DTC P1451: - Evaporative Emission System Vent Control Circuit

DTC P1451: - EVAPORATIVE EMISSION SYSTEM VENT CONTROL CIRCUIT

Description:	Monitors the canister vent (CV) solenoid circuit for an electrical failure. The test fails when the signal moves outside the minimum or maximum allowable calibrated parameters for a specified canister vent duty cycle by powertrain control module (PCM) command.
Possible Causes:	VPWR circuit open CV solenoid circuit short to PWR GND or CHASSIS GND Damaged CV solenoid CV solenoid circuit open CV solenoid circuit short to VPWR
Diagnostic Aids:	To verify normal functioning, monitor the evaporative emission (EVAP) CV solenoid signal PID EVAPCV and the signal voltage on the PCM control side. With the valve open, the EVAPCV PID indicates 0% duty cycle and a voltage approximately equal to battery voltage. When the valve is commanded fully closed, the EVAPCV PID indicates 100% duty cycle, and a minimum voltage drop of 4 volts is normal. Output test mode (OTM) may be used to switch the output on and off to verify function.
Application	Key On Engine Off	Key On Engine Running	Continuous Memory
All	GO to Pinpoint Test HX .