$8D (AUJP) Fan Enable/Disable Temperature Logic

Have found the culprit it the Fan Enable/Disable temperature logic of the AUJP $8D code. It appears this code was developed with the thought that no one (except me) would ever set the Disable temperature >= the Enable temperature (while testing or otherwise).

Bottom line, if you do so, the fan(s) will run, but not at full speed because they are constantly being turned on and then off every 200ms. Seems they would have programmed this differently, but at the time they probably assumed no one would ever be changing such values – but it’s still not good coding.

FWIW - Attached are Fan 2 flow logic documents highlighting the issue. Fan 1 is identical to Fan 2 except for Fan 1 run-on times which do not apply to Fan 2, as those values are set = 0 in AUJP.

See here for other details:
http://www.gearhead-efi.com/Fuel-Inj...in-F8-Question
http://www.gearhead-efi.com/Fuel-Inj...nd-7730-Pin-F8

Thanks again for sharing your great work! :thumbsup:

I copied this post to the $8D information thread! :happy:
http://www.gearhead-efi.com/Fuel-Inj...Information-8D