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Section 298 (HVAC - Diagnostics): Pre-Check

WARNING: This page is about a different car, the 2002 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.
  1. Warning For A/C Compressor Lock 

    If compressor lock occurs during A/C operation, the A/C switch indicator on the A/C control assembly starts blinking.

    When this occurs, check for compressor lock (see DTC 22 COMPRESSOR LOCK SENSOR CIRCUIT  and DIAGNOSTIC TROUBLE CODE CHART  ) using diagnosis trouble code check then proceed to inspect the circuit or the component.

    Compressor lock sensor circuit. See DTC 22 COMPRESSOR LOCK SENSOR CIRCUIT .

    Fig 1: A/C Control Assembly Blinking Indicator Graph For 1/2 Second Intervals
    G01118852Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  2. List Of Operation Methods  :

    By operating each of the A/C control switches as shown in the diagram below, it is possible to enter the diagnosis check mode.

    Fig 2: A/C Control Switch Diagnostic Operating Order Diagram
    G01118853Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  3. Indicator Check  :
    1. Turn the ignition switch to on while pressing the A/C control AUTO switch and R/F SW simultaneously.
      Fig 3: Locating A/C Control & R/F SW
      G01118854Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. NOTE:
      • After the indicator check is ended, the diagnostic trouble code check begins automatically.
      • Press the OFF switch when desiring to cancel the check mode.
      Fig 4: Blinking Indicator Graph For 1 Second Intervals
      G01118855Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check that all the indicators light up and go off at 1 second intervals 4 times in succession.
  4. DTC Check (Sensor Check) 
    1. Perform an indicator check. After the indicator check is completed, the system enters the DTC check mode automatically.
    2. Read the DTC displayed on the panel. Refer to the list of DTCs, see DIAGNOSTIC TROUBLE CODE CHART , when reading the DTCs (DTCs are out put at the temperature display, see Fig 5.).

      If the slower display is desired, press the DEF. SW and change it to step operation. Each time the Temp. Control switch is pressed, the display changes by 1 step.

      Fig 5: Locating Temperature Display
      G01118856Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 6: Locating Defrost Switch
      G01118857Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  5. Clearing DTC: 
    1. Pull out the DOME fuse in engine room J/B for 10 sec. or longer to clear the diagnostic DTC's memory.
    2. After reinserting the fuse, check that the normal code is output.
      Fig 7: Locating Dome Fuse
      G01118858Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  6. Actuator Check  :
    1. After entering the sensor check mode, press the R/F switch.
      Fig 8: Locating R/F Switch
      G01118859Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      2. NOTE:
      • Code are displayed in order from the smaller to the larger numbers.
      • To cancel the check mode, press the OFF switch.
      Fig 9: Corresponding DTC's For Damper, Motor & Relay Automatic Operation Chart
      G01118861Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      Fig 10: Locating Defrost Switch
      G01118860Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Since each damper, motor and relay automatically operates at 1 second intervals beginning in order from 20 in the temperature display, check the temperature and air flow visually and by hand.

      If a slower display is desired, press the DEF. (Fr.) switch and change it to step operation. Each time the DEF. (Fr.) switch is pressed, the display changes by 1 step.

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