Customer Problem Analysis

HINT: 

• When troubleshooting, confirm that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred.
• Gather as much information as possible for reference. Past problems that seem unrelated may also help in some cases.

• The following 5 items are important points for problem analysis:

  What	Vehicle model, system name
  When	Date, time, occurrence frequency
  Where	Road conditions
  Under what conditions?	Driving conditions, weather conditions
  How did it happen?	Problem symptoms

1. 1. DTC CHECK 
2. 2. MAKE A NOTE OF DTC DISPLAYED AND THEN CLEAR DTCs 
3. 3. SYMPTOM CONFIRMATION 

   Result

   Result	Proceed to
   No symptoms exist	Go to step 4
   Symptoms exist	Go to step 5

4. 4. SIMULATION TEST USING SYMPTOM SIMULATION METHODS 
5. 5. DTC CHECK 

   Result

   Result	Proceed to
   DTCs are not output	Go to step 6
   DTCs are output	TROUBLESHOOT FOR PROBLEM INDICATED BY DTC

6. 6. SYMPTOM CONFIRMATION 

   Result

   Result	Proceed to
   Symptoms exist	TROUBLESHOOT FOR EACH PROBLEM SYMPTOM
   No symptoms exist	END

   If a DTC was displayed in the initial DTC check, the problem may have occurred in a wire harness or connector in that circuit in the past. Check the wire harness and connectors.