This appears to be a new calibration to improve emissions diagnostics:
"This bulletin provides information about installing new Powertrain Control
Module (PCM) software and calibration on certain 2002-2003 vehicles equipped
with 2.2L 4 cylinder engines. The revised calibration includes several OBD
system improvements that should be installed as soon as practical. Install
the new calibration on all affected vehicles identified in this bulletin,
including vehicles in new dealer inventory and any vehicles that return for
service, for any reason, during the applicable 8 year 80,000 mile (130,000
km) emission warranty coverage period."
Robert Hancock Saskatoon, SK, Canada
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