Intermittent WARN ENG light '01 9400 12.7

I've been getting an increasingly frequent, but still intermittent, "warn eng" light on my 9400. Typically it occurs right at the crest of a hill as the engine is coming off load (and as your stomach rises in your chest). It'll come on for a few seconds, then turn off. Often I'll smell a faint odor of burning electronics from the dash shortly after it occurs.


Flash codes are 31 ( Aux. High Side Output Open Circuit or Short to Ground ) and 43 ( coolant low ).

I believe both of those codes are old (I never fixed the code 31, but definitely took care of the code 43 with a new coolant sensor).



When the light is actually illuminated, the scan gauge will detect a trouble code:

1...52...03...17

"1" is the 1st code stored in the scan gauge.

"52" is the diagnostic trouble code (ECM A/D Conversion Fail???)

"3" is the failure mode (voltage above normal or shorted high)

"17" is the number of times the code has been triggered.


I've peaked behind the switch panel (where I'm pretty sure the smell comes from), but I can't spot any obviously burnt wires or connections. Jiggling various wires with the engine idling does not trip the light.

What should I do next? If this intermitten fault were to fail permanently, what problems could it cause?


@Heavyd

 

Ah! that makes sense. My mechanical odometer has also recently been hanging up so I'd been relying on the scangauge ecm odometer.

 

Pretty sure I found the problem -- a shoddy installation of an aftermarket fan switch. Dunno how it got analog/digital out of that, but the orange light seems to have gone away after re-wrapping a chafed wire