Description

CHART 6: ENGINE IDLE SPEED TOO LOW OR UNSTABLE

Diagnosis Procedure

1.CHECK FUEL

Check that the fuel reservoir is correctly filled and with the right fuel.

>> GO TO 2.

2.CHECK ECM POWER SUPPLY AND GROUND CIRCUIT

Check ECM power supply and ground circuit. Refer to EC-885, "Diagnosis Procedure".

Is the inspection result normal? YES >> GO TO 3.

NO >> Repair or replace harness or connector.

3.CHECK WIRING HARNESS

Visually check the condition of the engine wiring harness.

Is the inspection result normal? YES >> GO TO 4.

NO >> Repair or replace harness or connector.

4.CHECK AIR INTAKE SYSTEM

Check air intake system. Refer to EM-280, "Removal and Installation".

Is the inspection result normal? YES >> GO TO 5.

NO >> Repair or replace air intake system. Refer to EM-280, "Removal and Installation".

5.CHECK ELECTRIC THROTTLE CONTROL ACTUATOR

Check electric throttle control actuator. Refer to EC-909, "Diagnosis Procedure".

Is the inspection result normal? YES >> GO TO 6.

NO >> Repair or replace.

6.CHECK MASS AIR FLOW SENSOR

Check mass air flow sensor. Refer to EC-902, "Component Inspection".

Is the inspection result normal? YES >> GO TO 7.

NO >> Repair or replace.

7.CHECK REFRIGERANT PRESSURE SENSOR

Check refrigerant pressure sensor. Refer to EC-960, "Diagnosis Procedure".

Is the inspection result normal? YES >> GO TO 8.

NO >> Repair or replace.

8.CHECK EGR SYSTEM

Check EGR system. Refer to EC-954, "Diagnosis Procedure".

Is the inspection result normal? YES >> GO TO 9.

NO >> Repair or replace.

9.CHECK CATALYTIC CONVERTER

Is the catalytic converter clogged or deteriorated?

Is the inspection result normal? YES >> GO TO 10.

NO >> Repair or replace.

10.CHECK LOW PRESSURE CIRCUIT

Perform the TEST 1: LOW PRESSURE CIRCUIT CHECK. Refer to EC-867, "Work Procedure (TEST 1: Low Pressure Fuel Supply System Check)".

>> GO TO 11.

11.CHECK INTERNAL FUEL TRANSFER PUMP

Perform the TEST 2: INTERNAL FUEL TRANSFER PUMP CHECK. Refer to EC-868, "Work Procedure (TEST 2: Internal Fuel Transfer Pump Check)".

>> GO TO 12.

12.CHECK HIGH PRESSURE SUPPLY PUMP (PRESSURE CONTROL VALVE)

Perform the TEST 3: HIGH PRESSURE SUPPLY PUMP (PRESSURE CONTROL VALVE). Refer to EC-868, "Work Procedure [TEST 3: High Pressure Supply Pump (Pressure Control Valve) Check]".

>> GO TO 13.

13.CHECK HIGH PRESSURE SUPPLY PUMP (VOLUMETRIC CONTROL VALVE)

Perform the TEST 4: HIGH PRESSURE SUPPLY PUMP (VOLUMETRIC CONTROL VALVE). Refer to EC- 869, "Work Procedure [TEST 4: High Pressure Supply Pump (Volumetric Control Valve) Check]".

>> GO TO 14.

14.CHECK RAIL HIGH PRESSURE CONTROL CIRCUIT

Perform the TEST 5: RAIL HIGH PRESSURE CONTROL CIRCUIT CHECK. Refer to EC-871, "Work Procedure (TEST 5: Rail High Pressure Regulation Check)".

>> GO TO 15.

15.CHECK MAJOR LEAK IN FUEL INJECTOR/FUEL INJECTORS OPEN

Perform the TEST 6: MAJOR LEAK IN FUEL INJECTOR/FUEL INJECTORS OPEN. Refer to EC-876, "Work Procedure (TEST 6: Fuel Injectors Leak Check)".

>> GO TO 16.

16.CHECK INCORRECT FUEL INJECTION QUANTITY

Perform the TEST 7: INCORRECT FUEL INJECTION QUANTITY. Refer to EC-877, "Work Procedure (TEST 7: Fuel Injection Quantity Check)".

>> INSPECTION END