STEP 1. Check if the EGR valve sounds during initialization.
STEP 2. Using scan tool MB991958, read the diagnostic trouble code (DTC)
caution | To prevent damage to scan tool MB991958, always turn the ignition switch is 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) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Is any DTC set?
Refer to, Diagnostic Trouble Code Chart . Go to Step 3.
STEP 3. Using scan tool MB991958, check actuator test.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the actuator test. Refer to Actuator Test Reference Table .- Item 1: Injectors
- Item 10: Evaporative Emission Purge Solenoid
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Are they operating properly?
Go to Step 4. Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 4. Using scan tool MB991958, check data list.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the data list. Refer to Data List Reference Table .- Item 5: Intake Air Temperature Sensor
- Item 6: Engine Coolant Temperature Sensor
- Item 10: Mass Airflow Sensor
- Item 36: Intake V.V.T. Phase Angle
- Item 39: Exhaust V.V.T. Phase Angle
- Item 76: A/C Switch
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Are they operating properly?
Go to Step 5. Repair or replace it. Then confirm that the malfunction symptom is eliminated.
STEP 5. Check the fuel pressure.
STEP 6. Check the ignition timing.
STEP 7. Measure the output voltage at ECM connector B-26 by using power plant ECU check harness special tool MB992110.
(1) Disconnect all ECM connectors. Connect the power plant ECU check harness special tool MB992110 between the separated connectors.
(2) Start the engine and run at idle.note | Vehicles for Canada, the headlight, taillight, etc. remain lit even when the lighting switch is in "OFF" position but this is no problem for checks. |
(3) Measure the voltage between terminal No. 60 and ground.- Engine: warming up, idling
- Radiator fan: stopped
- Headlight: OFF to ON
- Stop light: OFF to ON
- Rear defogger switch: OFF to ON
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Did the measured voltage increase?
Go to Step 8. Replace the generator. Then confirm that the malfunction symptom is eliminated.
STEP 8. Check the spark plugs.
STEP 9. Check the ignition coil.
STEP 10. Check the compression pressure.
STEP 11. Check the positive crankcase ventilation system.
STEP 12. Check the evaporative emission control system.