Code for low voltage to ECM

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TahoeInTexas

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Hello everyone. I have a 2014 Tahoe and I keep getting a code for low voltage to the ECM. I haven't worked on it in a couple of weeks now. I remember checking the B+ and ground wires along with I think 3 ignition power wires to the ECM. In the morning, the truck will start and run fine. Once it's warm, if I shut it off, it will crank, but not start. After cooling off, about 10-15 minutes, it will start right up again. During my troubleshooting, I found that if I disconnect the power wire connector from the ECM after shutting off a warm engine and reconnecting it right away, it will start right up. Another issue is that after a couple days, the battery will be dead and it will need a jump. Battery has just been replaced and same thing. With key off, I backprobed ignition power wires at ECM and found 6.5V coming out of the ECM. Atchison point, I was convinced I had a bad ECM. Replaced and programmed a new one from GM and the same thing. I'm stumped.....any advice on this?
 

swathdiver

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Hello everyone. I have a 2014 Tahoe and I keep getting a code for low voltage to the ECM. I haven't worked on it in a couple of weeks now. I remember checking the B+ and ground wires along with I think 3 ignition power wires to the ECM. In the morning, the truck will start and run fine. Once it's warm, if I shut it off, it will crank, but not start. After cooling off, about 10-15 minutes, it will start right up again. During my troubleshooting, I found that if I disconnect the power wire connector from the ECM after shutting off a warm engine and reconnecting it right away, it will start right up. Another issue is that after a couple days, the battery will be dead and it will need a jump. Battery has just been replaced and same thing. With key off, I backprobed ignition power wires at ECM and found 6.5V coming out of the ECM. Atchison point, I was convinced I had a bad ECM. Replaced and programmed a new one from GM and the same thing. I'm stumped.....any advice on this?

This is usually a battery problem. How old is the battery? Any possibility that critters are munching on wiring?
 
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