eFan Running All The Time

[Level2]

I have a 2001 Suburban here, 6.0L with eFans installed and relays operating correctly (testing with ground wires, they power on/off perfectly). Trigger wire from pin 42 is being used, as per all articles.

The issue is when turning the ignition on, fans do not run, but ONCE the car is started, they come on in 5 seconds.

PCM Serv. No. 12200411
HDW NO. 09386530

I see some posts about this from long past, but nothing that ends in a solution.

Anyone have any knowledge on how to fix this?

[minytrker]

Either post your tune or a screenshot of your fan settings.

[Level2]

Thanks to JoeCar, this is the fix for it:

Goto www.tunefiledepot.com and find a 12212156 tune file under Stock Tunes->Chevrolet->Gas/Petrol and download/save it.

Then edit this file, copy all the tables from your file into this (open 2 instances of tunetool, copy each table, one-by-one, use copy-with-labels/paste-with-labels), then save as (and let the tunetool add an incrementing number on the end of the filename)... and then full=flash this into your 0411 PCM.

[Chuck CoW]

Thanks to JoeCar, this is the fix for it:

Goto www.tunefiledepot.com and find a 12212156 tune file under Stock Tunes->Chevrolet->Gas/Petrol and download/save it.

Then edit this file, copy all the tables from your file into this (open 2 instances of tunetool, copy each table, one-by-one, use copy-with-labels/paste-with-labels), then save as (and let the tunetool add an incrementing number on the end of the filename)... and then full=flash this into your 0411 PCM.

Very good.... Just tried to install e-fans on the 2001 Yukon XL w/ 5.3 and it won't work in just the same way.

What is the significance of this os, versus another or is there a system segment # we need to swap in?

Thanks
Chuck CoW

[joecar]

I think Level2 is saying (from an old post of mine) to change to a truck OS that supports e-fans... I'm not sure about e-fans.

[minytrker]

On a ls1b pcm you can just turn on the fans, the easiest way to is to copy and paste the setting like Joecar recommended. Now this only works if you wired them up like the factory did with 3 relays and used the 2 pins in the pcm. Depending on the year vehicle you're trying to add the fans to one of the pins may already be used.

[Chuck CoW]

On a ls1b pcm you can just turn on the fans, the easiest way to is to copy and paste the setting like Joecar recommended. Now this only works if you wired them up like the factory did with 3 relays and used the 2 pins in the pcm. Depending on the year vehicle you're trying to add the fans to one of the pins may already be used.

Here's what I found.... With the original calibration fans would not work, so I was uncertain about switching to another OS for fear

I'd pick up other problems in the process... By simply switching to the LATEST gm OS, the problem was almost fixed..... They would come on

but not turn off at the low fan cut point.

SO, having the e-fans in my tahoe for many years, I copied the calibrations from my tune and still nothing. The Aux fan setting that I use in my

truck (which works perfectly for years) would not work on my friend's truck, but changing to series parallel fans it worked fine.

Over the years I have discovered that it is OS dependent and the same calibrations don't always work in all cases.


What I was actually asking was if there was some secret OS that you needed to use or if there was some logic to the

OS that Joe was recommending..... I'm sure GM didn't put out this OS upgrade to help guys like me put E-Fans in their

trucks.... I just got lucky that this OS and system segment work together in the way I was expecting....

The second FAN control pin was robbed by GM to operate the re-circulate door for what I believe is the fresh air inlet to the heat/AC.

I never really looked much past that, but I've always felt that since doing the e-fan on my truck many years ago I think the

fact that I changed the fan operation cals, the recirc door always stays open.... I'm pretty sure I accidentally changed the

function of the recirc feature by switching to "no fans".

Can anyone out there confirm my suspicion? It's been no big deal, but I'd rather have the e-fan either way....

Chuck CoW