P0443
The content of this article reflects the changes identified in TSB-08-13-002.DTC P0443: Evaporative Emission Control System Purge Control Valve Circuit
Evaporative Emission Purge Solenoid Circuit Part 1:
Evaporative Emission Purge Solenoid Circuit Part 2:
CIRCUIT OPERATION
The evaporative emission purge solenoid power is supplied from the MFI relay (terminal No. 2).
The ECM controls ground evaporative emission purge solenoid by turning the power transistor in the ECM "ON" and "OFF".
TECHNICAL DESCRIPTION
To judge if there is open circuit in the evaporative emission purge solenoid drive circuit, the ECM measures the surge voltage of the evaporative emission purge solenoid coil.
DESCRIPTIONS OF MONITOR METHODS
Off-surge does not occur after solenoid is operated from 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 between 10 and 16.5 volts.
Judgement 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 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.
Judgement Criterion
The evaporative emission purge solenoid coil surge voltage (battery positive voltage + 2 volts) is not detected for 1 second after the evaporative emission purge solenoid is turned off.
DTC SET CONDITIONS
Logic Flow Chart:
Logic Flow Chart
Check Conditions
Battery positive voltage is 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.
Judgement Criterion
The evaporative emission purge solenoid coil surge voltage (battery positive voltage + 2 volts) is not detected for 1 second after the evaporative emission purge solenoid is turned off.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 24. OBD-II Drive Cycle
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
Evaporative emission purge solenoid failed.
Harness damage
Connector damage
ECM failed.
DIAGNOSIS
Required Special Tools:
- MB991958: Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: V.C.I.
- MB991827: USB Cable
- MB991910: Main Harness A
STEP 1. Using scan tool MB991958, check actuator test item 10: Evaporative Emission Purge 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 10, Evaporative emission purge solenoid.
- An operation sound should be heard and vibration should be felt when the evaporative emission purge 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 A-33X at the MFI relay and harness connector B-07 at the evaporative emission purge solenoid and harness connector B-10 at the ECM for damage.
Q: Is the harness connector in good condition?
YES: Go to Step 3.
NO: Repair it. Then go to Step 7.
STEP 3. Check the evaporative emission purge solenoid.
1. Disconnect the evaporative emission purge solenoid connector B-05.
2. Measure the resistance between evaporative emission purge solenoid side connector terminal No. 1 and No. 2.
Standard value: 22 - 26 ohms [at 20 °C (68 °F)]
Q: Is the measured resistance between 22 and 26 ohms [at 20 °C (68 °F)]?
YES: Go to Step 4.
NO: Replace the evaporative emission purge solenoid. Then go to Step 7.
STEP 4. Measure the power supply voltage at the evaporative emission purge solenoid connector B-07.
1. Disconnect the evaporative emission purge solenoid connector B-07 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 the measured voltage between 4.9 and 5.1 volts?
YES: Go to Step 5.
NO: Repair it. Then go to Step 7.
STEP 5. Check for open circuit and short circuit to ground and harness damage between the evaporative emission purge solenoid connector B-07 and the ECM connector B-10.
1. Disconnect the evaporative emission purge solenoid connector B-07 and the ECM connector B-10.
2. Measure the evaporative emission purge solenoid connector B-07 (terminal No. 1) and the ECM connector B-10 (terminal No. 37).
Should be less than 2 ohms.
3. Check for the evaporative emission purge solenoid connector B-07 (terminal No. 1) and ground.
Not continuity.
Q: Is the harness wire in good condition?
YES: Go to Step 6.
NO: Repair it. Then go to Step 7.
STEP 6. Check the trouble symptoms.
1. Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 24. OBD-II Drive Cycle
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0443 set?
YES: Replace the ECM. When the ECM is replaced, register the ID code. Refer to ID Code Registration Judgment Table
NO: It can be assumed that this malfunction is intermittent.
STEP 7. 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 24. OBD-II Drive Cycle
2. Check the diagnostic trouble code (DTC).
Q: Is DTC P0443 set?
YES: Retry the troubleshooting.
NO: The inspection is complete.