Quote Originally Posted by joecar View Post

PCM determines AFR from:
- CL: closed loop feedback trimming to stoichiometric AFR (B3601),
- OL: the richer of: B3605, B3647 (COS), and B3618 (if PE has enabled from B3608-B3616).

Joe, this is still a little confusing to me. I agree in OL it selects the richer of B3605 and B3618. But in CL, OL utilizes B3618..regardless of B3605. Remember my little experiment?

The various protection mode AFR's are reflected in the commanded AFR.
The PCM selects the richest AFR from the AFR tables active at that moment.

PCM uses OL when:
- cold,
- at WOT,
- in PE,
- during throttle/airflow transients,
- CL is disabled.
- during EVAP (OL-Drive) Depending on OS.

VE/MAF determine airmass.
OL/CL determine commanded AFR.

SD/MAF are orthogonal to OL/CL (there exists 4 combinations of these).

PCM also uses airmass to determine ignition timing and transmission pressure.
Joe, again great work. I don't want to 'muddy' up your work with too many asterisks or exceptions, but the PE vs OLFA still seems to be the case. Perhaps the EVAP is just in the 2002..since no one else seems to comment on it..