Pcm Help

[Altin]

I posted this question on a few forums hopin for a solution. This weekend I finally did the electric fan conversion on my 03 Tahoe. The fan assembly is from a 05 escalade I was told, the headlight wire harness I got myself off a 05 z71 from a junkyard with the pcm as well. While I was collecting the needed parts I also got a new water pump and a 160 thermostat to help cool better. So me and my two buddies started Sunday noon and finished 10 pm. My engine bay looks great now with the e-fans. Problem is the pcm from the z71 is not working with my truck, I was hoping to avoid going to the dealer to program my pcm by using this pcm from the z71 since this one had the elec fans. The truck just cranks but it won’t start, I tried the security relearn process but no luck, I cranked for a few seconds to attempt starting it then left the ignition on for 11 min then repeated this step two more times but still no luck so I put my pcm on and the truck starts fine but fans won’t come on not even with the ac, by the way I had the fans turn on manually. Both pcm's have the same colors on c1 blue and c2 green. My pcm harness is c1 blue and c2 green. The fan wires from the headlight assembly which I got from the z71 that go to the pcm are green and blue. On my harness both c1-42 (blue connector) and c2-33 (green connector) were empty so I put the pins in there and soldered them with the harness. Now if anyone has any suggestions solutions for me as how to get that z71 pcm run with my truck please run it by me I’m all ears, lol. Any input is greatly appreciated

[COWL327]

The PCM has to be programmed...no way out of it

[GasGuzzler]

Yep. Besides that I'm confused on the problem. 10 hours? Why did you swap pumps?

[Altin]

The pump had a small leak once so i didnt wana take any chances with that and it took long coz i took out my headlight assembly harness and put the one from the newer truck with fan plugs and relays

[Altin]

Update. I went to the dealer and asked if they could program my pcm for the efans to work and the counter guy gave me a long story about making an appointment and then they have to make a work order to request a special program from the headquarters so I figured I’d rather have my pcm programmed by an aftermarket tuner if I was gone spend that much and wait so long and I could get some better performance all at once. A guy waiting there told there was someone local that did just that right here in NYC called Pcm performance, so I got the number called the guy and the next day I was by his place where he tuned the pcm and turned on the pins for my efans, now not only my efans are working but the truck drives so much better, the response up shifts down shifts are much quicker redline 6200 rpm’s limiter gone, overall I love the tune, I highly recommend that anyone contemplating about getting it I say do it you won’t regret it, I can’t stop grinning when I get in my truck

[Altin]

Thank you all for all the help

[GasGuzzler]

The dealer cannot enable the PCM pin for efans with GM equipment.

[OBB]

The dealer cannot enable the PCM pin for efans with GM equipment.

OUCH, this is the answer I was looking for. I don't have any tuning software and don't plan on doing a bunch of performance mods to justify buying software. I did however get a set of 05 tahoe fans to put on my 04 Avalanche. I spent the money on a factory harness ($200) and got a few ecm plugs from a junk yard to get the pins I needed.
Does anyone know of any tuners in the Canton, Ohio area that can turn those fans on or should I go with a FAL harness with the temp. probe and tie the high side into my A/C comp.?

[Chevy366]

OUCH, this is the answer I was looking for. I don't have any tuning software and don't plan on doing a bunch of performance mods to justify buying software. I did however get a set of 05 tahoe fans to put on my 04 Avalanche. I spent the money on a factory harness ($200) and got a few ecm plugs from a junk yard to get the pins I needed.
Does anyone know of any tuners in the Canton, Ohio area that can turn those fans on or should I go with a FAL harness with the temp. probe and tie the high side into my A/C comp.?

Personally , I think the PCM pins are the only way go , let the PCM control them they way it was designed to .
Hmmm a Tech2 can't do e-fans , worthless piece of junk then . ;-)

[OBB]

Personally , I think the PCM pins are the only way go , let the PCM control them they way it was designed to .
Hmmm a Tech2 can't do e-fans , worthless piece of junk then . ;-)

I'm waiting to hear back from a tech at a local garage that does some work for me every now and then to confirm this.

Hell, Summit Racing is only 30 mins from my house. Might be time to do some more online research and then a road trip.