Up to 08/2009

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1378/44: Capacitor Communication Malfunction
C1378/44 - Capacitor Communication Malfunction

DESCRIPTION

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

The FAIL and ENA lines are placed between the skid control ECU and the brake control power supply.

Signals indicating that the brake control power supply is in auxiliary mode are sent to the skid control ECU through the FAIL line.

Charge permit prohibition signals are sent to the brake control power supply through the ENA line.





WIRING DIAGRAM





INSPECTION PROCEDURE

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

PROCEDURE

1. INSPECT BRAKE CONTROL POWER SUPPLY (IG1 TERMINAL)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.





(b) Disconnect the brake control power supply connector.

(c) Turn the power switch on (IG).

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

Standard Voltage:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)
OK -- Continue to next step.

2. INSPECT BRAKE CONTROL POWER SUPPLY (GND TERMINAL)

(a) Turn the power switch off.





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

Standard Resistance:





Text in Illustration





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

3. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - BRAKE CONTROL POWER SUPPLY)

(a) Make sure that there is no looseness at the locking part and the connecting part of the connector.





(b) Disconnect the skid control ECU connectors.

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

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

4. RECONFIRM DTC

(a) Reconnect the skid control ECU connectors and the brake control power supply connector.

(b) Clear the DTCs 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 -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting
A -- Continue to next step.

5. CHECK FREEZE FRAME DATA

(a) Check the INF code from the Freeze Frame Data memorized when the DTC (C1378/44) is stored Freeze Frame Data.

Result:





B -- REPLACE BRAKE CONTROL POWER SUPPLY

A -- REPLACE SKID CONTROL ECU Removal