DTC C1391: Abnormal Leak in Accumulator [02/2019 - 12/2021]: Description

This DTC is stored if internal or external brake fluid leaks are detected due to improper sealing in the brake actuator (brake booster with master cylinder assembly) or brake booster pump assembly. Internal leaks are suspected if the pump motor operates frequently without braking.

DTC No.	Detection Item	INF Code	DTC Detection Condition	Trouble Area	Note
C1391	Abnormal Leak in Accumulator	351	Either of the following is detected: Accumulator pressure sensor input does not increase before braking or while the pump motor is operating. Accumulator pressure sensor input reduction rate exceeds the specification before braking and while the pump motor is not operating.	Brake fluid leaks Brake actuator (Brake booster with master cylinder assembly) (Malfunctioning internal seal, low gas pressure in accumulator, etc.)	-

DTC DETECTION CONDITIONS: C1391

		Vehicle Condition
		Pattern 1	Pattern 2
Diagnosis Condition	-	-	-
Malfunction Status	Accumulator pressure sensor input does not increase before braking or while the pump motor is operating	◦	-
Malfunction Status	Accumulator pressure sensor input reduction rate exceeds the specification before braking and while the pump motor is not operating	-	◦
Detection Time		-	-
Number of Trips		1 trip	1 trip

HINT:

DTC will be output when conditions for either of the patterns in the table above are met.