PWM cooling fan(s) control using ECM

[Coursey]

Originally Posted by vannatta20

A 5th gen camaro e38 os will not support pwm. But a truck e38 os will. Also the e92 silverado controller will only support pwm at 100hertz. No discrete on the new stuff factory os.. The gmpp e92 controller will support discrete only. Its all super confusing and testing is the only way to know for sure. Lot of misinformation out there. I use an oscilloscope at work to see the signals. To get ac control the computer needs to get a serial on request from the bcm. We have a module the sends that signal along with tap shift commands for gen iv and gen v. This control the fan based on ac pressure as well. Works perfectly.

Originally Posted by andrewb70

I'm pretty sure you don't need the controllers with the brushless fans. They have everything built into the motor controllers, so you just need to provide power, ground, and a PWM- signal. Presumably the PWM- should be configured the same as with a C6 controller. This is somewhat speculative on my part.

Andrew

So will the 2015 Camaro ECM put out a PWM signal?

Be great if it can go direct to fans with no control super simple that way.

[andrewb70]

Originally Posted by Coursey

So will the 2015 Camaro ECM put out a PWM signal?

Be great if it can go direct to fans with no control super simple that way.

I do not know. I am not that familiar with the intricacies of the OEM ECUs. I'm sure someone will chime in.

Andrew

[dontlifttoshift]

Yes, control wire will go directly to the fan, no controller needed. You will have to change the frequency to 100hz for the spal fan instead of the standard 128hz that GM runs.

I may have that backwards, but there is a post in this thread regarding the frequency that the Spal brushless wants and it wasn't the same as GM.

[Coursey]

Originally Posted by dontlifttoshift

Yes, control wire will go directly to the fan, no controller needed. You will have to change the frequency to 100hz for the spal fan instead of the standard 128hz that GM runs.

I may have that backwards, but there is a post in this thread regarding the frequency that the Spal brushless wants and it wasn't the same as GM.

Thanks,

I just want to confirm that you are talking about using the 2015 Camaro e38 ecm.

[dontlifttoshift]

Can not confirm E38 and I honestly missed that part of the question.


Unrelated to that but relevant to the discussion, I got confirmation yesterday that Godspeed was successful with the PWM control on the E92 ecu with his GM crate LT4.

[andrewb70]

Originally Posted by dontlifttoshift

Yes, control wire will go directly to the fan, no controller needed. You will have to change the frequency to 100hz for the spal fan instead of the standard 128hz that GM runs.

I may have that backwards, but there is a post in this thread regarding the frequency that the Spal brushless wants and it wasn't the same as GM.

Donny,

The genIV ECUs and C6 fan controller want 128Hz. I don't recall anywhere in this thread where 100Hz was called for, but I may have missed it. It would be great to get a definitive answer on this, since I am primarily interested in making the Holley Dominator work with the new Spal fans and I can easily change the frequency.

Andrew