Inspection Procedure 9. The Engine Stalls when Decelerating

COMMENT ON TROUBLE SYMPTOM

Failure is possibly caused by insufficient air intake, improper air-fuel ratio due to failed exhaust gas recirculation system and so on.

PROBABLE CAUSE

Failed throttle valve control system
Failed ignition system
Failed exhaust control system
Contamination of throttle body (throttle valve portion)
Failed engine-A/T-ECU

DIAGNOSIS PROCEDURE

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

Q. Is diagnosis code set?

	Inspection chart for diagnosis code (Refer to ).

	Go to Step 2 .

STEP 2. M.U.T.-III data list

Refer to Data List Reference Table. .

Item 14: Throttle position sensor (sub)
Item 77: Accelerator pedal position sensor (sub)
Item 78: Accelerator pedal position sensor (main)
Item 79: Throttle position sensor (main)

Q. Are the check results normal?

	Go to Step 3 .

	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 3. 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 ].

Q. Is the check result normal?

	Go to Step 4 .

	Replace EGR valve (stepper motor).

STEP 4. Check throttle body (throttle valve portion) for contamination.

Q. Is the check result normal?

	Go to Step 5 .

	Clean throttle body (throttle valve portion) (Refer to ).

STEP 5. Check spark plug.

Q. Is the check result normal?

	Go to Step 6 .

	Replace spark plug.

STEP 6. Check ignition coil spark.

Q. Is the check result normal?

	Replace engine-A/T-ECU.

	Check ignition circuit system (Refer to Inspection Procedure 26 ).