C1377
C1377Description
The brake capacitor is used as auxiliary power for brake control when battery voltage is low.
C1377:
Diagnosis Procedure
CAUTION:
When replacing the brake ECU, perform initialization of linear solenoid valve and calibration.
1.CHECK FREEZE FRAME DATA
Check the INF cord from the Freeze Frame Data memorized when the DTC (C1377) is stored.
Result:
A >> GO TO 2.
B >> Replace brake capacitor.
C >> GO TO 9.
2.INSPECT ABS MAIN NO.3 FUSE
1. Remove the ABS No.2 fuse from the engine room R/B.
2. Measure the resistance according to the value(s) in the table below.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Replace ABS No.2 fuse.
3.INSPECT BRAKE CAPACITOR (+BC TERMINAL)
1. Install the ABS No.2 fuse.
2. Disconnect the brake capacitor connector.
3. Measure the voltage according to the value(s) in the table below.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace harness or connector (+BC circuit).
4.INSPECT BRAKE CAPACITOR (GND TERMINAL)
Measure the resistance according to the value(s) in the table below.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace harness or connector (GND circuit).
5.INSPECT BRAKE ECU (+DI TERMINAL)
1. Disconnect the brake ECU connectors.
2. Measure the voltage according to the value(s) in the table below.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair or replace harness or connector (+DI circuit).
6.INSPECT BRAKE CAPACITOR (OUT AND CTY+ TERMINAL)
1. Reconnect the brake capacitor connector.
2. Turn the ignition switch ON.
3. Measure the voltage according to the value(s) in the table below.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair or replace harness or connector (OUT or CTY+ circuit).
7.RECONFIRM DTC
1. Turn the ignition switch OFF.
2. Clear the DTC.
3. Turn the ignition switch ON.
4. Check if the same DTC is recorded.
Result:
A >> Check for intermittent problems (symptom simulation).
B >> Replace brake ECU.
8.CHECK AUXILIARY BATTERY
Check the auxiliary battery voltage.
Standard voltage: 11 to 14 V
Is the inspection result normal?
YES >> GO TO 9.
NO >> Charge or replace auxiliary battery.
9.INSPECT BRAKE CAPACITOR (+BC TERMINAL)
1. Disconnect the brake capacitor connector.
2. Measure the voltage according to the value(s) in the table below.
Is the inspection result normal?
YES >> GO TO 10.
NO >> Repair or replace harness or connector (+BC circuit).
10.RECONFIRM DTC
1. Clear the DTC.
2. Turn the ignition switch ON.
3. Check if the same DTC is recorded.
Result:
A >> Check for intermittent problems (symptom simulation).
B >> Replace brake capacitor.
Special Repair Requirement
1.ZERO ADJUSTMENT FOR EACH SENSOR AND OFFSET LEANING FOR LINEAR SOLENOID VALVE
After erasing brake ECU memories, perform zero adjustment of following sensors and initialization of linear solenoid valve.
^ Steering angle sensor: BRC-9, "PERFORM ZERO POINT OF STEERING ANGLE SENSOR: Description". Testing and Inspection
^ Yaw rate/side/decel G sensor: BRC-8, "PERFORM ZERO POINT OF YAW RATE/SIDE/DECEL G SENSOR: Description". Testing and Inspection
^ Brake stroke sensor: BRC-9, "PERFORM ADJUSTMENT OF STROKE SENSOR: Description". Perform Adjustment of Stroke Sensor
^ Linear solenoid valve: BRC-7, "PERFORM INITIALIZATION OF LINEAR SOLENOID VALVE AND CALIBRATION: Description". Perform Initialization of Linear Solenoid Valve and Calibration
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