C1377

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

DESCRIPTION

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

WIRING DIAGRAM

INSPECTION PROCEDURE

PROCEDURE

1. CHECK FREEZE FRAME DATA

(a) Check the information code from the Freeze Frame Data memorized when the DTC (C1377/43) is stored Freeze Frame Data.

Result:

C -- INSPECT BATTERY

B -- REPLACE BRAKE CONTROL POWER SUPPLY
A -- Continue to next step.

2. INSPECT FUSE (ABS1 AND ABS MAIN1 FUSES)

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

(b) Check the ABS1 and ABS MAIN1 fuses.

Resistance:

Below 1 Ohms (Continuity)

NG -- REPLACE FUSE (ABS1 OR ABS MAIN1 FUSE)
OK -- Continue to next step.

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

(a) Disconnect the brake control power supply connector.

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

Voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC OR GND CIRCUIT)
OK -- Continue to next step.

4. INSPECT SKID CONTROL ECU (DI TERMINAL)

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

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

Voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (DI CIRCUIT)
OK -- Continue to next step.

5. INSPECT BRAKE CONTROL POWER SUPPLY (OUT TERMINAL)

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

HINT
Perform inspection while the brake is not operated.

Voltage:

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

OK -- RECONFIRM DTC
NG -- Continue to next step.

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

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

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

Resistance:

OK -- RECONFIRM DTC

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR

7. INSPECT BATTERY

(a) Check the battery voltage.

Voltage:

11 to 14 V

NG -- INSPECT CHARGING SYSTEM
OK -- Continue to next step.

8. 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.

Voltage:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (+BC CIRCUIT)
OK -- Continue to next step.

9. RECONFIRM DTC

(a) Clear the DTC Electronically Controlled Brake System.

(b) Turn the engine switch on (IG).

(c) Check if the same DTC is recorded Electronically Controlled Brake System.

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

Result:

B -- REPLACE BRAKE CONTROL POWER SUPPLY

A -- END