Custom 07 Tahoe, Fan System Issues

[smmperformance]

Hey Guys. We are working with a unique project and would like to resolve our charging system issues. The vehicle is a 2007 Tahoe LTZ SUV with a GM LS7 7.0L engine and GM 4L80E transmission.

First of all, see our most recent attached tune file...

We have had the OEM 07 Tahoe PCM & TCM flashed with a new VIN for a vehicle with a 4L80E transmission, for proper operation.

We are having an issue with the fan system. The vehicle has a dual fan system factory. The fans are setup to come on at 100% at the lowest temperature setting possible. We would like BOTH fans to run 100% at all times once the coolant reaches this temperature, all the way up the scale. We have this set properly it seems, but the fans do not respond to our new settings... Any idea why? How do we fix this issue?

I appreciate everyone's help... Please advise.

[5_Liter_Eater]

This is probably due to the fan relay controls. There is a really good thread about gen 4 fan controls in the gen 4 forum somewhere.

In looking at it though it seems to be set up right. I cant' say I agree with the fans being on 100% at 192 as since this is the lowest value the PCM will use this for any temp under 192 as well, but your tables have you transitioning into state 3 at 99% commanded. State 3 has both fans on. Shoot, state 2 has both fans on which should be happening when you command 90% fan.

What happens when you command fan 1, fan 2 and even fan 3 to ON in VCM Controls?

[smmperformance]

What are the difference in fan type? Discrete, PWM, etc...