagram attached) to E4 going to the ECM. With the battery connected and all of the plugs in the BCM and the ECM if I connect E3 to E4 the 10 amp fuse in position 25 on the BCM blows

Giving the entire story doesn’t really help. Does the fuse blow with ECM connector x1 disconnected?

 

[Ross]

I agree with Gtstorey... the next test is to unplug the X1 connector from the ECM, then test if the problem is still present.
That will tell us if the problem is in the ECM or in the wiring harness.

 

[Gtstorey]

Your fuse box connector doesn’t match the service manual so I don’t know that you are jumping the correct terminals. At least a lot of your colors don’t match. You have to pay attention to the mating stubs on the outside of the connector to orient it correctly. And this is looking at it from the top side, not the wire side.

 

[Gtstorey]

A little more studying of wire colors shows that you have them numbered backwards but since 3/4 at in the middle they are the correct terminals. But this calls into question what else you have backwards/wrong.