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Inspection Procedure 5: Knocking
 
 
 
 
COMMENT
Incases such as the above, the cause is probably that the knocking control is defective or the heat value of the spark plug is inappropriate.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this case:)
  • Defective knock sensor.
  • Incorrect heat value of the spark plug.
  • Poor compression.
  • Contaminated fuel.
  • ECM failed.
 
 
DIAGNOSIS
Required Special Tools:
  • MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite main harness A
  • MB992747: V.C.I.-Lite USB cable short
  • MB992748: V.C.I.-Lite USB cable long
1.STEP 1. Using scan tool (M.U.T.-III SE), read the DTC.
Use scan tool (M.U.T.-III SE) to check and see if a DTC is set in the ECM (Refer to HOW TO READ AND ERASE DIAGNOSTIC TROUBLE CODES).
Q: Is any DTC set?
Perform troubleshooting for the set DTC (Refer to DIAGNOSTIC TROUBLE CODE CHART).
 
2.STEP 2. Using scan tool (M.U.T.-III SE), check the data list.
Use scan tool (M.U.T.-III SE) to check the data list (Refer to DATA LIST REFERENCE TABLE).
  • Item number 170: Learned Knock
Q: Is the check result normal?
Perform troubleshooting for the knock sensor circuit [Refer to DTC P0327-00: Detonation Sensor circuit low input DTC P0327-00: Detonation Sensor circuit low input), and Refer to DTC P0328-00: Detonation Sensor circuit high input DTC P0328-00: Detonation Sensor circuit high input)].
 
3.STEP 3. Check the spark plug.
Check the number 1 cylinder spark plug, number 2 cylinder spark plug, number 3 cylinder spark plug and number 4 cylinder spark plug itself (Refer to ENGINE , Engine Electrical – On-vehicle Service SPARK PLUG CHECK AND CLEANING).
Q: Are the check result normal?
Replace the faulty spark plug (Refer to ENGINE , Engine Electrical – Ignition Coil IGNITION COIL REMOVAL AND INSTALLATION).
 
4.STEP 4. Check the compression pressure.
Check the compression pressure (Refer to ENGINE, Engine Mechanical – Engine Adjustment COMPRESSION PRESSURE CHECK ).
Q: Is the check result normal?
Repair it.
 
5.STEP 5. Check fuel.
Check for entry of foreign matter (water, kerosene, etc.) into fuel.
Q: Is the check result normal?
Replace the fuel.
 
6.STEP 6. Check the malfunction symptoms.
Q: Does the malfunction symptom persist?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION).
Intermittent malfunction (Refer to GENERAL INFORMATION, General Information – How to Use Troubleshooting/Inspection Service Points HOW TO COPE WITH INTERMITTENT MALFUNCTIONS).