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Diagnosis System

WARNING: This page is about a different car, the 2012 Toyota Corolla. However, it is still accessible from the selected car via links, so may be relevant.
  1. DESCRIPTION 
    1. Air conditioning system data and the Diagnostic Trouble Codes (DTCs) can be read through the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform troubleshooting.
  2. CHECK DLC3 
    1. Check the DLC3. Refer to GENERAL INFORMATION .
  3. LIST OF OPERATION METHODS 
    1. By operating each of the air conditioning control switches as shown in the diagram below, it is possible to enter the diagnostic check mode.
      Fig 1: Air Conditioning Control Switches Operation Diagram
      GTY208648Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  4. INDICATOR CHECK 
    1. Turn the ignition switch off.
    2. Turn the ignition switch to ON while pressing the A/C control assembly "AUTO" switch and "R/F" switch simultaneously. Hold both switches until the indicator check screen appears.
      Fig 2: AUTO Switch And R/F Switch - Screen Display
      GTY207582Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. The indicator check is automatically performed when panel diagnosis is activated. Check that the indicators light up and go off at 1 second intervals 4 times in succession.
      Fig 3: Identifying A/C Control Assembly Indicator Blinking Pattern
      GTY207587Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      • The sensor check automatically starts when the indicator check is completed.
      • Press the "OFF" switch to cancel the check mode.
      • If a navigation system is installed, the indicator will blink and the buzzer will sound.
  5. SENSOR CHECK (DTC CHECK) 
    1. Start the engine and warm it up.
    2. Perform the indicator check.

      HINT: 

      After the indicator check is completed, the system enters the DTC check mode automatically.

    3. Read the DTC displayed on the panel.
      Fig 4: A/C Control Assembly And DTC - Screen Display
      GTY177662Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      NOTE:
      • In the sensor check mode, which is automatically entered after indicator check mode, troubleshooting may be partially performed. Be sure to perform the actuator and sensor checks again.
      • If the check is performed in a dark place, DTC 21 may be displayed even though the system is normal.

      HINT: 

      Refer to the DTC chart (Diagnostic Trouble Code chart) for details of the codes. Refer to DIAGNOSTIC TROUBLE CODE CHART .

      • When there are no problems, DTC 00 is output.
      • As an example, the illustration shows that display code 21 is output.
    4. If the steps are difficult to read because they change automatically, push the "DEF" switch to display the steps one at a time so that they can be read easily. The items are displayed step by step each time the "DEF" switch is pushed.
      Fig 5: Push DEF Switch - Screen Display
      GTY207586Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      • Push the "OFF" switch to finish panel diagnosis.
      • Push the "R/F" switch to enter the actuator check mode.
    5. Clear the DTC
      Fig 6: Press DEF Switch And Rear DEF Switch - Screen Display
      GTY207583Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      1. During the sensor check, press the "DEF" switch and "REAR DEF" switch at the same time.
  6. ACTUATOR CHECK 
    1. Start the engine and warm it up.
    2. Perform the indicator check.
    3. Push the "R/F" switch to perform the actuator check.
      Fig 7: Push R/F Switch - Screen Display
      GTY207584Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      Be sure to perform the actuator check after starting the engine.

    4. As the actuator check is repeated from steps 1 to 10 at 1 second intervals, check the temperature and air flow visually and by hand.
      Fig 8: Push AUTO Switch - Screen Display
      GTY207585Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      • The display blinks at 1 second intervals in the step operation.
      • Push the "OFF" switch to finish panel diagnosis.
      • Push the "AUTO" switch to enter the sensor check mode.
      Step No. Display Code Condition
      Blower Level Air Mix Damper Airflow Vent Air Inlet Damper Compressor
      1 0 0 0% open FACE FRESH OFF
      2 1 1 0% open FACE FRESH OFF
      3 2 17 0% open FACE RECIRCULATION/FRESH ON
      4 3 17 0% open FACE RECIRCULATION ON
      5 4 17 50% open B/L RECIRCULATION ON
      6 5 17 50% open B/L RECIRCULATION ON
      7 6 17 50% open FOOT FRESH ON
      8 7 17 100% open FOOT-0 FRESH ON
      9 8 17 100% open F/D FRESH ON
      10 9 31 100% open DEF FRESH ON
    5. If the steps are difficult to read because they change automatically, push the "DEF" switch to display the steps one at a time so that they can be read easily. The items are displayed step by step each time the "DEF" switch is pushed.
      Fig 9: Push DEF Switch - Screen Display
      GTY207586Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT: 

      • Push the "OFF" switch to finish panel diagnosis.
      • Push the "R/F" switch to enter the sensor check mode.