PWM cooling fan(s) control using ECM

[eville]

Originally Posted by andrewb70

Geeks-R-Us...LOL

In all honesty, PWM fan control adds a great deal of refinement out our old cars. The information from this thread allowed me to implement it on my Cougar build and it truly is AMAZING! On my GTO, I am using dual Spal fans with binary fan control. The car has a relatively quiet exhaust and when the cooling fans turn on, it sounds like a jet engine.

On the Cougar, I never hear the fan, ever, and I have yet to see it go much above 50% duty cycle even on hot summer days. The C6 fan is rated at 400watts, while the new 6th gen Camaro fan, I believe is 800watts! So yes, amazing.

Andrew

I hear that. I'm running the dual SPAL fans on my car and with traditional relays the fan noise is very loud even with a loud exhaust and the shock to the charging system when they're switched on is significant.

I'm anxious to get the PWM setup once I get my Terminator installed and running.

Modern refinement is really what distinguishes some of these builds.

Keep the info coming. It's AMAZING. Lol

[Schmelson]

Originally Posted by vannatta20

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.

What module do you use? BCM?

Doing the PWM conversion. Would like to get the A/C fan request working.

[Coursey]

Originally Posted by blake-b

Has the E38 been figured out for PWM fan control?

I have a 2010 Camaro and a radiator coming with twin Spal brushless fans. I called Spal and they wouldn't tell me anything because of an NDA with GM as they are an OEM supplier. I called the place building the radiator and was told the same thing but they'd see what, if anything, they could find out because they have not installed in a 2010 Camaro.

Dave Steck (DSX Tuning) is a friend of mine and I contacted him about it. He said the Corvette and Camaro E38 OS are the same but have differing CANbus communication. He said he sees no reason I can't control the fans with PWM because the OS has PWM Electric as a choice. That is a screenshot of my actual tune showing it.

Unless I missed something in this thread (quite possible) I haven't seen anyone successfully running PWM in a 5th Gen Camaro and an E38 ECM.

It would be nice to be able to just drop the new fans in, connect the wires and go.

ETA: I don't know which fans I'm getting as the place (wizard cooling) is going to use the biggest ones that will fit. 14" diameter and 3. 25" thickness was mentioned. I am not aware of any other aftermarket 5th Gen radiator having 14" fans though.

Was you able to get this working?

I am installing the following setup in my 1976 Blazer.

L99 DOD delete with 6l80e from a 2015 Camaro

I have 2-12" Spal Brush-less fans part numbers 30107087 VA89- ABL320P/N-94A

I also have vintage air.

Looking at the wiring diagram for the brush-less fans it appears that they do not run throw a relay. It says to just install a 40 amp Maxi Fuse.


I am wanting to hook these up to run PWM so that they are variable speed like a new car. I would like the fans to be controlled by my e38 ecm. I am also installed a pressure transducer on the ac line.


With the 2 fans do i need 2 controllers?

[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

[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