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I ran into this issue last weekend trying to help a friend and finally figured it out after countless hours and wasted $$$ on over night shipping, and licenses attempting to resolve the issue.
We used a 3 relay style harness from PCM of NC with trigger Pins in Blue 42 and Red 33. Pin location Blue 42 requires you to poke a hole through the rubber seal in the cavity. In my case Red 33 was already populated and the pin/wire needed to be removed and taped up out of the way. The fan harness I purchased also required a trigger to be taped on the AC circuit under the main fuse box in the engine compartment.
We used the larger factory style 34" radiator and E-fans from a 2005-07 classic truck.
Symptom: Even after enabling all the E-fan settings in the 99 operating system, The E-fans turn on as soon as you start the engine, even though the engine is still cold. You can control them with the Bi-directional controls on the scan tool correctly, but they always come on right after engine startup and will not turn off on their own.
We had to use a 2002 Truck OS 12212156 and do a Full Flash for it to work correctly on a 99 truck.
What do I have to change on the 12212156 OS ???
You need to enable the Fan settings from No Fans to Parallel Series Fans And adjust the parameters as needed. You can use 2005-07 classic Silverado Fan settings as a base and adjust to your liking.
Under the AC parameters settings, you need to change it from Auto Recirculation to Fan #2.
Aside from enabling the E-fan settings, and AC settings. You need to change a few things in the OS to avoid a false check engine light.
The 99-00 only use the L terminal for charging. You must disable the F terminal in the Vehicle Platform settings. You also need to change the corresponding DTC and Mil settings for that so they match and you don't get a false check engine light.
You may also need to reprogram your original VIN after flashing in the newer OS. Just a Fair warning, some Vehicle inspection process and Smog inspections are required to read the Vin from your PCM as part of the OBD2 testing to make sure it matches the Vehicle being inspected.
***I am not a professional tuner Nor will I take responsibility for how you set things up on your vehicle. It's your responsibility to insure Your vehicle is set up correctly and in compliance with any local, state, or federal Laws.***
I will post up the factory base tune file I used in both EFI Live and HP Tuners format. You will be responsible for setting it up properly by enabling the fan settings as listed and making sure the Vin is set correctly if it's required for emissions testing or vehicle inspection in your area.
***Again, I am not a professional tuner Nor will I take responsibility for how you set things up on your vehicle. You will be responsible for setting up the tune file for your needs including the fan settings, Mil settings for charging system, and Vin change if required for Vehicle inspection or Smog program in your area***
Because I know someone will ask, What about an 03-04 Not originally equipped with E-fans?
All you need to do is purchase a harness of your choice, E-fans of your choice and possibly a larger radiator depending on how you decide to do your swap.
Then you or your tuner can enable the fan settings in your PCM as listed above. You can use the base settings from an 05 operating system as a start and adjust to your particular set ups liking.
Last edited by 1FastBrick; 06-13-2016 at 09:22 PM.
I know it says 5.3 but will 12212156 OS work for 6.0 with 4L80E or am I in search of another OS? New to the HP-tuner scene. I suspect it's install new OS then copy over my tables.
Last edited by ivan DeSlayer; 06-13-2016 at 08:26 PM.
Reason: Cause spell check wasn't me friend.
Yes, You can copy over your tables and do a segment swap with in HP Tuners for the 4L80E
I would have to look for a stock 6.0 File if I even have one.
Got ya covered. Guess I won't be needed to segment anything. I'll need to find out whether I gotta spend the credits to make it happen. Thanks again for the help. Been a pain in my side for a season now.
Got ya covered. Guess I won't be needed to segment anything. I'll need to find out whether I gotta spend the credits to make it happen. Thanks again for the help. Been a pain in my side for a season now.
Unfortunately with HP Tuners, you will likely have to license the new file to the ECU you want to flash it to.
I suggest adding in a delay on Fan #2 to help from burning up wiring and/or relays... I noticed that if all the conditions were set to turn both fan 1 and 2 on at the same time the load the fans pulled was like 20+ amps (measured with a clamp meter) with the 05+ efans. I would burn up a relay every 6 months. That delay allows fan 1 to turn on and get the fans up to half speed, then fan 2 kicks on and the fans don't draw as many amps since they are allready turning..
03-29-2015, 04:11 AM
DIY 99-02 Efan Swap Tech Info
