PWM cooling fan(s) control using ECM

[parsonsj]

Originally Posted by Dave

Not true - it's in there. Main change was to make controller incompatable to use (with GMPP software) in a production vehicle - so you can't defeat theft systems.

I wish you were right!!

I spent a month with a GMPP LS9 (E67) controller trying to get the fans to work. HPTuners happily let me make the changes to the fan tables, but the PWM control wire didn't have a signal. I finally opened a support case with GMPP, and tech support told me that fan control (and AC pressure, and reverse logic, etc.) was deliberately disabled in the GMPP E67s.

I switched to a salvage yard E67 from a V6 Malibu and got that working immediately (wrote ZR1 OS, then copied the GMPP tune plus the fans).

I even documented my journey in this very thread a few pages back.