DESCRIPTION

The motor relay (semiconductor relay) is built into the hydraulic brake booster and drives the pump motor based on a signal from the skid control ECU (master cylinder solenoid).

DTC No.

DTC Detecting Condition

Trouble Areas

C1257

Open in pump motor input circuit

Hydraulic brake booster pump motor circuit

PROCEDURE

1.

CHECK HYDRAULIC BRAKE BOOSTER PUMP MOTOR OPERATION

(a) Turn the ignition switch to OFF.

(b) Disconnect the actuator connector (S1).

(c) Depress the brake pedal more than 20 times.

(d) Turn the ignition switch to the ON position.

(e) Check the hydraulic brake booster pump motor operation.

OK:

Hydraulic brake booster pump operates.

NG

REPLACE MASTER CYLINDER SOLENOID

OK

2.

RECONFIRM DTC

(a) Turn the ignition switch to OFF.

(b) Reconnect the actuator connector (S1).

(c) Turn the ignition switch to the ON position.

(d) Clear the DTCs (See page ). (e) Check if the same DTCs are recorded. ).

(e) Check if the same DTCs are recorded.

Result

Proceed to

DTC output

A

DTC not output

B

A

REPLACE MASTER CYLINDER SOLENOID

B

END