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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.

      Result 

      RESULT

      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 

      TESTER CONNECTION SPECIFIED CONDITION

      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.

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      U27-14 (GND) - Body ground Below 1 Ω
      Fig 1: Identifying U27 Connector Terminals
      G05305996Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    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 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      A13-39 (DI1) - Body ground 10 to 14 V
      A15-38 (DI2) - Body ground 10 to 14 V
      Fig 2: Identifying A13 And A15 Connectors Terminals
      G05305985Courtesy 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 

      TESTER CONNECTION SPECIFIED CONDITION

      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.
      Fig 3: Identifying U27 Connector Terminals
      G05305998Courtesy 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 

      TESTER CONNECTION SPECIFIED CONDITION

      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
      Fig 4: Identifying A15, A13 And U27 Connectors Terminals
      G05305999Courtesy 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 

      TESTER CONNECTION SPECIFIED CONDITION

      Tester Connection Specified Condition
      U27-8 (+BC) - Body ground 10 to 14 V
      Fig 5: Identifying U27 Connector Terminals
      G05306000Courtesy 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

      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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