New PCM, A/C won't work and it's 104!

[puddlestomper]

I replaced my PCM with a salvage unit, and now my air conditioner won't work. I can activate the the scan tool and run it with the command button on the diagnostics. I thought I saw a thread on here that dealt with this, but I can't find it for the life of me and its 104 degrees out.:cussing:

[THEFERMANATOR]

Sounds like your ECM(LB7's don't have a PCM) has the wrong operating system loaded in it. This is a common issue when you mix and match tunes, and is why you must use the stock base file for your truck.

[puddlestomper]

I have no stock base file. My computer was locked when I bought it. Had it unlocked and they had to change the OS. And it came back damaged.

[killerbee]

If you are needing a new ECM, we can supply one with your stock file.

[puddlestomper]

I actually considered you and was about to call. Your prices were very appealing. However, a local salvage yard I go to frequently gave me one for $200 with a warranty.

[killerbee]

Glad you got it worked out!!

[puddlestomper]

Sort of. Still no a/c. When I get a new license so I can tune this ecm, is there any way to program the a/c to work properly? Or do I need to search for the proper OS?

[THEFERMANATOR]

You need to find the correct OS for YOUR truck to go into the replacement ECM. Some guys can take your VIN and send you the base file, you could go to GM and have it flashed to get it, OR you could go to the TIS site and find what segments you need and then find a matching tune online.

[puddlestomper]

I've got it. Found a program with the right OS. Unfortunately it's a 215 hp tune.

[GMC-2002-Dmax]

PM me your VIN# and email and I will supply you with the correct stock tune

[puddlestomper]

I found one at tune depot. Thanks though.

[sac811]

I'm having a similar issue, my ac isn't working, after I did a full flash from my previous tune file with it OS to the current ECU and the AC isn't working.

Does that mean I need to plug in all my information from my current tune, into the tune that I pulled from the new ECU before I did a full flash for it to work?

[puddlestomper]

When I changed computers the new ecm had a different OS. I had to go to tune depot and find the right OS. I just flashed those stock tunes (2tries) until my a/c worked. Then did a cal flash

[sac811]

When I changed computers the new ecm had a different OS. I had to go to tune depot and find the right OS. I just flashed those stock tunes (2tries) until my a/c worked. Then did a cal flash

So basically you flashed in a stock tune twice, then started your truck to make sure the ac worked. Then when you did a cal flash, was it a cal flash with a different OS, or did you have to copy over your tables from your previous computer's file to be able to cal flash it with the new comp's OS?

[puddlestomper]

There were 2 or 3 available operating systems for my 2002 chevrolet. I had to try each 1 to see if that 1 ran my air conditioner. When I found the 1 that would run the air conditioner, I opened is the tune that had the parameters I wanted to run, I did a calibration only flash.

[sac811]

There were 2 or 3 available operating systems for my 2002 chevrolet. I had to try each 1 to see if that 1 ran my air conditioner. When I found the 1 that would run the air conditioner, I opened is the tune that had the parameters I wanted to run, I did a calibration only flash.

Ok, so you copied your tuned tables over to the correct OS you found that ran your a/c and did a cal flash.

Gotcha, the OS I did a full flash with ran my AC previously but maybe I need to try the original ECU OS and see if that runs the AC now...I never did relink VATS with the new ECU, but it runs after the full flash so don't know if that has anything to do with it.

[puddlestomper]

I have v1. I don't know if the two displays differently, but there was a full PCM flash or a calibration only flash option. If you have a tune from the original ECM, you should just be able to flash that operating system into your new PCM. Then put the calibrations in that you want with a calibration Flash. I hope this is clear I am new to EF I live but that is how I fixed mine. Sorry for the grammatical errors but my phone does what it wsnts ob voice to text.

[puddlestomper]

My operating system ended with 4441. That is the only 1 that would run my air conditioner. Any other number that was supposed to be for a 2002 chevrolet my air conditioner did not work.

[GMC-2002-Dmax]

if you guys want to PM me your VIN# I can get the correct factory OS from GM TIS and email you the correct files.

You will have to FULL FLASH THEM in for them to replace what you have now, a CAL FLASH will not work.

[sac811]

I have v1. I don't know if the two displays differently, but there was a full PCM flash or a calibration only flash option. If you have a tune from the original ECM, you should just be able to flash that operating system into your new PCM. Then put the calibrations in that you want with a calibration Flash. I hope this is clear I am new to EF I live but that is how I fixed mine. Sorry for the grammatical errors but my phone does what it wsnts ob voice to text.

No problem, and thank for the help.

I'll see what I can do with the info.

[EagleMark]

I'm not sure about the diesel programming but have had similar issues with gas PCM swaps and OS changes. It is in which way the OS was set in parameters
G1001 to G1009 with an emphasis on G1006.

HTH!

[sac811]

I'm not sure about the diesel programming but have had similar issues with gas PCM swaps and OS changes. It is in which way the OS was set in parameters
G1001 to G1009 with an emphasis on G1006.

HTH!

Sorry, this is actually for a 1999 GMC Sierra 1500 rcsb with a 6.0 that originally had a 5.3

This just came up in search, and didn't realize it was in diesel section until part way into thread conversation

;-)

Also when I type in G1001 or G1006 in tune tool it isn't found, that must be for different ECU or OS than mine

[puddlestomper]

You're on your own there then. I have no idea about gas engines.

[EagleMark]

Sorry, this is actually for a 1999 GMC Sierra 1500 rcsb with a 6.0 that originally had a 5.3

This just came up in search, and didn't realize it was in diesel section until part way into thread conversation

;-)

Also when I type in G1001 or G1006 in tune tool it isn't found, that must be for different ECU or OS than mineLook in System folder for an AC folder and compare the new OS to old OS...