Inspection Procedure 18

COMMENT
- Defective ignition system, abnormal air/fuel ratio, poor compression pressure, etc. are suspected.

TROUBLESHOOTING HINTS
The most likely causes for this case:
- Malfunction of the ignition system.
- Malfunction of air/fuel ratio control system.
- Malfunction of the fuel supply system.
- Poor compression pressure.
- Clogged exhaust system.

DIAGNOSIS
Required Special Tool:
MB991502: Scan Tool (MUT-II)

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.




STEP 1. Using scan tool MB991502, read the diagnostic trouble code (DTC).
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to ON" position.
3. Read the DTC.

If DTC is not output, go to Step 2.

If DTC is output, refer to Diagnostic Trouble Code Chart.




STEP 2. Using scan tool MB991502, check actuator test items 01, 02, 03, 04, 05, 06: Injector.
1. Check following items in the actuator test.
Refer to Actuator Test Reference Table.
a. Item 01, 02, 03, 04, 05, 06: Injector.

If the test items do not indicate a defect, go to Step 3.

If the test items indicate a defect, refer to DTC P0201, P0202, P0203, P0204, P0205, P0206 - Injector Circuit Malfunction.

STEP 3. Check the ignition timing.
Refer to On-vehicle Service - Ignition Timing Check.

If within specifications, go to Step 4.
If not within specifications, check that the crankshaft position sensor and timing belt cover are in the correct position. Then confirm that the malfunction symptom is eliminated.

CAUTION: To prevent damage to scan tool MB991502, always turn the ignition switch to "LOCK" (OFF) position before connecting or disconnecting scan tool MB991502.




STEP 4. Using scan tool MB991502, check data list and actuator test.
1. Connect scan tool MB991502 to the data link connector.
2. Turn the ignition switch to "ON" position.
3. Check the following items in the data list.
Refer to Data List Reference Table.
a. Item 13: Intake Air Temperature Sensor.
b. Item 25: Barometric Pressure Sensor.
c. Item 21: Engine Coolant Temperature Sensor.
d. Item 14: Throttle Position Sensor.
e. Item 59: Heated Oxygen Sensor (rear)
Right Bank Heated Oxygen Sensor (rear)
f. Item 11: Heated Oxygen Sensor (front)
Right Bank Heated Oxygen Sensor (front) California>
g. Item 69: Left Bank Heated Oxygen Sensor (rear) California>
h. Item 39: Left Bank Heated Oxygen Sensor (front) California>

4. Check the following items in the actuator test.
Refer to Actuator Test Reference Table.
a. Item 10: EGR Solenoid.

If the checks above meet the specifications, go to Step 8.

If the checks above do not meet the specifications, repair or replace. Then confirm that the malfunction symptom is eliminated.

STEP 5. Using scan tool MB991502, check data list.
1. Check the following items of data list. Refer to Data List Reference Table.
a. Item 11: Heated Oxygen Sensor (front) Right Bank Heated Oxygen Sensor (front)
b. Item 39: Left Bank Heated Oxygen Sensor (front)

- Voltage should fluctuate between 0 - 0.4 volts and 0.6 - 1.0 volts while idling after the engine has been warmed.

If the voltage does not fluctuate, go to Step 6.

If the voltage fluctuates, go to Step 8.

STEP 6. Check the fuel pressure.
Refer to Fuel Pressure Test.

If correct, go to Step 7.
If incorrect, repair or replace. Then confirm that the malfunction symptom is eliminated.

STEP 7. Check the following items.
1. Check the following items, and repair or replace the defective items.
a. Vacuum leak.
- Broken intake manifold gasket.
- Broken air intake hose.
- Broken vacuum hose.
- Positive crankcase ventilation valve does not operate.

b. Injector clogged.

Then confirm that the malfunction symptom is eliminated.

STEP 8. Check the fuel pressure.
Refer to Fuel Pressure Test.

If correct, go to Step 9.
If incorrect, repair or replace. Then confirm that the malfunction symptom is eliminated.

STEP 9. Check the following items.
1. Check the following items, and repair or replace the defective items.
a. Check the ignition coil, spark plugs, spark plug cables.
b. Check compression pressure.
c. Check the fuel filter or fuel line for clogging.
d. Broken air intake hose.
e. Clogged air cleaner.
f. Clogged exhaust system.

Then confirm that the malfunction symptom is eliminated.