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PTC Heater Circuit [11/2021 - 03/2023]: Procedure

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  1. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY 
    1. Disconnect the D52 and D53 air conditioning amplifier assembly connectors.
      GTY1071263Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Air Conditioning Amplifier Assembly)      		 - -
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      D52-23 (PTC1) - Body ground Ignition switch off → ON Below 1 V → 11 to 14 V
      D53-16 (PTC2) - Body ground Ignition switch off → ON Below 1 V → 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  8

    Result: 

    OK 

    See step  2

  2. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY 
    1. Connect the D52 and D53 air conditioning amplifier assembly connectors.
      GTY1068152Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Air Conditioning Amplifier Assembly)      		 - -
    2. Perform the Active Test according to the display on the GTS.

      Body Electrical > Air Conditioner > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      PTC Heater This test activates the PTC Heater.
      (PTC heater (quick heater assembly))      		 0: Min.
      3: Max.      		 Operate with the ignition switch ON (READY) and the vehicle stopped.

      Body Electrical > Air Conditioner > Active Test 

      Tester Display
      PTC Heater
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      D52-23 (PTC1) - Body ground
      • Perform Active Test and select "OFF" → "ON" item
      • Heater level is 1
      		 11 to 14 V → Below 1 V
      D53-16 (PTC2) - Body ground
      • Perform Active Test and select "OFF" → "ON" item
      • Heater level is 2
      		 11 to 14 V → Below 1 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [11/2021 - ] 

    Result: 

    OK 

    See step  3

  3. CHECK PTC HEATER (QUICK HEATER ASSEMBLY) 
    1. Disconnect the D139 and D140 PTC heater (quick heater assembly) connectors.
      GTY1070627Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to PTC Heater (Quick Heater Assembly))      		 - -
    2. Perform the Active Test according to the display on the GTS.

      Body Electrical > Air Conditioner > Active Test 

      Tester Display Measurement Item Control Range Diagnostic Note
      PTC Heater This test activates the PTC Heater.
      (PTC heater (quick heater assembly))      		 0: Min.
      3: Max.      		 Operate with the ignition switch ON (READY) and the vehicle stopped.

      Body Electrical > Air Conditioner > Active Test 

      Tester Display
      PTC Heater
    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      D139-2 - Body ground
      • Perform Active Test and select "OFF" → "ON" item
      • Heater level is 1
      		 Below 1 V → 11 to 14 V
      D140-1 - Body ground
      • Perform Active Test and select "OFF" → "ON" item
      • Heater level is 1
      		 Below 1 V → 11 to 14 V
      D140-3 - Body ground
      • Perform Active Test and select "OFF" → "ON" item
      • Heater level is 2
      		 Below 1 V → 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  5

    Result: 

    OK 

    See step  4

  4. CHECK HARNESS AND CONNECTOR (PTC HEATER (QUICK HEATER ASSEMBLY) - BODY GROUND) 
    1. Disconnect the D139 and D140 PTC heater (quick heater assembly) connectors.
      GTY1070627Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to PTC Heater (Quick Heater Assembly))      		 - -
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      D139-1 - Body ground Always Below 1 Ω
      D140-2 - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE PTC HEATER (QUICK HEATER ASSEMBLY). Refer to  REMOVAL [11/2021 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  5. INSPECT PTC HEATER RELAY (PTC HTR NO. 1 and PTC HTR NO. 2) 

    Refer to ON-VEHICLE INSPECTION [11/2021 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE PTC HEATER RELAY (PTC HTR NO. 1 and PTC HTR NO. 2) 

    Result: 

    OK 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - POWER SOURCE) 
    1. Remove the PTC heater relays (PTC HTR NO. 1 and PTC HTR NO. 2) from the No. 2 engine room relay block assembly.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      PTC HTR NO. 1 RELAY

      Tester Connection Switch Condition Specified Condition
      Relay terminal 3 - Body ground Always 11 to 14 V
      PTC HTR NO. 2 RELAY

      Tester Connection Switch Condition Specified Condition
      Relay terminal 3 - Body ground Always 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - PTC HEATER (QUICK HEATER ASSEMBLY)) 
    1. Remove the PTC heater relays (PTC HTR NO. 1 and PTC HTR NO. 2) from the No. 2 engine room relay block assembly.
    2. Disconnect the D139 and D140 PTC heater (quick heater assembly) connectors.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      PTC HTR NO. 1 RELAY

      Tester Connection Condition Specified Condition
      Relay terminal 5 - D139-2 Always Below 1 Ω
      Relay terminal 5 - D140-1 Always Below 1 Ω
      Relay terminal 5, D139-2 or D140-1 - Other terminals and body ground Always 10 kΩ or higher
      PTC HTR NO. 2 RELAY

      Tester Connection Condition Specified Condition
      Relay terminal 5 - D140-3 Always Below 1 Ω
      Relay terminal 5 or D140-3 - Other terminals and body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [11/2021 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  8. INSPECT PTC HEATER RELAY (PTC HTR NO. 1 and PTC HTR NO. 2) 

    Refer to ON-VEHICLE INSPECTION [11/2021 - ]

    Result

    Proceed to
    OK
    NG

    Result: 

    NG 

    REPLACE PTC HEATER RELAY (PTC HTR NO. 1 and PTC HTR NO. 2) 

    Result: 

    OK 

    See step  9

  9. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - POWER SOURCE) 
    1. Remove the PTC heater relays (PTC HTR NO. 1 and PTC HTR NO. 2) from the No. 2 engine room relay block assembly.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      PTC HTR NO. 1 RELAY

      Tester Connection Switch Condition Specified Condition
      Relay terminal 2 - Body ground Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V
      PTC HTR NO. 2 RELAY

      Tester Connection Switch Condition Specified Condition
      Relay terminal 2 - Body ground Ignition switch off Below 1 V
      Ignition switch ON 11 to 14 V

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  10

  10. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - AIR CONDITIONING AMPLIFIER ASSEMBLY) 
    1. Remove the PTC heater relays (PTC HTR NO. 1 and PTC HTR NO. 2) from the No. 2 engine room relay block assembly.
    2. Disconnect the D52 and D53 air conditioning amplifier assembly connectors.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      PTC HTR NO. 1 RELAY

      Tester Connection Condition Specified Condition
      Relay terminal 1 - D52-23 (PTC1) Always Below 1 Ω
      Relay terminal 1 or D52-23 (PTC1) - Other terminals and body ground Always 10 kΩ or higher
      PTC HTR NO. 2 RELAY

      Tester Connection Condition Specified Condition
      Relay terminal 1 - D53-16 (PTC2) Always Below 1 Ω
      Relay terminal 1 or D53-16 (PTC2) - Other terminals and body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY. Refer to  REMOVAL [11/2021 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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