DTC P0443: Evaporative Emission Control System Purge Control Valve Circuit

CIRCUIT OPERATION
• Power to the evaporative emission purge solenoid power is supplied from the MFI relay (terminal No. 1).
• The PCM controls ground evaporative emission purge solenoid by turning the power transistor in the PCM "ON" and "OFF".
TECHNICAL DESCRIPTION
• To judge if there is open circuit in the evaporative emission purge solenoid drive circuit, PCM measures the surge voltage of the evaporative emission ventilation solenoid coil.
DESCRIPTIONS OF MONITOR METHODS
Off-surge does not occur after solenoid is operated from on to off.
MONITOR EXECUTION
Once per driving cycle
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
• Not applicable

Sensor (The sensor below is determined to be normal)
• Not applicable
DTC SET CONDITIONS Logic Flow Chart


Check Conditions
Battery positive voltage is at between 10 and 16.5 volts.

Judgment Criteria
The evaporative emission purge solenoid coil surge voltage (battery positive voltage + 2 volts) is not detected for 0.2 second.
The PCM monitors for this condition once during the drive cycle.

Check Conditions
Battery positive voltage is at between 10 and 16.5 volts.
ON duty cycle of the evaporative emission purge solenoid is between 10 and 90 percent.
Evaporative emission ventilation solenoid is OFF.
More than 1 second has elapsed after the above mentioned conditions have been met.

Judgment Criteria
The evaporative emission purge solenoid coil surge voltage (battery positive voltage + 2 volts) is not detected for 1 second. When the evaporative emission purge solenoid is turned OFF.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Procedure 6 - Other Monitor .
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:
• Evaporative emission purge solenoid failed.
• Open or shorted evaporative emission purge solenoid circuit, harness damage or connector damage.
• PCM failed.