ECM some times will not exit self diagnostics, only happen when really humid out

[reaper1986]

Really need some ideas as where to check on this one, If it's really humid outside, the ECM will stay stuck in self diagnostics mode, as in the engine light will not turn off and the truck will not run. Now sometimes if I toss the scanner on it, it seems to clear the issue out and everything runs fine until I restart the truck. I just replaced the ECM due to it getting hit in an accident. Seem to run much better after the new ECM was installed. only looking for ideas of what to check, and Trust me if I had the cash for a carb and a single wire distributor, I'd done that a very long time ago.

[painter66]

Did this happen before the wreck? If not you gat a bad conector or wire. That's where I'd start looking.

What vehical?

[reaper1986]

turned out parts place gave me a bad ECm from the factory, replaced with a different ecm from a different parts supplier, (MAZZA) and so far have had no problems.

[painter66]

Can't trust anyone these days. How are you to figure a brand new part is junk?