Operation CHARM: Car repair manuals for everyone.

Emissions Diagnosis For State I/M Programs

This OBD II equipped vehicle is designed to self-diagnose any conditions that could lead to excessive levels of the following emissions:
^ Hydrocarbons (HC)
^ Carbon monoxide (CO)
^ Oxides of nitrogen (NOx)
^ EVAP system losses

Should this vehicle's on-board diagnostic system (ECM) detect a condition that could result in excessive emissions, the ECM turns on the MIL and stores a DTC that is associated with the condition. Always begin the diagnosis with the Powertrain On-board Diagnostic (OBD) System Check when diagnosing a condition reported from a state I/M program. Additional information on the on-board diagnostic system I/M ready status and drive cycle appears later.