is there a how to on installing a 01 pcm in a 99 silverado? i know you can swap them out. but, i thought there was something to do with alternator wireing.

 

Not sure which programmer your using.
If EFI, they have an excellent resources try the forum or check the tutorials.

 

The 99-00 alternators have two wires....a turn-on wire, and a battery wire. There is no monitoring from the PCM. The 01 alternators have a third wire that senses the duty cycle or output of the alternator. If you put that 01 PCM into the 99 truck all you have to do is disable the code for Generator F Terminal I believe (it may also be L, but I'm pretty sure it's F).

 

oh ok gotcha. he wants me to tune it anyway. and i have HPT.

 

i here on hpt that swaping pcm's or OS's that it can cause other problems such as fuel ind not to read right.

 

I hadn't heard that before...can't be of any help on that, sorry