PWM fan outputs in E38 ecm

[87skier]

I'm looking for some information about the PWM output from the e38 ecm and similar. I've seen other people use the corvette PWM controller, but I'm thinking I have something else that will work. In order to use it though, I need to know what the ecm is actually outputting.

I know the discrete fan control supplies ground to turn on the relay. Is this controlled in the same way? Where the computer is just interrupting the ground on the control signal?

Alternatively, if someone knows how the corvette pwm controller's work, that should be the same.

I would investigate this myself, but I don't have an oscilloscope. Any help is appreciated!

[Grip]

http://www.hptuners.com/forum/showth...light=LS2+fans

There is a sticky on this topic. I believe you will find the answers you seek in there. Good Luck!