PWM cooling fan(s) control using ECM

[andrewb70]

Originally Posted by dontlifttoshift

Doing a Connect and Cruise LSA. Is it confirmed that I can _not_ control the fans with PWM with a GMPP E67?

JP and I have discussed this quite a bit. When he was doing the white LS9 Camaro he had to do all kinds of BS to get it to work. He called GM and got some unclear information and was told PWM is not possible on the GMPP harness kits. This is in contrast to Scot's experience, but Scot's kit is much older.

I suspect at some point GM changed the firmware/OS (pure speculation) to render PWM not functional. JP ended up getting a used E67, refreshing it with a Corvette LS9 OS and was able to make it work.

Hopefully JP jumps in here to clarify, but that's my recollection.

Andrew