Inspection Procedure 12: Hesitation, Sag, Poor Acceleration, Stumble, Surge

COMMENT ON TROUBLE SYMPTOM

Failure is possibly caused by failed ignition system, improper air-fuel ratio, throttle valve opening control system improper compression pressure or other faults.

PROBABLE CAUSE

Failed air-fuel ratio control system

Failed ignition system

Failed fuel system

Failed intake and exhaust system

Failed emission control system

Failed throttle valve opening control system

Throttle valve fouled

Improper compression pressure

Failed engine-A/T-ECU

DIAGNOSIS PROCEDURE

STEP 1. MUT-II/III diagnosis code

Q: Diagnosis code set?

YES: Inspection chart for diagnosis code (Refer to

).
NO: Go to Step 2

STEP 2. Check injector for operating sound.

Check injector for operating sound (Refer to ).

Q: Can operating sound be heard?

YES: Go to Step 3

.
NO:

Check the injector system of the defective cylinder.

(Refer to Code No. P0201: No. 1 Injector System ).

(Refer to Code No. P0202: No. 2 Injector System ).

(Refer to Code No. P0203: No. 3 Injector System ).

(Refer to Code No. P0204: No. 4 Injector System ).

STEP 3. MUT-II/III data list

Refer to Data list reference table .

Idem 13: Intake air temperature sensor

Item 14: Throttle position sensor (sub)

Item 21: Engine coolant temperature sensor

Item 77: Accelerator pedal position sensor (sub)

Item 78: Accelerator pedal position sensor (main)

Item 79: Throttle position sensor (main)

Item 95: Manifold absolute pressure sensor

Q: Are the check results normal?

YES: Go to Step 4

.
NO: 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: MUT-II/III data list

Refer to Data List Reference Table .

Item 25: Barometric pressure sensor

Q: Are the check results normal?

YES: Go to Step 5

.
NO: Replace engine-A/T-ECU.

STEP 5. Check purge control solenoid valve itself.

Check purge control solenoid valve itself (Refer to GROUP 17 - Emission Control System - Evaporative Emission Control System- Purge Control Solenoid Valve Check ).

Q: Is the check result normal?

YES: Go to Step 6

.
NO: Replace purge control solenoid valve.

STEP 6. Check EGR valve (stepper motor) itself.

Check EGR valve (stepper motor) itself [Refer to GROUP 17 - Emission Control System - Exhaust Gas Recirculation (EGR) System - EGR Valve (Stepper Motor) Check <4G69>].

Q: Is the check result normal?

YES: Go to Step 7

.
NO: Replace EGR valve (stepper motor).

STEP 7. MUT-II/III data list

Refer to Data List Reference Table .

Item 11: Oxygen sensor

Item 39: Cylinder 2, 3 oxygen sensor (front) <Vehicles for Hong kong>

Item 59: Oxygen sensor

Item 69: Cylinder 2, 3 oxygen sensor (rear) <Vehicles for Hong kong>

Q: Is the check result normal?

YES: Go to Step 8

.
NO: 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 8. Check ignition coil spark.

Q: Is the check result normal?

YES: Go to Step 9

.
NO: Check ignition circuit system (Refer to Inspection Procedure 30

STEP 9. Check throttle body (throttle valve portion) for contamination.

Q: Is the check result normal?

YES: Go to Step 10

.
NO: Clean throttle body (throttle valve portion) (Refer to

STEP 10. Measure fuel pressure.

Measure fuel pressure (Refer to ).

Q: Is the check result normal?

YES: Go to Step 11

.
NO: Repair.

STEP 11. Check compression pressure.

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

Q: Is the check result normal?

YES: Replace engine-A/T-ECU.
NO: Repair.


Inspection Procedure 12: Hesitation, Sag, Poor Acceleration, Stumble, Surge

COMMENT ON TROUBLE SYMPTOM Failure is possibly caused by failed ignition system, improper air-fuel ratio, throttle valve opening control system improper compression pressure or other faults.
PROBABLE CAUSE Failed air-fuel ratio control system Failed ignition system Failed fuel system Failed intake and exhaust system Failed emission control system Failed throttle valve opening control system Throttle valve fouled Improper compression pressure Failed engine-A/T-ECU
	DIAGNOSIS PROCEDURE

	STEP 1. MUT-II/III diagnosis code Q: Diagnosis code set? YES: Inspection chart for diagnosis code (Refer to ). NO: Go to Step 2 .
	STEP 2. Check injector for operating sound. Check injector for operating sound (Refer to ). Q: Can operating sound be heard? YES: Go to Step 3 . NO: Check the injector system of the defective cylinder. (Refer to Code No. P0201: No. 1 Injector System ). (Refer to Code No. P0202: No. 2 Injector System ). (Refer to Code No. P0203: No. 3 Injector System ). (Refer to Code No. P0204: No. 4 Injector System ).
	STEP 3. MUT-II/III data list Refer to Data list reference table . Idem 13: Intake air temperature sensor Item 14: Throttle position sensor (sub) Item 21: Engine coolant temperature sensor Item 77: Accelerator pedal position sensor (sub) Item 78: Accelerator pedal position sensor (main) Item 79: Throttle position sensor (main) Item 95: Manifold absolute pressure sensor Q: Are the check results normal? YES: Go to Step 4 . NO: 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: MUT-II/III data list Refer to Data List Reference Table . Item 25: Barometric pressure sensor Q: Are the check results normal? YES: Go to Step 5 . NO: Replace engine-A/T-ECU.
	STEP 5. Check purge control solenoid valve itself. Check purge control solenoid valve itself (Refer to GROUP 17 - Emission Control System - Evaporative Emission Control System- Purge Control Solenoid Valve Check ). Q: Is the check result normal? YES: Go to Step 6 . NO: Replace purge control solenoid valve.
	STEP 6. Check EGR valve (stepper motor) itself. Check EGR valve (stepper motor) itself [Refer to GROUP 17 - Emission Control System - Exhaust Gas Recirculation (EGR) System - EGR Valve (Stepper Motor) Check <4G69>]. Q: Is the check result normal? YES: Go to Step 7 . NO: Replace EGR valve (stepper motor).
	STEP 7. MUT-II/III data list Refer to Data List Reference Table . Item 11: Oxygen sensor Item 39: Cylinder 2, 3 oxygen sensor (front) <Vehicles for Hong kong> Item 59: Oxygen sensor Item 69: Cylinder 2, 3 oxygen sensor (rear) <Vehicles for Hong kong> Q: Is the check result normal? YES: Go to Step 8 . NO: 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 8. Check ignition coil spark. Q: Is the check result normal? YES: Go to Step 9 . NO: Check ignition circuit system (Refer to Inspection Procedure 30 ).
	STEP 9. Check throttle body (throttle valve portion) for contamination. Q: Is the check result normal? YES: Go to Step 10 . NO: Clean throttle body (throttle valve portion) (Refer to ).
	STEP 10. Measure fuel pressure. Measure fuel pressure (Refer to ). Q: Is the check result normal? YES: Go to Step 11 . NO: Repair.
	STEP 11. Check compression pressure. Check compression pressure (Refer to GROUP 11E - On-vehicle Service - Compression Pressure Check ). Q: Is the check result normal? YES: Replace engine-A/T-ECU. NO: Repair.