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, failed electronic-controlled throttle valve system and so on.

PROBABLE CAUSES

Failed ignition system
Failed electronic-controlled throttle valve system
Contamination around the throttle valve
Failed CVT <CVT>
Failed engine-ECU

DIAGNOSIS PROCEDURE

note

<CVT>
To protect the CVT, the CVT-ECU outputs, into the engine-ECU, the request signal to reduce the engine torque according to the operation condition, Based on the signal, the engine-ECU closes the throttle valve, retards the ignition or carries out fuel cut. At that time, the engine output seems to temporarily reduce, but there is no malfunction.

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

Q. Is the diagnosis code set?

	Inspection chart for diagnosis code (Refer to ).

	NO : Go to Step 3 <M/T>.

	NO : Go to Step 2 <CVT>.

STEP 2. M.U.T.-III diagnosis code

note

When the CVT has a malfunction, the CVT-ECU might output the request signal of reducing the engine torque in order to protect the CVT.

Confirm the diagnosis code is set from CVT-ECU.

Q. Is the diagnosis code set?

	Perform troubleshooting of CVT System (Refer to GROUP 23A - Troubleshooting - Diagnosis Code Chart ).

	Go to Step 3.

STEP 3. 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?

	YES : Go to Step 4.

	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. Check throttle body (throttle valve portion) 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 it to the ignition coil.
Connect the ignition coil connector.
Disconnect all injector connectors.
At the engine start, check each spark plug produces a spark.

Q. Is the check result normal?

	Replace the engine-ECU.

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