PCM interchangeability?

Perry · May 29, 2004

I have a 2002 Silverado w/5.3L that needs a new PCM. What years and/or models PCM will work with my truck? Will any V8 PCM from '00-'04 work? or does it have to be from '02? Does it have to be from a 5.3L? Would a '02 Avalanche w/5.3L work? Any help on the subject would be apprectiated.

Thanks,

Perry

PewterC3 · May 29, 2004

There is a service number on the PCM you just need to match. Most 01-02 V8's should be the same though I think.

99Silver6.0 · May 29, 2004

I have a 99 Rado and I am currently running a 2002 PCM. I had a problem with bad KR on my 99 PCM. But man oh man how much better my 99 runs with the 2002 PCM!!!! So you can switch 'em and it will work. You just have to perform the security relearn before the truck will start. Make sure you do NOT use a 99 PCM and make sure you get it for a 5.3.

budhayes3 · May 29, 2004

Hey 99Silver5.3, where'd you get your 02 PCM and how much did it run ya? I too have a 99 5.3, but have yet to check my KR. I have a basic AutoXray (I think I paid like $150 on sale for it or something) but it doesn't show knock or KR. It will pull and clear codes and can display some live data, one reading at a time, like coolant temp, O2 voltage, LT and ST fuel trim, MAP, etc. I do have access to a Toyota/Lexus scan tool at work, which will display CARB OBDII data, but have not had the time to check it out.

I think I read once about 10K-Ohm resistors wired in to the knock harness. After I check out my data, I was thinking of cruisin to the junk yard if necessary and cutting out some harness connectors to make the resistor harness plug and play, but if it's cheap enough, I'll just swap PCM's.

Also gonna be adding a very mild cam soon...

budhayes3 · May 29, 2004

Oh Yea, Nice Truck!

Perry · May 29, 2004

Thanks for the replys everyone.

99silver5.3 - How do I perform the security relearn? Is it something I can do myself or do I need a dealership/special tool to perform it?

Thanks again,

Perry

99Silver6.0 · May 29, 2004

Bud,

I got the PCM at a salvage yard for 60 bucks. The knock retard bacame a big problem after I putmy cam in. I had to do something and trying a new PCM seemes the easiest rout for now. And low and behold it worked! My truck runs great. But the bad thing is I cannot use my LS1Edit on this 02 PCM which sucks!! Do some logging and see if you are getting any KR and how much. I was getting dam near 9* all the dam time. Try some 100 octane or mix up some Xylene and 91. There are recipes and formulas on the net on how to make 100 or 110 octane with Xylene and 91 octane gasoline. Thats what I did. If the KR does not disappear with higher octane gasoline it is false.

Perry,

Thanks for the compliment. The security re-learn is actually very simple. It just takes some time. Here is the instructions for the re-learn:

This Procedure will take approximately 20-30 minutes. After your PCM is installed, please perform the following. You may want to be outside your vehicle so shut the door, roll down the window.

PROCEDURE:

Insert key, attempt to start the vehicle and leave the key in the ON position.

In some vehicles, the Battery and Security light will blink for several seconds, and then shut off. Then the Security light will then remain ON. Leave the ignition ON until the Security light goes OFF. This will take more than 5 mins.

When the Security light goes OFF, turn the ignition to the OFF position.

Leave ignition OFF for 20 Seconds.

Attempt to start the vehicle again and leave the key in the ON position.

In some vehicles, the Battery and Security light will blink for several seconds, and then shut off. Then the Security light will then remain ON. Leave the ignition ON until the Security light goes OFF. This will take more than 5 mins.

Turn the ignition to the OFF position for 20 Seconds.

Attempt to start the vehicle again and leave the key in the ON position.

In some vehicles, the Battery and Security light will blink for several seconds, and then shut off. Then the Security light will then remain ON. Leave the ignition ON until the Security light goes OFF. This will take more than 5 mins.

Once this entire procedure has been completed (three times) your vehicle will start on the fourth attempt.

Note: Some vehicles perform the relearn in a different sequence. You may notice your security light, battery light and abs light will alternate. Once the security light is left out of the sequence that is considered one step. Repeat the procedure two more times and on the fourth time your vehicle will start.

FAQs:

-The procedure was just completed now my car is making a clicking noise when I attempt to start it.

Your battery may have become too weak to crank the engine over.

-I performed the procedure and my vehicle still doesn’t start

Please repeat the procedure again.

Instructions courtesy of Nelson Performance.

Perry · May 30, 2004

99Silver5.3 - Thanks so much for the instructions and help. I saved this post to a word file so I won't forget.

Thanks again,

Perry

99Silver6.0 · May 30, 2004

99Silver5.3 - Thanks so much for the instructions and help. I saved this post to a word file so I won't forget.

Thanks again,

Perry

No problem!

budhayes3 · May 30, 2004

Thanks a ton 99Silver5.3! That's some geat info!

99GMCZ71 · June 1, 2004

I thought the VIN number was in the PCM. Without the correct VIN, the PCM will not work. If you can just swap PCM's, why would Wester's or anybody else need your VIN, unless it keeps you from doing the relearn maybe.

99Silver6.0 · June 1, 2004

I thought the VIN number was in the PCM. Without the correct VIN, the PCM will not work. If you can just swap PCM's, why would Wester's or anybody else need your VIN, unless it keeps you from doing the relearn maybe.

Dude, you can swap them. You can use a 6.0 PCM if you want. Just have to do the relearn. The VIN is in the PCM, although the PCM I am currently running doesnt match my truck VIN. This PCM was just a test for me. My 99 PCM is getting updated by my friend with a TechII next weekend.

scooter70 · June 2, 2004

The actual PCM is the same for Corvettes, trucks, and F-bodies. The difference is the program that is on it. You could go out and buy a '99 Camaro Z28 PCM and use it on your truck, you just need a dealer (or someone else with the right hardware) to put the correct program on it for your truck. ('97-'99 LS1 PCMs have a different case, so they might not work. '99-04 are the same.)

I learned this while searching for a PCM for my LS1 powered 1970 Corvette. Check out http://www.speartech.com/compreprog.html. Speartech does programming and harnesses for lots of GM fuel injected vehicles. (John Spears worked for GM and Delphi and developed some of the current injection and ignition systems so he knows what he's doing.)

Butch 02 Denali · June 2, 2004

The service number for the 99-00 PCM is #09354896. The 01-02 PCM is #12200411 and the 03-04 is #12576106 + #12582605. The #411 may be used as a core for the 99-00 but other than that there is NO interchangeability. You cannot use a PCM that is programmed for any other year or engine size without getting dozens of error codes and performance issues. The fuel map between the 6.0 and 5.3 are very different and are not interchangeabe. The PCM from a 6.0 is also programmed for a 4L80 tranny and is not compatable with the 4L60 program. Even if you had a PCM from the same year with the same engine size, and did a security relearn for the VIN, you could have many of the options in the truck not work, like the door locks and more, all controlled by the PCM through 8 other modules in the truck. About the only way to use a PCM from another year is to have it reflashed with the program for your year and engine, and if you want your options to work, it must be flashed to your exact VIN.

Jared, you use the LS1Edit program don't you? That is about the only way to accomplish a PCM swap like you have done.

Butch 02 Sierra Denali

99GMCZ71 · June 2, 2004

The service number for the 99-00 PCM is #09354896. The 01-02 PCM is #12200411 and the 03-04 is #12576106 + #12582605. The #411 may be used as a core for the 99-00 but other than that there is NO interchangeability. You cannot use a PCM that is programmed for any other year or engine size without getting dozens of error codes and performance issues. The fuel map between the 6.0 and 5.3 are very different and are not interchangeabe. The PCM from a 6.0 is also programmed for a 4L80 tranny and is not compatable with the 4L60 program. Even if you had a PCM from the same year with the same engine size, and did a security relearn for the VIN, you could have many of the options in the truck not work, like the door locks and more, all controlled by the PCM through 8 other modules in the truck. About the only way to use a PCM from another year is to have it reflashed with the program for your year and engine, and if you want your options to work, it must be flashed to your exact VIN.
Jared, you use the LS1Edit program don't you? That is about the only way to accomplish a PCM swap like you have done.

Butch 02 Sierra Denali

I had the exact same thought. How could a PCM for a 6.0 work in a 5.3. No way in this world it would run right, if it would even start.