Circuit Description

The Evaporative Emission (EVAP) system is used to store fuel vapors to reduce amount of unburned fuel from escaping into atmosphere. EVAP purge solenoid is used to control flow of fuel vapors from EVAP canister to intake manifold. EVAP purge solenoid is commanded on whenever EVAP system is in purge mode. Fuel vapors can be purged at anytime PCM is in closed-loop and vehicle is not in decel mode. EVAP purge solenoid circuit is monitored for low and high voltage faults. DTC will set when EVAP purge solenoid is commanded on and feedback voltage at PCM is high.

DTC will set if EVAP purge solenoid voltage is greater than 1.25 volts when EVAP purge solenoid is commanded on. Diagnostic runs continuously with engine running and EVAP purge solenoid commanded on.