C1377

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1377/43: Capacitor Malfunction

DTC C1377/43 - Capacitor Malfunction

DESCRIPTION

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






WIRING DIAGRAM














INSPECTION PROCEDURE
NOTICE: When replacing the skid control ECU, perform initialization of linear solenoid valve and calibration Initialization.

PROCEDURE

1. CHECK FREEZE FRAME DATA
(a) Check the INF code from the Freeze Frame Data memorized when the DTC (C1377/43) is stored Freeze Frame Data.
Result:






C -- CHECK AUXILIARY BATTERY
B -- REPLACE BRAKE CONTROL POWER SUPPLY (CAPACITOR)
A -- Continue to next step.
2. INSPECT ABS MAIN NO. 3 FUSE




(a) Remove the ABS MAIN NO. 3 fuse from the engine room R/B.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPLACE ABS MAIN NO. 3 FUSE
OK -- Continue to next step.
3. INSPECT BRAKE CONTROL POWER SUPPLY (+BC TERMINAL)




(a) Install the ABS MAIN NO. 3 fuse.
(b) Disconnect the brake control power supply connector.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC CIRCUIT)
OK -- Continue to next step.
4. INSPECT BRAKE CONTROL POWER SUPPLY (GND TERMINAL)




(a) Measure the resistance according to the value(s) in the table below.
Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)
OK -- Continue to next step.
5. INSPECT SKID CONTROL ECU (+BI TERMINAL)




(a) Disconnect the skid control ECU connectors.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (+BI CIRCUIT)
OK -- Continue to next step.
6. INSPECT SKID CONTROL ECU (RELAY INPUT)




(a) Reconnect the skid control ECU connectors.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPLACE SKID CONTROL ECU
OK -- Continue to next step.
7. INSPECT BRAKE CONTROL POWER SUPPLY (OUT AND CTY+ TERMINAL)




(a) Reconnect the brake control power supply connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
HINT: Perform inspection while the brake is not operated.

Standard voltage:





(*1): For 5 seconds after the driver's door is opened.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (OUT OR CTY+ CIRCUIT)
OK -- Continue to next step.
8. RECONFIRM DTC
(a) Turn the power switch off.
(b) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(c) Turn the power switch on (IG).
(d) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.
Result:






B -- REPLACE SKID CONTROL ECU
A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)
9. CHECK AUXILIARY BATTERY
(a) Check the auxiliary battery voltage.
Standard voltage:
11 to 14 V
NG -- CHARGE OR REPLACE AUXILIARY BATTERY
OK -- Continue to next step.
10. INSPECT BRAKE CONTROL POWER SUPPLY (+BC TERMINAL)




(a) Disconnect the brake control power supply connector.
(b) Measure the voltage according to the value(s) in the table below.
Standard voltage:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC CIRCUIT)
OK -- Continue to next step.
11. RECONFIRM DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Turn the power switch on (IG).
(c) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.
Result:






B -- REPLACE BRAKE CONTROL POWER SUPPLY (CAPACITOR)
A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)