ECM fuse popping.

[clayton191]

Hey everyone,

I have a 2015 GMC Yukon 5.3 SE - I have been getting a blown 30Amp ECM fuse every time I turn the ignition on. There are three connectors to the ECM. If I disconnect those, insert a new fuse, and turn the vehicle ignition to ON, the fuse does not blow.

Does this sound like a bad ECM? or should I diagnose further (aka, could the fuse pop if I have a ground on an O2 sensor thats connected to the ecm)?

If it is a bad ECM - What is required for me to get a new ECM? Just show up at the dealership and buy one? Do they need to be reprogrammed.

I do a lot of shade tree work on old jeeps but this may be beyond me. Just trying to avoid having it towed....

 

[ReaperHWK]

Sounds like a short somewhere. I’d turn the car on with each connector connected one at a time and see which one causes the fuse to blow. Then I’d meter each pin in that connector to groind and see which one is shorted.

 

[swathdiver]

New ECM has to be programmed to the vehicle. If you have her towed in, let them diagnose the problem and they will apply that fee to the repair.

 

[clayton191]

Sounds like a short somewhere. I’d turn the car on with each connector connected one at a time and see which one causes the fuse to blow. Then I’d meter each pin in that connector to groind and see which one is shorted.

So it is the middle ECM harness (not blue, not grey, the black one) - I've tried to find the wiring for that module in the diagram. Not having much luck, the wiring doc is 1295 pages haha. Eventually I'll find it I suppose - does anyone know off hand what I could connect?

I read from the ground pin on that connector to each pin hole - and I had an OL for each one.

I appreciate the help guys, sorry for the slow response, I tossed my hands up and left if for a few days....

 

[swathdiver]

So it is the middle ECM harness (not blue, not grey, the black one) - I've tried to find the wiring for that module in the diagram. Not having much luck, the wiring doc is 1295 pages haha. Eventually I'll find it I suppose - does anyone know off hand what I could connect?

I read from the ground pin on that connector to each pin hole - and I had an OL for each one.

I appreciate the help guys, sorry for the slow response, I tossed my hands up and left if for a few days....

Are you using the shop manual at AllDataDIY?

 

[clayton191]

Are you using the shop manual at AllDataDIY?

No, but I will check it out - I downloaded the one off the GMC site for 3rd party / aftermarket installers...

 

[swathdiver]

No, but I will check it out - I downloaded the one off the GMC site for 3rd party / aftermarket installers...

It's worth it. Been using them since 2006 myself.