PCM will not do the relearn procedure. 1999ls1
Thread Starter
Teching In
Joined: Aug 2019
Posts: 3
Likes: 0
PCM will not do the relearn procedure. 1999ls1 Need help. 1999 LS1 received new PCM. Hooked it up and and plugged in battery. Tried the relearn procedure but it never got pass step two. TURNED key to start position for three seconds then run position. Security light stayed on. no flashing. Then it went out after a few seconds . It's supposed to stay on or flash for ten minutes. After two day's iam lost. The car turns over and has fuel pressure but no fire to coil packs. Any info would be appreciated.
TECH Fanatic
Joined: Dec 2017
Posts: 1,468
Likes: 265
From: Bossier City, Louisiana
Where did you get your PCM? Was it flashed with a new operating system that is compatible with your vehicle? Sounds like the Vehicle Anti Theft System (VATS) is still enabled.
Rick
Rick
You have to do some type of program to the pcm with GM programming or I guess someone with hp tuners. Then vats learn either with GM programming the vats system or the 30 minute learn
