I have a 1999 GMC sierra and have seen a lot of people going to '02 pcm's what's the benefit??????

 

Im going with an 02 pcm for my 99 when I order up my nelson tune here in the next few days. I think the reason is because the 99's put out a false spark knock signal which retards the timing...

 

yep I also upgraded to a 02 to help fight faults KR.

 

Also 2000 and earlier (I believe this applies to the trucks as well... I just peaked at a 99 silverado tune and it's true for that) have a secondary VE table... when the PCM enters the SD failover mode, it reverts to the Secondary VE table...

The Secondary table is 1/2 the resolution of the Primary...

The 2001+ use only the Primary VE Table (no secondary) so for SD tuning you get more resolution and can make finer tuning changes

 

thanks for your feed back guys...... going to be calling nelson here soon to get my '02 pcm underway.

 

so if it all got fixed in 01 why does everyone want the 02 and up ?

 

Its either 01 or 02. The term 02 pcm just stuck. Guys with 01's say 02 pcm in there sigs.

 

GM Fixes code over time... so at least for F-Body's the 02 Operating system was the best available... so given a choice between 01/02 most go with 02 ... it's like the operating system on your computer... few things (well ok.. we're talking about Msoft so many ) have been fixed each year... or code updated...

But the differences aren't very extreme (from what I know...) ... the main reason is the higher resolution single VE table for SD tuning

 

Since you have a 99, you're gonna want to get some 00 or newer injectors also. The 99's have 21 lb injectors, and 00 and up (or at least 00 to 02, still not sure about 03 and up), have 24.7 lb injectors. You can usually find them in the classifieds for less than $100.

 

actually the 99's were 19#, they updated in 00 and again in 01.

Chris