DTC C1252/52: Brake Booster Pump Motor on Time Abnormally Long; DTC C1253/53: Pump Motor Relay Malfunction [03/2017 - 09/2018]: Description

The skid control ECU assembly detects decreases in the accumulator pressure according to the data from the accumulator pressure sensor, and then starts and stops the pump motor by operating the ABS motor relay.

The skid control ECU assembly usually drives the ABS motor relay 1 for electronically controlled brake system control, and the ABS motor relay 2 for ABS control. If either of them is malfunctioning, the other will substitute.

DTC No.	Detection Item	INF Code	DTC Detection Condition	Trouble Area	Note
C1252/52	Brake Booster Pump Motor on Time Abnormally Long	130	ABS motor relay is on for at least 3 minutes.	Short in pump motor circuit or pump motor monitor circuit ABS motor relay stuck Accumulator pressure sensor malfunction in brake actuator assembly Brake fluid leaks Brake booster pump assembly is deteriorated	Electronically controlled brake system DTC
C1253/53	Pump Motor Relay Malfunction	134 138 140	INF Code: 134 MTT input is less than 3.5 V for at least 1 second or more when linear solenoid power source voltage 1 is 9.5 V or more, either of +BI1 or +BI2 voltage is 7 V or more, and ABS motor relay 1 is on. INF Code: 138 MTT input is less than 3.5 V for at least 1 second or more when linear solenoid power source voltage 2 is 9.5 V or more, either of +BI1 or +BI2 voltage is 7 V or more, and ABS motor relay 2 is on. INF Code: 140 MTT input is 3.5 V or more for at least 2 seconds when ABS motor relay 1 and 2 are off.	INF Code: 134 Improperly connected connector, deformation or corrosion of terminals Open in ABS motor relay 1 internal circuit Open or short in ABS motor relay 1 circuit Open in pump motor circuit or pump motor monitor circuit INF Code: 138 Improperly connected connector, deformation or corrosion of terminals Open in ABS motor relay 2 internal circuit Open or short in ABS motor relay 1 circuit Open in pump motor circuit or pump motor monitor circuit INF Code: 140 Short in ABS motor relay 1 circuit and ABS motor relay 2 circuit Short in pump motor circuit or pump motor monitor circuit	Electronically controlled brake system DTC

DTC No.	Brake warning light / yellow (minor malfunction) code	ABS warning light code	Slip indicator light code	Brake hold standby indicator light code
C1252	52	42	45	21
C1253	53	42	45	21