e92 2015 5.3 fan control question

[modularfox]

Is it possible to have the e92 ecu control a relay like the GEN3 ecu did? The searching I found says to use discrete and the notes about discrete (in HPTuners) says to have it on 128hz. From the schematics, connector x105, pin 1 shows circuit 473 and that is the fan "High Speed Cooling Fan Relay Control" but no relay for the stock truck as they are its pwm. I was wondering if its possible to have it provide a ground output and control a relay? or is it only possible to install a PWM capable fan? I've connected a volt meter to it and one lead to ground, one lead to circuit 473 and its around 3.4v. When I connected circuit 473 to the relay for ground control, the relay clicked repeatedly like it was being PWM ground.
Any help would be appreciated.

The L83 is going in to my 1987 Silverado square body short bed



This is my 3rd l83 wiring swap harness I've built, but haven't gotten the fan to operate through the ECU. Other 2 swaps a radiator temp sensor was used which activated the fan relay

Thanks in advance,
Clint

[modularfox]

Just in the stock tune file is needed to roam around, stock file attached.
Thanks,
Clint

2015 stock.hpt

[veee8]

Did you change any of the Relay controls settings? State VS. Desired and Output VS. State? Also Desired ECT Fan control.

[modularfox]

Thanks for the reply, I didn't change either. The state vs desired - wasn't sure what that the different states were. I was testing it by changing only fan type to discrete and fan PWM freq to 128, wrote calibration, and performed the component activation from the vcm scanner.
Thanks
Clint

[veee8]

Here is a spreadsheet for Gen 4 Discrete fan settings. You may be able to apply some of the logic to the Gen 5. A few of the tables are a little different, but should help you in getting the settings you need.

Discrete Fan Turn On Temp Settings v2.2 temp .xls

[modularfox]

Appreciate the spread sheet and for taking the time for helping me. I will play around with the chart and fan settings and post the results up. Thanks again veee8.
Clint

Here is a spreadsheet for Gen 4 Discrete fan settings. You may be able to apply some of the logic to the Gen 5. A few of the tables are a little different, but should help you in getting the settings you need.

Discrete Fan Turn On Temp Settings v2.2 temp .xls

[chuckk]

Mine is staying 3.4V all the time. Haven't found the fix for it yet.
The scope shows a regular 3.4v line, did not look like a pwm signal at all.

[Randallkreed]

Appreciate the spread sheet and for taking the time for helping me. I will play around with the chart and fan settings and post the results up. Thanks again veee8.
Clint

modularfox, I realize this thread is a year old now, but where you able to get the discreet fan setup working with the E92 ecu? I am finishing up a build and have reached this issue. I've done this with a Gen 4 setup before but the tables in the E92 for fan control are totally different. Plan B will be a thermostatic switch but I'd like to get it set up for the ecu to control it.. Thanks for any help you can provide

[modularfox]

I have not, I gave up and just retrofitted a stock BMW fan (that's PWM) to a shroud I made for the stock radiator. Having problems with the ECU commanding 89% and staying there. I have a separate post about that one though.





clint

[vannatta20]

The e92 will not activate a relay from everything I have tried. The only way is to use a gm performance calibration. That can cause different issues. Here is a video showing an option to make it work

https://youtu.be/hI5Sp9neD2c