Inspection Procedure 12: The feeling of impact or vibration when accelerating

COMMENTS ON TROUBLE SYMPTOM

Failure is possibly caused by ignition leak occurring in association with the increase of required voltage by the spark plug at an acceleration and failed electronic-control throttle valve system, and so on.

PROBABLE CAUSES

Failed ignition system
Failed electronic control throttle valve system
Contamination around the throttle valve
Failed engine-ECU <M/T> or engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

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

Q. Is the check result normal?

	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 11: Accelerator pedal position sensor (main)
Item 12: Accelerator pedal position sensor (sub)
Item 13: Throttle position sensor (main)
Item 15: Throttle position sensor (sub)

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 throttle body (throttle valve portion) contamination.

Q. Is the check result normal?

	Go to Step 4 .

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

STEP 4. Visual check of ignition spark.

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

Q. Is the check result normal?

	Replace the engine-ECU <M/T> or engine-A/T-ECU <A/T>.

	Go to Step 5 .

STEP 5. Check spark plug

Check spark plug itself (Refer to GROUP 16 - Ignition System - On-vehicle Service - Spark Plug Check and Cleaning <6G72 without catalytic converter> or Spark Plug Check and Cleaning <6G72 with catalytic converter> ).

Q. Is the check result normal?

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

	Replace the spark plug.