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DTC P04DF: Evaporative Emission Control System Purge Control Valve Stuck Open
 
 
 
 
CIRCUIT OPERATION
  • Refer to DTC P0458 - Evaporative Emission Control System Purge Control Valve Circuit Low .
 
 
TECHNICAL DESCRIPTION
  • From the pressure change in the evaporative emission canister when the switching valve is closed without purge introduction, the stuck open failure of the evaporative emission purge solenoid is detected.
 
 
MONITOR EXECUTION
  • Once per driving cycle.
 
 
MONITOR EXECUTION CONDITIONS (Other monitor and Sensor)
Other Monitor (There is no temporary DTC set in memory for the item monitored below)
  • Barometric pressure sensor monitor
  • Barometric pressure sensor/Manifold absolute pressure correlation
  • Evaporative emission purge solenoid monitor
  • Bypass valve monitor
  • Fuel tank solenoid valve monitor
  • Bypass valve/Fuel tank solenoid valve monitor
  • Switching valve monitor
  • Canister pressure sensor monitor
  • Fuel tank pressure sensor monitor
Sensor (The sensor below is determined to be normal)
  • Mass airflow sensor
  • Engine coolant temperature sensor
  • Intake air temperature sensor
  • Barometric pressure sensor
  • Throttle position sensor
  • Manifold absolute pressure sensor
 
 
DTC SET CONDITIONS
Logic Flow Chart
Check Conditions
  • Engine coolant temperature is higher than 20°C (68°F).
  • Intake air temperature is higher than 5°C (41°F) and lower than 55°C (131°F).
  • Mass airflow sensor output is 10 g/sec or more.
  • The ratio between the manifold absolute pressure and the barometric pressure is less than 0.96.
  • The closed loop air-fuel control continues for 20 seconds or more.
  • 12V starter battery positive voltage is 11 volts or higher.
  • Engine is running.
  • Bypass valve is not driving.
  • More than 1 second has elapsed after the above mentioned conditions have been met.
  • While engine is running, following condition is not even met once: intake air temperature is 5°C (41°F) or lower, or 55°C (131°F) or higher.
Judgment Criterion
  • For 2 seconds, the canister pressure subtracted from the barometric pressure is more than 0.72 kPa (0.213 in.Hg) without the evaporative emission purge solenoid driving.
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Prohibit introduction of purges
 
 
OBD-II DRIVE CYCLE PATTERN
  • Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 2 .
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • Evaporative emission purge solenoid stuck open.
  • Shorted evaporative emission purge solenoid circuit or connector damage.
  • ECM failed.

 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), read the diagnostic trouble code (DTC).
cautionTo prevent damage to scan tool (M.U.T.-IIISE), always turn off the power supply mode of the electric motor switch before connecting or disconnecting scan tool (M.U.T.-IIISE).
(1) Connect scan tool (M.U.T.-IIISE). Refer to HOW TO CONNECT THE SCAN TOOL (M.U.T.-IIISE) .
(2) Turn on the power supply mode of the electric motor switch.
(3) Read the DTC.
(4) Turn off the power supply mode of the electric motor switch.
Is DTC P0458 or P0459 set?
Refer to DTC P0458 - Evaporative Emission Control System Purge Control Valve Circuit Low Input , P0459 - Evaporative Emission Control System Purge Control Valve Circuit High Input .
Go to Step 2.
 
STEP 2. Check the evaporative emission purge solenoid for leaks.
Refer to GROUP 17, Emission Control - Evaporative Emission Control System - Evaporative Emission Purge Solenoid Check .
Does the evaporative emission purge solenoid hold pressure?
Go to Step 3.
Replace the evaporative emission purge solenoid. Then go to Step 4.
 
STEP 3. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 2 .
(2) Check the diagnostic trouble code (DTC).
Is DTC P04DF set?
Replace the ECM (Refer to Removal and Installation ). Then go to Step 4.
The inspection is complete.
 
STEP 4. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 2 .
(2) Read the diagnostic trouble code.
Is DTC P04DF set?
Retry the troubleshooting.
The inspection is complete.