ECM power supply lost with ignition turned on...

[Meatbag]

(02-15-2018 )Signature620 Wrote:  I usually see 1117 caused by:

- Weak batteries as explained by ZeroNTheDark
- High resistance between batteries and the 4 pin connector @ ECM
- Drivers turning off the battery isolator as soon as they turn the engine off.

Anything that effects unswitched power to the ECM or disrupts it's powerdown cycle will give this code.

That is a good point about the weak batteries, at this point I don't remember if I load tested them or not. They are over 2 years old and the heat out here (Phoenix) is pretty tough on batteries, might as well replace them and hope for the best. After I replace them I am going to ohm test the supply harness again just to make sure. Wiring drives me insane lol...