PATA

I am starting a new thread... hope this is ok.

The ECM fuse does not pop... I went to the computer which is behind the glove box... pulled the ECM and it smelled bad... electrical short. I opened the ECM and sure enough it is burnt.

My question.... If the fuse and other devices are supposed to blow first, why did the ECM get fried? I was told by the autoparts guy that there was moisture in the case which is why it (the ECM itself) shorted out. I can look back and remember when the window was left open and it rained. I purchased a new ECM and it is in the truck and it runs...

Am I at risk that the ECM will fry again? or will it be protected from shorts by the fuse and other devices? I wont leave the window open again....

GMMerlin

The circuit protection is for the power side of the ECM.
The ECM also supplies power and grounds for relays and solenoids..if one of these solenoids is internally shorted, it could feedback to the ECM and burn it up.
Moisture would be an issue if you had left the window,glove box and cover open and it rained for 40 days and nights.
Are you at risk to fry another ECM..if you did not check the solenoids for shorts and did not check the grounds...YES.

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