ELECTRONICALLY CONTROLLED BRAKE SYSTEM(w/o Vacuum Brake Booster), Diagnostic DTC:C1377

DTC Code DTC Name
C1377 Capacitor Malfunction

DESCRIPTION

The brake control power supply with bracket assembly is used as auxiliary power for brake control when the 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 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 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 battery (12 V) and brake control power supply with bracket assembly output 1 (OUT1).

      3. Open or short circuit between 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

 -
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
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
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 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
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
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
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
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 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
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 battery (12 V) and brake control power supply with bracket assembly output 1 (OUT1) - ○ - - -
Short circuit between battery (12 V) and brake control power supply with bracket assembly output 1 (OUT1) - - ○ - -
Open between battery (12 V) and brake control power supply with bracket assembly output 2 (OUT2) - - - ○ -
Short circuit between 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

WIRING DIAGRAM

B006CMJE14

CAUTION / NOTICE / HINT

Note


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

    Click here

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

PROCEDURE


  1. CHECK FREEZE FRAME DATA


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

      Click here


      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

    B

    REPLACE BRAKE CONTROL POWER SUPPLY WITH BRACKET ASSEMBLY Click here

    C

    CHECK BATTERY Click here

    A

  2. 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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC CIRCUIT)

    OK

  3. 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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

    OK

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


    1. B006E01C08
      *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 engine switch on (IG).

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

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

    NG

    REPLACE BRAKE CONTROL POWER SUPPLY WITH BRACKET ASSEMBLY Click here

    OK

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


    1. B006DUUC31
      *a

      Component with harness connected

      (Skid Control ECU Assembly)

      Turn the engine switch on (IG).

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

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

    NG

    REPLACE SKID CONTROL ECU ASSEMBLY Click here

    OK

  6. RECONFIRM DTC


    1. Turn the engine switch off.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the engine switch off.

    4. Turn the engine switch on (IG).

    5. Check if the same DTC is output.

      Click here


      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 CHECK Click here

    B

    REPLACE SKID CONTROL ECU ASSEMBLY Click here

  7. CHECK BATTERY


    1. Check the battery voltage.

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      Battery Engine switch off 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHARGE OR REPLACE BATTERY

    OK

  8. 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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC CIRCUIT)

    OK

  9. 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 ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)