Need Efan help for 2008 Trailblazer SS

[Sneakyws6]

Ok here is my deal, I got a wiring harness and a set of LS1 fans (dual setup)

The ECM patch I got from the vendor is not working as it seems the 2008 TBSS uses the E67 ECM that did not have Efans on it from the factory. He set the Efans in the ECM to "PWM electric" with 3 fans even though there is only 2 fans but they are wired to seem like 1 fan thru two relays that start 1 first, then 10 sec later the 2nd fan comes on. I was instructed to use pin 49 on the J3 connector on my harness. That works as far as I can tell as I can trigger the fans tru the VCM scanner at least.

I have found the fans will only work if set to "Discrete" in the fan settings at least. If they are left in PWM mode only one fan will come on and it will pulse badly.

I need to know what I have to do to get the fans to come on at the lowest setting (192 I know this much) and run at 100% for the entire time they are on. I have a 160 thermostat in the truck and would like to stay in the 170 range or so, but so far I am stumped on this. Anyone got any ideas?

At the moment I am not worried about key off fan opertation, only key on and with or without a/c operation.

Here is the file I was sent and the one I have in right now. Any help would be greatly appreciated. Otherwise I am going to have to go old school and use a switcha nd relay to control this setup which I dont want to do as i would rather have the ecm control the fans.

Thanks...Todd

[WarWagon]

I would get ahold of Alvin, he knows what he is doing and generally gets back to you to answer questions. He also takes the time to answer all of your questions.

Sounds like you want a lower temp then the factory ECM will handle. Your lower fan on temp limit is 192. The E40 2.5 bar custom OS would rescale the fan temps - if you had a 2006... I would leave a 0 in 192 and start the settings at 196 and warm then engine up to 196- just to test it for working properly. Sometimes a computer will freek if the bottom of the scale is at the max. You can also turn on the AC and see if the fans kick on - by the kit design.

The E40 and E67 ECM on the TBSS did not have efans from the factory. Yet, the E40 ECM runs efans on the GTO and Corvette. The E67 ECM is on the 2007+ TBSS and the fans work as far as I hear, but the setup is different than the E40 ECM.

If you want a lower temp range you will have to do something else like a hard wired temperature sensor etc. Problem is at 30MPH+ electric fans are useless. (And unless you are towing a big trailer, fans are generally not needed at speed.) The airflow over the radiator exceeds the CFM of the electric fans quickly. Think of 2 square foot of radiator at 60 MPH, number of feet in a mile 5280 =10560 CFM at 60. The CFM of the efans tops out at around 5000CFM. This is why the clutch fan takes so much power to run - working above 30MPH to deliver over 10,000CFM in extreme high load, like mountain pass trailer towing with high air temperature ,110+ degrees, conditions.

[Bill@HPTuners]

The 08' pcm calibrations are setup differently than the 07's For now I think the only solution alvin has been able to come up with is flashing in an 07' operating system into the 08's. We are working with alvin to come up with a more permenant solution on them.

[99blackFRC]

I'm using a 2005 TB 5.3L engine in my Jeep swap which was originally set up for the OEM clutch fan. Of course, in my case this is using the E40 ECM, not the E67. Either way, for me to switch to Efans, I just had to change the fan settings to Discrete instead of PWM EV. I also had to set the fan tables up of course. I think I just copied the GTO settings.

[Sneakyws6]

I tried GTO tables as I had a GTO before the TBSS, those didnt work nor did any of Alvins tunes he has sent me.

At the moment I am a test subject on tis which I dont mind but I need the truck to drive to work and Alvin has a car show this weekend and probably will not have enough spare time to help me out right now.

I dont want anything lower than the ecm either, but I do know that without a PWM module there is no way a set of LS1 fans are going to work if they are set to PWM Electric in the ecm, this has been confirmed already by me several times.

Also none of the tunes Alvin has made up so far have worked, with or without A/C. They truck got all the way to 210 degree last night and they never came on.

Any other suggestions, I am not trying to go around Alvin but the more hands and or suggestions that can help me get the fans on the better. Right now I have the fans on a manual switch, I plan on ordering a controller today just in case there ends up being no other solution to the situation,

I cant have the 07 OS loaded into my ECM as it will lock me out of the ECM which will render my HP Tuners useless.

[99blackFRC]

If nothing else is avail right now, the stand alone controller would be my recomendation as well. They're relatively cheap and can be pulled back off once the ECM solution is available.

[04colyZQ8]

is it possible to add computer controlled fans to a 2009 Colorado 3.7L e67 pcm? I see e-fans in the tables, iff i put one fan instead of zero will it work off pin 49 c3?