Inspection Procedure 13: Black Smoke, State of Exhaust Gas Purification Deteriorated

PROBABLE CAUSES

Improper fuel used
Injector leaking or clogged
Failed injector
Fuel injection learning failure
Failed fuel pressure limiter valve
Failed fuel pressure sensor
Failed supply pump (suction control valve)
Failed supply pump correction learning
Failed EGR system operation
Failed glow system
Failed engine-ECU
Compression pressure low
Failed turbocharger
Improper engine oil volume or viscosity

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III diagnosis code.

Q. Is the diagnosis code set?

	Inspection chart for diagnosis code (Refer to ).

	Go to Step 2.

STEP 2. Check idling condition.

Q. Is the check result normal?

	Go to Step 3.

	Proceed to troubleshooting for improper idling (Refer to ).

STEP 3. M.U.T.-III data list.

Refer to Data List Reference Table .

Item 5: Barometric pressure sensor
Item 6: Manifold absolute pressure sensor
Item 7: Engine coolant temperature sensor
Item 8: EGR gas temperature sensor
Item 9: Accelerator pedal position sensor (main)
Item 10: Accelerator pedal position sensor (sub)
Item 16: EGR valve position sensor
Item 21: Fuel temperature sensor
Item 43: Intake air temperature sensor
Item 45: Throttle position sensor

Q. Are the check results normal?

	Go to Step 4.

	Perform the diagnosis code classified check procedure for the sensor that has shown an abnormal data value (Refer to Inspection Chart for Diagnosis Code ).

STEP 4. Check injector identification code.

Check injector identification code (Refer to GROUP 00 - Precautions before Service - Injector Identification Code Registration Procedure <4N1> ).

Q. Is the check result normal?

	Go to Step 5.

	Register the injector ID.

STEP 5. Supply pump correction learning.

Carry out the supply pump correction learning (Refer to GROUP 00 - Precautions before Service - Supply Pump Correction Learning Procedure <4N1> ).

Q. Does the trouble symptom persist?

	Go to Step 6.

	Check end.

STEP 6. Small injection quantity learning.

Carry out the small injection quantity learning procedure (Refer to GROUP 00 - Precautions before Service - Small Injection Quantity Learning Procedure <4N1> ).

Q. Does the trouble symptom persist?

	Go to Step 7.

	Check end.

STEP 7. Check the using fuel.

Check for foreign matters (water, petrol fuel, etc.) in fuel.

Q. Is the specified fuel being used?

	Go to Step 8.

	Replace the fuel.

STEP 8. Check engine oil.

Q. Are the oil volume and viscosity normal?

	Go to Step 9.

	Replenish or change engine oil.

STEP 9. M.U.T.-III actuator test.

Refer to Actuator Test Reference Table .

Item 54: Glow (PWM) 0%
Item 55: Glow (PWM) 50%
Item 56: Glow (PWM) 100%

Q. Is the check result normal?

	Go to Step 10.

	Check the glow plug system (Refer to Code No. P0381 ).

STEP 10. Check the EGR cooler bypass control system.

Check the EGR cooler bypass control system (Refer to GROUP 17 - Emission Control <Diesel> - Exhaust Gas Recirculation (EGR) System - EGR Cooler Bypass Control System Check ).

Q. Is the check result normal?

	Go to Step 12.

	Go to Step 11.

STEP 11. M.U.T.-III actuator test.

Item 31: EGR cooler bypass control solenoid valve

OK: Operating sound can be heard and the valve vibrates

Q. Is the check result normal?

	Check the connection condition of the vacuum hoses which can be removed, loosened, clogged possibly. And then check whether there are no folded and damaged vacuum hoses.

	Check the EGR cooler bypass control solenoid valve circuit (Refer to Code No. P2426 , Refer to Code No. P2427 ).

STEP 12. Check the EGR valve vacuum actuator.

Check the EGR valve vacuum actuator [Refer to GROUP 17 - Emission Control <Diesel> - Exhaust Gas Recirculation (EGR) System - EGR Valve (DC Motor) Check ].

Q. Is the check result normal?

	Go to Step 13.

	Replace the EGR valve.

STEP 13. M.U.T.-III actuator test.

Refer to Actuator Test Reference Table .

Item 19: Suction control valve

Q. Is the check result normal?

	Go to Step 14.

	Check suction control valve system (Refer to Code No. P0003 , Refer to Code No. P0004 ).

STEP 14. M.U.T.-III data list.

Refer to Data List Reference Table .

Item 63: Rail pressure sensor
Item 64: Rail pressure target

Q. Are the check results normal?

	Go to Step 17.

	Go to Step 15.

STEP 15. Replace the fuel pressure sensor.

After replacing the common-rail assembly, re-check the trouble symptoms.

Q. Does the trouble symptom persist?

	Go to Step 16.

	Check end.

STEP 16. Check the trouble symptoms.

Q. Does the trouble symptom persist?

	Replace the supply pump assembly.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 17. Check compression pressure.

Check compression pressure (Refer to GROUP 11E - On-vehicle Service - Compression Pressure Check ).

Q. Is the check result normal?

	Go to Step 18.

	Repair.

STEP 18. Check injector itself.

Injector connector check.
Check injector itself (Refer to ).

Q. Is the check result normal?

	Go to Step 19.

	Repair or replace the connector, or replace the injector at the failed cylinder.

STEP 19. Check the turbocharging pressure.

Check the turbocharging pressure (Refer to GROUP 15 - On-vehicle Service - Turbocharger Supercharging Pressure Check ).

Q. Is the check result normal?

	Go to Step 20.

	Repair.

STEP 20. Check EGR valve itself.

EGR valve connector check.
Check EGR valve itself [Refer to GROUP 17 - Emission Control <Diesel> - Exhaust Gas Recirculation (EGR) System - EGR Valve (DC Motor) Check ].

Q. Is the check result normal?

	Go to Step 21.

	Repair or replace the connector, or replace the EGR valve.

STEP 21. Check the trouble symptoms.

Q. Does the trouble symptom persist?

	Replace the engine-ECU.

	Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).