The evaporative emission (EVAP) system is used to store fuel vapors as to reduce the amount of unburned fuel from escaping into the atmosphere. The EVAP purge solenoid is used to control the flow of fuel vapors from the EVAP canister to the intake manifold. The EVAP purge solenoid is commanded ON (pulse width modulation - PWM) whenever the EVAP system is in purge mode. Fuel vapors can be purged at anytime the powertrain control module (PCM) is in Closed Loop and the vehicle is not in a decel. The PCM controls the EVAP purge solenoid by controlling an internal driver that pulls the solenoid circuit to ground. The EVAP purge solenoid circuit is monitored for low and high voltage faults. DTC P0445 sets when the EVAP purge solenoid is commanded ON and the feedback voltage at the PCM is high.
DTC Parameters
DTC P0445 will set if EVAP purge solenoid feedback voltage is greater than 1.25 volts with EVAP purge solenoid commanded ON when:
| • | The condition exists for longer than 0.5 seconds. |
| • | The engine is running. |
DTC P0445 diagnostic runs continuously with engine running and EVAP purge solenoid commanded ON.
DTC P0445 is a type D DTC.
Diagnostic Aids
To locate an intermittent problem, use a scan tool to command EVAP PURGE SOLENOID ON, PWM 100 percent duty cycle, while monitoring the EVAP PURGE - HIGH VOLT test. When a fault, short to voltage or shorted solenoid exists, the scan tool will display TEST FAIL.
The test will fail only when the device is being commanded ON and the voltage at the PCM is high. The test updates every 100 ms whenever the ignition is turned ON and the device is being commanded ON via the scan tool or PCM.
The EVAP purge solenoid resistance is 19-31 ohms.
