FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
Courtesy of Operation CHARM: Car repair manuals for everyone.
Home >> Mitsubishi >> 2011 >> Lancer Sportback L4-2.0L (4B11) >> Repair and Diagnosis >> A L L Diagnostic Trouble Codes ( DTC ) >> Testing and Inspection >> P Code Charts >> P0489

P0489




DTC P0489: EGR Valve (stepper motor) Circuit Malfunction (ground short)






















CIRCUIT OPERATION

- The EGR valve power is supplied from the MFI relay (terminal No. 2).
- The ECM (terminals No. 31, No. 32, No. 47, No. 48) drives the stepper motor by sequentially turning "ON" the power transistors in the ECM and providing ground to the EGR valve (terminal No. 1, No. 3, No. 4, No. 6).

TECHNICAL DESCRIPTION

The ECM checks whether a short circuit to the ground or an open circuit exists or not by measuring the EGR valve (stepper motor) drive circuit voltage when the current is not flowing through the coil of the EGR valve (stepper motor).

DESCRIPTIONS OF MONITOR METHODS

When the EGR valve (stepper motor) drive circuit voltage is under the specified range, it is judged that a malfunction exists.

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)

- Exhaust gas recirculation (EGR) stepper motor monitor
Sensor (The sensor below is determined to be normal)

- Mass airflow sensor
- Engine coolant temperature sensor
- Intake air temperature sensor
- Barometric pressure sensor
- Accelerator pedal position sensor
- Manifold absolute pressure sensor

DTC SET CONDITIONS

Logic Flow Chart






Check Conditions

- Ignition switch is "ON" position.
- Battery positive voltage is between 10 and 16.5 volts.
Judgement Criterion

- When EGR valve is de-energized, the ECM voltage is less than 1.5 volts for 1.4 seconds.

FAIL-SAFE AND BACKUP FUNCTION

- None

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 3 Monitors, Trips, Drive Cycles and Readiness Codes .

TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)

- EGR valve (stepper motor) failed.
- Open or shorted EGR valve (stepper motor) 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
- MB991910: Main Harness A
- MB991658: Test Harness Set
- MB992110: Power Plant ECU Check Harness

STEP 1. Check harness connector B-114 at EGR valve for damage.

Q. Is the harness connector in good condition?

YES Go to Step 2.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 11.
STEP 2. Check the EGR valve.

(1)Disconnect the EGR valve connector B-114.





(2)Measure the resistance between EGR valve side connector terminal No. 2 and either terminal No. 1 or terminal No. 3.
Standard value: 20 - 24ohms [at 20°C (68°F)]
 (3)Measure the resistance between EGR valve side connector terminal No. 5 and either terminal No. 4 or terminal No. 6
Standard value: 20 - 24ohms [at 20°C (68°F)]
Q. Is the measured resistance between 20 and 24ohms [at 20°C (68°F)]?

YES Go to Step 3.

NO Replace the EGR valve. Then go to Step 11.

STEP 3. Measure the power supply voltage at EGR valve harness side connector B-114.

(1)Disconnect the connector B-114 and measure at the harness side.

(2)Turn the ignition switch to the "ON" position.





(3)Measure the voltage between terminal No. 2, No. 5 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 5.

NO Go to Step 4.

STEP 4. Check harness connector A-30X at MFI relay for damage.

Q. Is the harness connector in good condition?

YES Check harness connector A-10 at intermediate connector for damage, and repair or replace as required. Harness Connector Inspection.
If intermediate connector is in good condition, repair harness wire between MFI relay connector A-30X (terminal No. 2) and EGR valve connector B-114 (terminal No. 2, No. 5) because of open circuit or short circuit to ground. Then go to Step 11.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 11.
STEP 5. Check harness connector B-108 at ECM for damage.

Q. Is the harness connector in good condition?

YES Go to Step 6.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 11.
STEP 6. Measure the power supply voltage at ECM harness side connector B-108.

(1)Disconnect the connector B-108 and measure at the harness side.

(2)Turn the ignition switch to the "ON" position.





(3)Measure the voltage between terminal (No. 31, No. 32, No. 47, No. 48) 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 7.

NO
Repair harness wire between EGR valve connector and ECM connector because of open circuit or short circuit to ground.
1. EGR valve connector B-114 (terminal No. 1) and ECM connector B-108 (terminal No. 31).
2. EGR valve connector B-114 (terminal No. 3) and ECM connector B-108 (terminal No. 32).
3. EGR valve connector B-114 (terminal No. 4) and ECM connector B-108 (terminal No. 47).
4. EGR valve connector B-114 (terminal No. 6) and ECM connector B-108 (terminal No. 48).
Then go to Step 11.

STEP 7. Check harness connector A-30X at MFI relay for damage.

Q. Is the harness connector in good condition?

YES Go to Step 8.
NO Repair or replace it. Harness Connector Inspection.
Then go to Step 11.
STEP 8. Check for harness damage between MFI relay connector A-30X (terminal No. 2) and EGR valve connector B-114 (terminal No. 2, No. 5).

NOTE:
Check harness after checking intermediate connector A-10. If intermediate connector is damaged, repair or replace it. Harness Connector Inspection. Then go to Step 11.

Q. Is the harness wire in good condition?

YES Go to Step 9.
NO Repair it. Then go to Step 11.
STEP 9. Check for harness damage between EGR valve connector and ECM connector.

5. EGR valve connector B-114 (terminal No. 1) and ECM connector B-108 (terminal No. 31).

6. EGR valve connector B-114 (terminal No. 3) and ECM connector B-108 (terminal No. 32).

7. EGR valve connector B-114 (terminal No. 4) and ECM connector B-108 (terminal No. 47).

8. EGR valve connector B-114 (terminal No. 6) and ECM connector B-108 (terminal No. 48).

Q. Are the harness wires in good condition?

YES Go to Step 10.
NO Repair them. Then go to Step 11.
STEP 10. Check the trouble symptoms.

(1)Carry out a test drive with the drive cycle pattern. Refer to Diagnostic Function - OBD-II Drive Cycle - Pattern 3 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P0489 set?

YES Replace the ECM (Refer to, Removal and Installation Removal and Replacement).
Then go to Step 11.
NO It can be assumed that this malfunction is intermittent. How to Cope With Intermittent Malfunctions.
STEP 11. 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 3 Monitors, Trips, Drive Cycles and Readiness Codes.

(2)Check the diagnostic trouble code (DTC).

Q. Is DTC P0489 set?

YES Retry the troubleshooting.
NO The inspection is complete.
pro multis Credits:Operation CHARM About Operation CHARM