Quote Originally Posted by Six_Shooter View Post
No, bad checksum will not brink an ECM, at least not OBD1 ECMs.

No, checksum is only updated when the bin is saved. This is why checksum needs to be disabled during emulation.

So are you saying that it runs on base timing, but not when timing is being commanded by the ECM?
Correct. that's what I believe is occuring. Where I'm getting confused is this happens regardless of what bin you use. Even a factory unmodified bin that never hits tunerpro, just straight to the prom, gets you a flickering light.

Same with emulation. The one exception; in beginning an emulation session, disabling checksum gets you no CEL, but what I perceive as the base timing only issue. With the flickering light, you don't even get the stumble.

I've got WB02 wired in, otherwise a fairly solid/stock wiring harness throughout the car. I would blame my chip burner, seeing as how you get the issue bypassing TP, but I can't get through with emulation either.

Possible electrical? what would (if anything) invoke this ECM behavior if it electrical and not in the bin/hardware?