DTC    C1377/43    Capacitor Malfunction

for Preparation Click here


DESCRIPTION

The brake control power supply assembly (capacitor) provides auxiliary power for brake control when an auxiliary battery (12 V) voltage drops.

DTC No.
INF Code
DTC Detecting Condition
Trouble Area
C1377/43
101
Brake control power supply assembly is deteriorated (indicates a need to replace).
  1. Brake control power supply
C1377/43
102
Self-discharge (current leak) is excessive (internal malfunction).
  1. Brake control power supply
C1377/43
103
Input voltage from the auxiliary battery (12 V) to the brake control power supply is 16.4 V or more for at least 10 sec.
  1. Apply high voltage
C1377/43
105
Circuit inside the power back up unit (charge) is malfunctioning.
  1. Brake control power supply
C1377/43
106
Circuit inside the power back up unit (back up output circuit) is malfunctioning.
  1. Brake control power supply
C1377/43
108
Circuit inside the power back up unit (voltage monitor circuit) is malfunctioning.
  1. Brake control power supply
C1377/43
109
Open circuit between auxiliary battery (12 V) and brake control power supply power input (+BC terminal).
  1. Harness and connector
  2. ABS No.3 fuse
C1377/43
110
  1. Open or short circuit between auxiliary battery (12 V) and brake control power supply output 1 (OUT 1).
  2. Open or short circuit between auxiliary battery (12 V) and brake control power supply output 2 (OUT 2)
  1. Harness and connector
  2. ABS No.1 fuse
  3. ABS No.2 fuse

WIRING DIAGRAM

Refer to DTCs C1241/41 and C1242/42 (Click here).

INSPECTION PROCEDURE

NOTICE:
When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration (Click here).

1.CHECK FREEZE FRAME DATA

  1. Check the INF code from the FREEZE FRAME DATA memorized when the DTC (C1337/43) is stored (Click here).

    Result:

    Condition
    		Proceed To
    INF codes (109 and 110) are output
    		A
    INF codes (101, 102, 105, 106 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 (ABS NO.3 FUSE)


    C114605E01

  1. Remove the ABS No.3 fuse from the engine room R/B No.4.

  1. Check the ABS No.3 fuse.

    Resistance:
    Below 1 Ω (Continuity)



NG
REPLACE FUSE
OK


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


    F100411E05

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

    HINT:
    Measure the voltage from the back side of the connector with the connector connected.

    Voltage:
    Tester Connection
    		Specified Condition
    B22-8 (+BC) - Body ground
    		10 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


4.INSPECT SKID CONTROL ECU (+BI1, +BI2 TERMINAL)


    F047485E31

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

    HINT:
    Measure the voltage from the back side of the connector with the connector connected to the skid control ECU.

    Voltage:
    Tester Connection
    		Specified Condition
    S40-3 (+BI1) - Body ground
    		10 to 14 V
    S39-5 (+BI2) - Body ground
    		10 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.INSPECT SKID CONTROL ECU (+BO1, +BO2 TERMINAL)


    F047485E32

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

    HINT:
    Measure the voltage from the back side of the connector with the connector connected to the skid control ECU.

    Voltage:
    Tester Connection
    		Specified Condition
    S40-5 (+BO1) - Body ground
    		10 to 14 V
    S39-4 (+BO2) - Body ground
    		10 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


6.INSPECT BRAKE CONTROL POWER SUPPLY (+BCTY, OUT1, OUT2 TERMINAL)


    F100411E06

  1. Turn the ignition switch on.

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

    HINT:
    Measure the voltage from the back side of the connector with the connector connected.

    Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    B22-1 (OUT1) - Body ground
    		Ignition switch ON
    		9 to 13 V
    B22-2 (CTY+) - Body ground
    		Ignition switch ON
    		9 to 13 V
    B22-7 (OUT2) - Body ground
    		Ignition switch ON
    		9 to 13 V



OK
REPLACE SKID CONTROL ECU
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR 

7.INSPECT BATTERY

  1. Check the battery voltage.

    Voltage:
    10 to 14 V



NG
INSPECT CHARGING SYSTEM
OK


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


    F100411E07

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

    HINT:
    Measure the voltage from the back side of the connector with the connector connected.

    Voltage:
    Tester Connection
    		Specified Condition
    B22-8 (+BC) - Body ground
    		9 to 13 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

REPLACE BRAKE CONTROL POWER SUPPLY