Inspection Procedure 9: Poor Acceleration <EURO5>

PROBABLE CAUSES

Failed supercharging pressure control system
Failed turbocharger
Improper fuel used
Fuel contaminated with foreign matter
Injector leaking or clogged
Failed injector
Fuel filter clogged
Fuel line leaking or clogged
Failed fuel pressure sensor
Failed supply pump (suction control valve)
Failed EGR system operation
Compression pressure low
Air cleaner clogged
Failed engine-ECU

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 air cleaner.

Q. Is the check result normal?

	Go to Step 5.

	Replace the air cleaner.

STEP 5. Check the using fuel.

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

Q. Is the specified fuel being used?

	Go to Step 6.

	Replace the fuel.

STEP 6. 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 7.

	Repair.

STEP 7. Check fuel supply line.

Check for fuel leakage and clogging.
Check fuel filter for clogging.

Q. Is the check result normal?

	Go to Step 8.

	Repair.

STEP 8. 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 9.

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

STEP 9. 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 12.

	Go to Step 10.

STEP 10. 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 11.

	Check end.

STEP 11. 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 12. M.U.T.-III actuator test.

Refer to Actuator Test Reference Table .

Item 15: Injector No. 1
Item 16: Injector No. 2
Item 17: Injector No. 3
Item 18: Injector No. 4

Q. Are the check results normal?

	Go to Step 13.

	Check the injector system of the defective cylinder. (Refer to Code No. P0201: No. 1 Injector Circuit Malfunction ). (Refer to Code No. P0202: No. 2 Injector Circuit Malfunction ). (Refer to Code No. P0203: No. 3 Injector Circuit Malfunction ). (Refer to Code No. P0204: No. 4 Injector Circuit Malfunction ).

STEP 13. Check injector itself.

Injector connector check.
Check injector itself (Refer to On-vehicle Service - Injector Check).

Q. Is the check result normal?

	Go to Step 14.

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

STEP 14. 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 15.

	Repair.

STEP 15. Check exhaust gas recirculation valve itself.

Exhaust gas recirculation valve connector check.
Check exhaust gas recirculation valve itself [Refer to GROUP 17 - Emission Control <Diesel> - Exhaust Gas Recirculation (EGR) System <4N1> - exhaust gas recirculation valve (DC Motor) Check ].

Q. Is the check result normal?

	Go to Step 16.

	Repair or replace the connector, or replace the exhaust gas recirculation valve.

STEP 16. 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).