DTC    C1377/43    Capacitor Malfunction

for Preparation Click here


DESCRIPTION

The brake control power supply assembly (capacitor) is used as auxiliary power for brake control when battery voltage is low.

DTC No.
INF Code
DTC Detection Condition
Trouble Area
C1377/43
101
Brake control power supply assembly is deteriorated (indicates a need to replace).
Brake control power supply
↑
102
Self-discharge (current leak) is excessive (internal malfunction).
↑
↑
103
Overvoltage (16.4 V or more) continues to be applied from the battery to the brake control power supply voltage input (+BC) for 10 seconds or more.
Apply high voltage
↑
105
Circuit inside the power back up unit (charge) is malfunctioning.
Brake control power supply
↑
106
Circuit inside the power back up unit (back up output circuit) is malfunctioning.
↑
↑
107
Malfunction in the forced discharge circuit.
↑
↑
108
Circuit inside the power back up unit (voltage monitor circuit) is malfunctioning.
↑
↑
109
Open circuit between battery (12 V) and brake control power supply power input (+BC terminal).
  1. ABS1 fuse
  2. ABS MAIN1 fuse
  3. Wire harness or connector
↑
110
When either of the following is detected:
  1. Open or short circuit between battery (12 V) and brake control power supply output 1 (OUT1).
  2. Open or short circuit between battery (12 V) and brake control power supply output 2 (OUT2).
  1. ABS1 fuse
  2. ABS MAIN1 fuse
  3. Wire harness or connector

WIRING DIAGRAM


C109410E01


INSPECTION PROCEDURE

1.CHECK FREEZE FRAME DATA

  1. Check the INF code from the FREEZE FRAME DATA memorized when the DTC (C1377/43) is stored (Click here).

    Result:

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



B
REPLACE BRAKE CONTROL POWER SUPPLY

C
Go to step 7
A


2.INSPECT FUSE (ABS1 AND ABS MAIN1 FUSES)

  1. Remove the ABS1 and ABS MAIN1 fuses from the engine room R/B (J/B) No.1.

  1. Check the ABS1 and ABS MAIN1 fuses.

    Resistance:
    Below 1 Ω (Continuity)



NG
REPLACE FUSE (ABS1 OR ABS MAIN1 FUSE)
OK


3.INSPECT BRAKE CONTROL POWER SUPPLY (+BC AND GND TERMINAL)


    C106625E04

  1. Disconnect the brake control power supply connector.

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

    Voltage:
    Tester Connection
    		Specified Condition
    V27-8 (+BC) - Body ground
    		10 to 14 V

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

    Resistance:
    Tester Connection
    		Specified Condition
    V27-14 (GND) - Body ground
    		Below 1 Ω



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


4.INSPECT SKID CONTROL ECU (DI TERMINAL)


    C110724E10

  1. Disconnect the skid control ECU (A13, A15) connectors.

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

    Voltage:
    Tester Connection
    		Specified Condition
    A13-39 (DI1) - Body ground
    		10 to 14 V
    A15-33 (DI2) - Body ground
    		10 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (DI CIRCUIT)
OK


5.INSPECT BRAKE CONTROL POWER SUPPLY (CTY+ AND OUT TERMINAL)


    C106626E02

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

    HINT:
    Perform inspection while the brake is not operated.

    Voltage:
    Tester Connection
    		Specified Condition
    V27-1 (OUT1) - Body ground
    		10 to 14 V
    V27-2 (CTY+) - Body ground
    		10 to 14 V (*1)
    V27-7 (OUT2) - Body ground
    		10 to 14 V

    (*1): For 5 seconds after the driver's door is opened.



OK
Go to step 9
NG


6.CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU TO BRAKE CONTROL POWER SUPPLY)


    C110906E02

  1. Disconnect the skid control ECU (A13, A15) connectors and brake control power supply connector.

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

    Resistance:
    Tester Connection
    		Specified Condition
    A13-13 (CTY+) - V27-2 (CTY+)
    		Below 1 Ω
    A13-21 (CBI1) - V27-1 (OUT1)
    		Below 1 Ω
    A15-35 (CBI2) - V27-7 (OUT2)
    		Below 1 Ω

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

    Resistance:
    Tester Connection
    		Specified Condition
    A13-13 (CTY+) - Body ground
    		10 kΩ or higher
    A13-21 (CBI1) - Body ground
    		10 kΩ or higher
    A15-35 (CBI2) - Body ground
    		10 kΩ or higher



OK
Go to step 9
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR 

7.INSPECT BATTERY

  1. Check the battery voltage.

    Voltage:
    11 to 14 V



NG
INSPECT CHARGING SYSTEM
OK


8.INSPECT BRAKE CONTROL POWER SUPPLY (+BC TERMINAL)


    C106625E05

  1. Disconnect the brake control power supply connector.

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

    Voltage:
    Tester Connection
    		Specified Condition
    V27-8 (+BC) - Body ground
    		10 to 14 V



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


9.RECONFIRM DTC

  1. Clear the DTC (Click here).

  1. Turn the engine switch on (IG).

  1. Check if the same DTC is recorded (Click here).

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


    Result:

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



B
REPLACE BRAKE CONTROL POWER SUPPLY
A

END