DTC C1378/44 Capacitor Communication Malfunction: Description

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

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

DTC DETECTION CONDITION CHART

DTC No.	INF Code	DTC Detection Condition	Trouble Area
C1378/44	112	When either condition below is met: Open or short in FAIL line Malfunction inside the power back up unit	Harness and connector Skid control ECU
C1377/43	113	When either condition below is met: Open or short in ENA line Malfunction inside the skid control ECU (circuit for communication with the capacitor)	Harness and connector Skid control ECU