AIR CONDITIONING SYSTEM HOW TO PROCEED WITH TROUBLESHOOTING

Tech Tips


  • Use the following procedure to troubleshoot the air conditioning system.

  • *: Use the intelligent tester.


  1. VEHICLE BROUGHT TO WORKSHOP


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  2. INSPECT BATTERY VOLTAGE


    1. Inspect the battery voltage with the power switch off.

      Standard Voltage
      11 to 14 V

      If the voltage is below 11 V, recharge or replace the battery before proceeding to the next step.


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  3. CHECK COMMUNICATION FUNCTION OF LIN COMMUNICATION SYSTEM*


    1. Use the intelligent tester to check if the LIN communication system is functioning normally.

      Result
      Result Proceed to
      LIN DTC is not output A
      LIN DTC is output

      B

      Click here


      B
      A
  4. CHECK COMMUNICATION FUNCTION OF CAN COMMUNICATION SYSTEM*


    1. Use the intelligent tester to check if the CAN communication system is functioning normally.

      Result
      Result Proceed to
      CAN DTC is not output A
      CAN DTC is output

      B

      Click here


      B
      A
  5. CHECK FOR DTC*


    1. Check for DTCs and note any code that is output.

    2. Clear the DTCs.

    3. Recheck for DTCs. Based on the DTCs output above, try to force the A/C system to output DTCs by simulating the conditions indicated by the DTC.

      Result
      Result Proceed to
      DTC is output A
      DTC is not output B

      B
      A
  6. DIAGNOSTIC TROUBLE CODE CHART


    1. Find the output code in Diagnostic Trouble Code Chart Click here.


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  7. PROBLEM SYMPTOMS TABLE


    1. Refer to Problem Symptoms Table Click here.

      Result
      Result Proceed to
      Fault is not listed in Problem Symptoms Table A
      Fault is listed in Problem Symptoms Table B

      B
      A
  8. OVERALL ANALYSIS AND TROUBLESHOOTING*


    1. Panel diagnosis (indicator check, sensor check) Click here

    2. Data List / Active Test Click here

    3. Terminals of ECU Click here

    4. On-vehicle Inspection

    5. Inspection


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  9. ADJUST, REPAIR OR REPLACE


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