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ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1377

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DTC Code DTC Name
C1377 Capacitor Malfunction
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DESCRIPTION

The brake control power supply with bracket assembly is used as auxiliary power for brake control when the auxiliary battery voltage is low.

DTC No. Detection Item INF Code DTC Detection Condition Trouble Area Note
C1377 Capacitor Malfunction

101

102

103

105

106

108

109

110

  • INF Code: 101


    • Either of the following is detected:


      1. IG1 terminal voltage is 9.5 V or more, and malfunction signal (not brake control power supply with bracket assembly communication malfunction) reception condition continues for 3 seconds or more.

      2. Brake control power supply with bracket assembly is deteriorated (replacement necessary).

  • INF Code: 102


    • Either of the following is detected:


      1. IG1 terminal voltage is 9.5 V or more, and malfunction signal (not brake control power supply with bracket assembly communication malfunction) reception condition continues for 3 seconds or more.

      2. Self discharge (current leak) is excessive (internal malfunction).

  • INF Code: 103


    • Either of the following is detected:


      1. IG1 terminal voltage is 9.5 V or more, and malfunction signal (not brake control power supply with bracket assembly communication malfunction) reception condition continues for 3 seconds or more.

      2. Overvoltage (16.4 V or more) continues to be applied from the auxiliary battery to the brake control power supply with bracket assembly voltage input (+BC) for 10 seconds or more.

  • INF Code: 105


    • Either of the following is detected:


      1. IG1 terminal voltage is 9.5 V or more, and malfunction signal (not brake control power supply with bracket assembly communication malfunction) reception condition continues for 3 seconds or more.

      2. Circuit inside the power back up unit (charge) is malfunctioning.

  • INF Code: 106


    • Either of the following is detected:


      1. IG1 terminal voltage is 9.5 V or more, and malfunction signal (not brake control power supply with bracket assembly communication malfunction) reception condition continues for 3 seconds or more.

      2. Circuit inside the power back up unit (back up output circuit) is malfunctioning.

  • INF Code: 108


    • Either of the following is detected:


      1. IG1 terminal voltage is 9.5 V or more, and malfunction signal (not brake control power supply with bracket assembly communication malfunction) reception condition continues for 3 seconds or more.

      2. Circuit inside the power back up unit (voltage monitor circuit) is malfunctioning.

  • INF Code: 109


    • Either of the following is detected:


      1. IG1 terminal voltage is 9.5 V or more, and malfunction signal (not brake control power supply with bracket assembly communication malfunction) reception condition continues for 3 seconds or more.

      2. Open circuit between auxiliary battery (12 V) and brake control power supply with bracket assembly power input (+BC terminal).

  • INF Code: 110


    • Either of the following is detected:


      1. IG1 terminal voltage is 9.5 V or more, and malfunction signal (not brake control power supply with bracket assembly communication malfunction) reception condition continues for 3 seconds or more.

      2. Open or short circuit between auxiliary battery (12 V) and brake control power supply with bracket assembly output 1 (OUT1).

      3. Open or short circuit between auxiliary battery (12 V) and brake control power supply with bracket assembly output 2 (OUT2).

  • INF Code: 101, 102, 105, 106, 108


    • Brake control power supply with bracket assembly

  • INF Code: 103


    • Apply high voltage

  • INF Code: 109


    • CAPACITOR fuse

    • Wire harness and connector

    • Improperly connected connector, deformation or corrosion of terminals

  • INF Code: 110


    • Wire harness and connector

    • Improperly connected connector, deformation or corrosion of terminals

 -
Table 1. DTC Detection Conditions: C1377 INF Code: 101
  Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition IG1 terminal voltage is 9.5 V or more ○ -
Malfunction Status A malfunction signal (not communication malfunction) is received from the brake control power supply with bracket assembly ○ -
Brake control power supply with bracket assembly is deteriorated (replacement necessary). - ○
Detection Time 3 seconds or more -
Number of Trips 1 trip 1 trip
Table 2. DTC Detection Conditions: C1377 INF Code: 102
  Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition IG1 terminal voltage is 9.5 V or more ○ -
Malfunction Status A malfunction signal (not communication malfunction) is received from the brake control power supply with bracket assembly ○ -
Self discharge (current leak) is excessive (internal malfunction). - ○
Detection Time 3 seconds or more -
Number of Trips 1 trip 1 trip
Table 3. DTC Detection Conditions: C1377 INF Code: 103
  Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition IG1 terminal voltage is 9.5 V or more ○ -
Malfunction Status A malfunction signal (not communication malfunction) is received from the brake control power supply with bracket assembly ○ -
Overvoltage (16.4 V or more) continues to be applied from the auxiliary battery to the brake control power supply with bracket assembly voltage input (+BC) for 10 seconds or more. - ○
Detection Time 3 seconds or more -
Number of Trips 1 trip 1 trip
Table 4. DTC Detection Conditions: C1377 INF Code: 105
  Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition IG1 terminal voltage is 9.5 V or more ○ -
Malfunction Status A malfunction signal (not communication malfunction) is received from the brake control power supply with bracket assembly ○ -
Circuit inside the power back up unit (charge) is malfunctioning. - ○
Detection Time 3 seconds or more -
Number of Trips 1 trip 1 trip
Table 5. DTC Detection Conditions: C1377 INF Code: 106
  Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition IG1 terminal voltage is 9.5 V or more ○ -
Malfunction Status A malfunction signal (not communication malfunction) is received from the brake control power supply with bracket assembly ○ -
Circuit inside the power back up unit (back up output circuit) is malfunctioning. - ○
Detection Time 3 seconds or more -
Number of Trips 1 trip 1 trip
Table 6. DTC Detection Conditions: C1377 INF Code: 108
  Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition IG1 terminal voltage is 9.5 V or more ○ -
Malfunction Status A malfunction signal (not communication malfunction) is received from the brake control power supply with bracket assembly ○ -
Circuit inside the power back up unit (voltage monitor circuit) is malfunctioning. - ○
Detection Time 3 seconds or more -
Number of Trips 1 trip 1 trip
Table 7. DTC Detection Conditions: C1377 INF Code: 109
  Vehicle Condition
Pattern 1 Pattern 2
Diagnosis Condition IG1 terminal voltage is 9.5 V or more ○ -
Malfunction Status A malfunction signal (not communication malfunction) is received from the brake control power supply with bracket assembly ○ -
Open circuit between auxiliary battery (12 V) and brake control power supply with bracket assembly power input (+BC terminal). - ○
Detection Time 3 seconds or more -
Number of Trips 1 trip 1 trip
Table 8. DTC Detection Conditions: C1377 INF Code: 110
  Vehicle Condition
Pattern 1 Pattern 2 Pattern 3 Pattern 4 Pattern 5
Diagnosis Condition IG1 terminal voltage is 9.5 V or more ○ - - - -
Malfunction Status A malfunction signal (not communication malfunction) is received from the brake control power supply with bracket assembly ○ - - - -
Open between auxiliary battery (12 V) and brake control power supply with bracket assembly output 1 (OUT1) - ○ - - -
Short circuit between auxiliary battery (12 V) and brake control power supply with bracket assembly output 1 (OUT1) - - ○ - -
Open between auxiliary battery (12 V) and brake control power supply with bracket assembly output 2 (OUT2) - - - ○ -
Short circuit between auxiliary battery (12 V) and brake control power supply with bracket assembly output 2 (OUT2) - - - - ○
Detection Time 3 seconds or more - - - -
Number of Trips 1 trip 1 trip 1 trip 1 trip 1 trip
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WIRING DIAGRAM

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CAUTION / NOTICE / HINT

Note:

  • When replacing the skid control ECU assembly, perform initialization and calibration of the linear solenoid valve.

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  • Inspect the fuses for circuits related to this system before performing the following procedure.

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PROCEDURE


  1. Click here

    CHECK FREEZE FRAME DATA


    1. Check the INF code from the Freeze Frame Data stored when DTC (C1377) was stored.

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      1. Chassis > ABS/VSC/TRC > DTC(C1377) > Freeze Frame Data
        Tester Display
        Detailed Freeze DTC




      Result
      Result Proceed to
      INF codes 109 and/or 110 are output. A
      INF codes 101, 102, 105, 106 and/or 108 are output. B
      INF code 103 is output. C

  2. Click here

    CHECK HARNESS AND CONNECTOR (+BC TERMINAL)


    1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    2. Disconnect the L101 brake control power supply with bracket assembly connector.

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      L101-5 (+BC) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC CIRCUIT)

  3. Click here

    CHECK HARNESS AND CONNECTOR (GND TERMINAL)


    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      L101-8 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

  4. Click here

    INSPECT BRAKE CONTROL POWER SUPPLY WITH BRACKET ASSEMBLY (BRAKE CONTROL POWER SUPPLY WITH BRACKET ASSEMBLY POWER SUPPLY OUTPUT)


    1. B004RB6C08
      *a

      Component with harness connected

      (Brake Control Power Supply with Bracket Assembly)

      Reconnect the L101 brake control power supply with bracket assembly connector.

    2. Turn the power switch on (IG).

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      L101-1 (OUT1) - Body ground Power switch on (IG) 11 to 14 V
      L101-4 (OUT2) - Body ground Power switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

  5. Click here

    INSPECT SKID CONTROL ECU ASSEMBLY (BRAKE CONTROL POWER SUPPLY WITH BRACKET ASSEMBLY POWER SUPPLY INPUT)


    1. B004YC8C31
      *a

      Component with harness connected

      (Skid Control ECU Assembly)

      Turn the power switch on (IG).

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      A11-7 (CBI1) - Body ground Power switch on (IG) 8.8 to 14 V
      A12-2 (CBI2) - Body ground Power switch on (IG) 8.8 to 14 V
      Result
      Proceed to
      OK
      NG

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    RECONFIRM DTC


    1. Turn the power switch off.

    2. Clear the DTCs.

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      1. Chassis > ABS/VSC/TRC > Clear DTCs


    3. Turn the power switch off.

    4. Turn the power switch on (IG).

    5. Check if the same DTC is output.

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      1. Chassis > ABS/VSC/TRC > Trouble Codes


      Result
      Result Proceed to
      DTC C1377 is not output. A
      DTC C1377 is output. B

    • A

      USE SIMULATION METHOD TO CHECKClick here

    • B

      REPLACE SKID CONTROL ECU ASSEMBLY for LHD:Click here

      REPLACE SKID CONTROL ECU ASSEMBLY for RHD:Click here

  7. Click here

    CHECK AUXILIARY BATTERY


    1. Check the auxiliary battery voltage.

      Standard Voltage
      Tester Connection Condition Specified Condition
      Auxiliary battery Power switch on (IG) 11 to 14 V
      Auxiliary battery Power switch on (READY) 11 to 15.5 V
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      CHARGE OR REPLACE AUXILIARY BATTERY

  8. Click here

    CHECK HARNESS AND CONNECTOR (+BC TERMINAL)


    1. Make sure that there is no looseness at the locking part and the connecting part of the connector.

    2. Disconnect the L101 brake control power supply with bracket assembly connector.

    3. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      L101-5 (+BC) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    • OKClick here
    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC CIRCUIT)

  9. Click here

    CHECK HARNESS AND CONNECTOR (GND TERMINAL)


    1. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      L101-8 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    • OK

      REPLACE BRAKE CONTROL POWER SUPPLY WITH BRACKET ASSEMBLYClick here

    • NG

      REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)