believe it or not the procedure changes between models even if its a vats/passkeyI/II/or III, and even if its the BCM or ICM based units (cheapo cars got the instrument cluster module based systems)
you have oddballs like the achieva's and the other "leftover parts bin" cars towards the end.
i had an 04 regal gs with no passkeyIII
none
95 park aves that do a security learn in only one 10 min cycle...btw the ign switch can turn without the key.
the earlier 1.5 lumi's and monte's often didnt have it enabled, lots of those cars were probably gm test vehicles during the transition? **** thats the only way i can explain working on a 95 model year regal with an OEM SII, built in 4 of 94. owner bought it at an auction in 96.
that one regal probably got me more into this **** than anything else, come to find out i had to tell the scanner it was a 96 before i could get into it...it was NOT a conventional 1.5 car lol
also **** pk3