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Home >> Mitsubishi >> 2006 >> Lancer Evolution L4-2.0L DOHC Turbo >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0446

P0446

DTC P0446: Evaporative Emission Control System Vent Control Circuit

Evaporative Emission Ventilation Solenoid Circuit Part 1:




Evaporative Emission Ventilation Solenoid Circuit Part 2:






CIRCUIT OPERATION
- The evaporative emission ventilation solenoid power is supplied from the MFI relay (terminal No.4).
- The ECM controls the evaporative emission ventilation solenoid ground by turning the power transistor in the ECM ON and OFF.

TECHNICAL DESCRIPTION
- To judge if there is open circuit in the evaporative emission ventilation solenoid drive circuit, ECM measures the surge voltage of the evaporative emission ventilation solenoid coil.
- The ECM drives the evaporative emission ventilation solenoid. After the solenoid is turned off, the ECM will check if the solenoid coil produces a surge voltage of 2 V or more.

DESCRIPTIONS OF MONITOR METHODS
- Off-surge does not occur after solenoid is operated on to off.

MONITOR EXECUTION
- Continuous

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:




Logic Flow Chart

Check Conditions
- Engine is being cranked.
- Battery positive voltage is at between 10 and 16.5 volts.

Judgment Criteria
- The evaporative emission ventilation solenoid coil surge voltage (battery positive voltage +2 volts) is not detected for 0.2 second.
- The ECM 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 the evaporative emission purge solenoid is 0 percent.
- ON duty cycle of the EGR vacuum regulator solenoid valve is 0 percent.
- Evaporative emission ventilation solenoid is ON.
- More than 1 second has elapsed after the above mentioned conditions have been met.

Judgment Criterion
- The evaporative emission ventilation solenoid coil surge voltage (battery positive voltage +2 volts) is not detected for 1 second. When the evaporative emission ventilation solenoid is turned OFF.

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 23. OBD-II Drive Cycle Pattern Lists

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
- Evaporative emission ventilation solenoid failed.
- Open or shorted evaporative emission ventilation solenoid circuit, harness damage, or connector damage.
- ECM failed.

DIAGNOSIS

Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991911: Main Harness B

STEP 1. Using scan tool MB991958, check actuator test item 29: Evaporative Emission Ventilation Solenoid.

CAUTION: To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.




1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Set scan tool MB991958 to the actuator test mode for item 29, Evaporative Emission Ventilation Solenoid.
- An operation sound should be heard and vibration should be felt when the evaporative emission ventilation solenoid is operated.

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the solenoid operating properly?

YES: It can be assumed that this malfunction is intermittent.

NO: Go to Step 2.




STEP 2. Check harness connector F-13 at the evaporative emission ventilation solenoid for damage.

Q: Is the harness connector in good condition?

YES: Go to Step 3.

NO: Repair or replace it. Then go to Step 12.

STEP 3. Check the evaporative emission ventilation solenoid.




1. Disconnect the evaporative emission ventilation solenoid connector F-13.
2. Measure the resistance between evaporative emission ventilation solenoid side connector terminal No.1 and No.2.

Standard value: 17 - 21 Ohms [at 20 degrees C (68 degrees F)]

Q: Is the measured resistance between 17 and 21 Ohms [at 20 degrees C (68 degrees F)]?

YES: Go to Step 4.

NO: Replace it. Then go to Step 12.

STEP 4. Measure the power supply voltage at evaporative emission ventilation solenoid harness side connector F-13.




1. Disconnect connector F-13 and measure at the harness side.
2. Turn the ignition switch to the "ON" position.




3. Measure the voltage between terminal No.2 and ground.
- Voltage should be battery positive voltage.

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is battery positive voltage (approximately 12 volts) present?

YES: Go to Step 6.

NO: Go to Step 5.




STEP 5. Check harness connector B-12X at MFI relay for damage.

Q: Is the harness connector in good condition?

YES: Check connectors C-21, C-105, C-123 and C-127 at intermediate connector for damage, and repair or replace as required. If the intermediate connectors are in good condition, repair the harness wire between MFI relay connector B-12X (terminal No.4) and evaporative emission ventilation solenoid connector F-13 (terminal No.2) because of open circuit or short circuit to ground. Then go to Step 12.

NO: Repair or replace it. Then go to Step 12.

STEP 6. Measure the power supply voltage at ECM connector C-121 by backprobing.




1. Do not disconnect connector C-121.
2. Turn the ignition switch to the "ON" position.




3. Measure the voltage between terminal No.35 and ground by backprobing.
- Voltage should be battery positive voltage.

4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is battery positive voltage (approximately 12 volts) present?

YES: Go to Step 9.

NO: Go to Step 7.




STEP 7. Check harness connector C-121 at ECM for damage.

Q: Is the harness connector in good condition?

YES: Go to Step 8.

NO: Repair or replace it. Then go to Step 12.







STEP 8. Check for open circuit and short circuit to ground between evaporative emission ventilation solenoid connector F-13 (terminal No.1) and ECM connector C-121 (terminal No.35).

NOTE: Check harness after checking intermediate connectors C-122 and C-127. If the intermediate connectors are damaged, repair or replace them. Then go to Step 12.

Q: Is the harness wire in good condition?

YES: Replace the ECM. Then go to Step 12.

NO: Repair it. Then go to Step 12.




STEP 9. Check harness connector C-121 at ECM for damage.

Q: Is the harness connector in good condition?

YES: Go to Step 10.

NO: Repair or replace it. Then go to Step 12.







STEP 10. Check for harness damage between MFI relay connector B-12X (terminal No.4) and evaporative emission ventilation solenoid connector F-13 (terminal No.2).

NOTE: Check harness after checking intermediate connectors C-21, C-105, C-123 and C-127. If any of the intermediate connectors are damaged, repair or replace them. Then go to Step
12.

Q: Is the harness wire in good condition?

YES: Go to Step 11.

NO: Repair it. Then go to Step 12.







STEP 11. Check for harness damage between evaporative emission ventilation solenoid connector F-13 (terminal No.1) and ECM connector C-121 (terminal No.35).

NOTE: Check harness after checking intermediate connectors C-122 and C-127. If any of the intermediate connectors are damaged, repair or replace them. Then go to Step 12.

Q: Is the harness wire in good condition?

YES: Replace the ECM. Then go to Step 12.

NO: Repair it. Then go to Step 12.

STEP 12. 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 23. OBD-II Drive Cycle Pattern Lists
2. Check the diagnostic trouble code (DTC).

Q: Is DTC P0446 set?

YES: Retry the troubleshooting.

NO: The inspection is complete.
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