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Inspection Procedure

  1. CHECK FREEZE FRAME DATA 
    1. Check the information code from the Freeze Frame Data memorized when the DTC (C1377/43) is stored (see FREEZE FRAME DATA  ).

      Result 

      RESULT REFERENCE

      Condition Proceed to
      Information codes (109, and 110) are output A
      Information codes (101, 102, 105, 106, 107, and 108) are output B
      Information code (103) is output C

    B: REPLACE BRAKE CONTROL POWER SUPPLY  (See REMOVAL  )

    C:  Go to step  7

    A: Go to next step 

  2. INSPECT FUSE (ABS1 AND ABS MAIN1 FUSES) 
    1. Remove the ABS1 and ABS MAIN1 fuses from the engine room No. 1 relay block (junction block).
    2. Check the ABS1 and ABS MAIN1 fuses.

      Standard resistance: 

      Below 1 Ω 

    NG: REPLACE FUSE (ABS1 OR ABS MAIN1 FUSE) 

    OK: Go to next step 

  3. INSPECT BRAKE CONTROL POWER SUPPLY (+BC AND GND TERMINAL) 
    1. Disconnect the U27 power supply connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      U27-8 (+BC) - Body ground 10 to 14 V
    3. Measure the resistance according to the value(s) in the table below.
      Fig 1: Identifying U27 Power Supply Connector
      G05816366Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      U27-14 (GND) - Body ground Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC OR GND CIRCUIT) 

    OK: Go to next step 

  4. CHECK SKID CONTROL ECU (Dl CIRCUIT) 
    1. Disconnect the A13 and A15 ECU connectors.
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      A13-39 (DI1) - Body ground 10 to 14 V
      A15-38 (DI2) - Body ground 10 to 14 V
      3. Fig 2: Identifying A13 And A15 ECU Connectors
      G05816367Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (Dl CIRCUIT) 

    OK: Go to next step 

  5. INSPECT BRAKE CONTROL POWER SUPPLY (CTY+ AND OUT TERMINAL) 
    1. Measure the voltage according to the value(s) in the table below.

      HINT:

      Perform inspection while the brake is not operated.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      U27-1 (OUT1) - Body ground 10 to 14 V
      U27-2 (CTY+) - Body ground 10 to 14 V*
      U27-7 (OUT2) - Body ground 10 to 14 V
      HINT:
      *: for 5 seconds after the driver's door is opened.
      2. Fig 3: Identifying Brake Control Power Supply (CTY+ And OUT Terminal)
      G05816368Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK:  Go to step  9

    NG: Go to next step 

  6. CHECK WIRE HARNESS (SKID CONTROL ECU - BRAKE CONTROL POWER SUPPLY) 
    1. Disconnect the A13 and A15 ECU connectors.
    2. Disconnect the U27 power supply connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard resistance 

      STANDARD RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      A13-13 (CTY+) - U27-2 (CTY+) Below 1 Ω
      A13-21 (CBI1) - U27-1 (OUT1) Below 1 Ω
      A15-40 (CBI2) - U27-7 (OUT2) Below 1 Ω
      A13-13 (CTY+) - Body ground 10 kΩ or higher
      A13-21 (CBI1) - Body ground 10 kΩ or higher
      A15-40 (CBI2) - Body ground 10 kΩ or higher
      4. Fig 4: Identifying A13 And A15 ECU With U27 Power Supply Connectors
      G05816369Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK:  Go to step  9

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

  7. INSPECT BATTERY 
    1. Check the battery voltage.

      Standard voltage: 

      10 to 14 V 

    NG: INSPECT CHARGING SYSTEM  (See ON-VEHICLE INSPECTION )

    OK: Go to next step 

  8. INSPECT BRAKE CONTROL POWER SUPPLY (+BC TERMINAL) 
    1. Disconnect the U27 power supply connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard voltage 

      STANDARD VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      U27-8 (+BC) - Body ground 10 to 14 V
      3. Fig 5: Identifying Terminal (+BC) Of U27 Power Supply Connector
      G05816370Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC CIRCUIT) 

    OK: Go to next step 

  9. RECONFIRM DTC 
    1. Clear the DTC (see DTC CHECK/CLEAR  ).
    2. Turn the power switch ON (IG).
    3. Check if the same DTC is recorded (see DTC CHECK/CLEAR  ).

      HINT:

      Reinstall the sensors, connectors, etc. and restore the vehicle to its prior condition before rechecking for DTCs.

      Result 

      RESULT REFERENCE

      Condition Proceed to
      DTC (C1377/43) is not output A
      DTC (C1377/43) is output B

    B: REPLACE BRAKE CONTROL POWER SUPPLY  (See REMOVAL  )

    A: END 

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