P0443
DTC P0443: Evaporative Emission Control System Purge Control Valve Circuit
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
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 ECM 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.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 22 Monitors, Trips, Drive Cycles and Readiness Codes.
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. How to Cope With Intermittent Malfunctions.
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. Harness Connector Inspection.
Then go to Step 7.
STEP 3. Check the evaporative emission purge solenoid.
(1)Disconnect the evaporative emission purge solenoid connector B-07.
(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 22 Monitors, Trips, Drive Cycles and Readiness Codes.
(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 registration procedure manual - ID codes registration judgement table [Vehicles with KOS] or ID registration procedure manual - ID codes registration judgement table [Vehicles with WCM]. Then go to Step 7.
NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
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 22 Monitors, Trips, Drive Cycles and Readiness Codes.
(2)Check the diagnostic trouble code (DTC).
Q. Is DTC P0443 set?
YES Retry the troubleshooting.
NO The inspection is complete.