Computer issue please advise

[nic25276]

Ok so i have a 99 chevy silverado 5.3 vin T engine blew up put in donor engine it is a 2002 model 4.8 vin V engine runs idles rough shakes off of idle. and throwing codes for p0300 p0356 p0358 p0303 p0304 p0306 p0308 which leads me to believe that is a PCM issue. The PCM that is in the truck is for the 99 model. I have tried to install the PCM from 2002 model the engine starts runs for a few seconds and dies. So is security tripped? and i need to do a relearn? and if so which relearn procedure do i follow as there are tons online? or do i need a PCM reprogrammed? if so which one? OR AM I JUST BLANKED UP

[SpartanAutoworx]

The pcm from the other truck will work if the config is the same. The issue you will run into will be with the wrong vin being in the pcm when it comes time for inspection.

 

You really should have it re flashed to be correct for the truck.

 

You will need to do the security relearn procedure which requires 30mins. 3x 10min key cycles.

 

Make sure you put a good clean power source on when doing the relearn.

 

youtube spartan autoworx on youtube I made a video about doing the relearn. That should get you back up and running.

[nic25276]

I never thought of that till after putting the engine in. Like I said it has the pcm in it for a 99 5.3 and it's running like crap missing shaking etc. And the pcm for the 2002 4.8 it starts up and dies

[nic25276]

Ok I done the security relearn truck runs better but not like it should code p0300 comes up. But I don't understand why. I just changed a motor I went from a 5.3 to a 4.8 my pcm in the truck should have compensated. The sensors r the same for both motors I has to be something simple I'm missing. Why did changing motors cause this issue