Inspection Procedure 13: Knocking


COMMENTS ON TROUBLE SYMPTOM



  • Failure is possibly caused by failed detonation control system and improper thermal value of the spark plug

PROBABLE CAUSES



  • Failed detonation sensor
  • Failed detonation control system
  • Failed spark plug
  • Failed ignition system
  • Failed engine-A/T-ECU

DIAGNOSIS PROCEDURE

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

Q. Is the diagnosis code set?
Inspection chart for diagnosis code (Refer to ).
Go to Step 2 .

STEP 2. 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-A/T-ECU.
Go to Step 3 .

STEP 3. Check spark plug

  • Check spark plug itself (Refer to GROUP 16 - Ignition System - On-vehicle Service - Spark plug Check and Cleaning ).

Q. Is the check result normal?
Check ignition circuit system (Refer to Inspection Procedure 25 ).
Replace the spark plug.