Inspection Procedure 14: The Engine Stalls when Decelerating <FFV>

COMMENT ON TROUBLE SYMPTOM

Engine stall on deceleration is possibly caused by insufficient air intake, improper air-fuel ratio due to failed exhaust gas recirculation system or other faults.

PROBABLE CAUSES

Estimated ethanol concentration not learned
Failed throttle valve control
Failed ignition system
Failed emission control system
Throttle valve fouled around
Failed engine-ECU

DIAGNOSIS PROCEDURE

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

Q. 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 No. 11: Accelerator pedal position sensor (main)
Item No. 12: Accelerator pedal position sensor (sub)
Item No. 13: Throttle position sensor (main)
Item No. 14: Throttle position sensor (sub)

Q. Are the check result 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. Forced learning of estimated ethanol concentration execution

Carry out the estimated ethanol concentration forcible learning (Refer to GROUP 00 - Precautions Before Service - Forced Learning of Estimated Ethanol Concentration ), reconfirm whether the trouble symptom.

Q. Does trouble symptom persist?

	Go to Step 4 .

	Check end.

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. Visual check of ignition spark.

Remove the spark plug and install to the ignition coil.
Connect the ignition coil connector.
Remove all injector connectors.
At the engine start, check each spark plug procedure a spark.

Q. Is the check result normal?

	Replace the engine-ECU then perform the variant coding (Refer to GROUP 00 - Precautions Before Service - How to Perform Variant Coding ).

	Check ignition circuit system (Refer to Inspection Procedure 39 ).