Lexus ES manuals

Lexus ES: Power Supply Drive Circuit (C1257)

Lexus ES (XZ10) Service Manual / Brake / Brake Control / Dynamic Control Systems / Electronically Controlled Brake System (for Hv Model) / Power Supply Drive Circuit (C1257)

DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) detects a drop in accumulator pressure according to the signals from the accumulator pressure sensor, then operates and stops the motor relay as well as the pump motor.

The skid control ECU (brake booster with master cylinder assembly) troubleshoots the built-in motor relay drive circuit, and stores this DTC when a malfunction is detected.

DTC No.

Detection Item

INF Code

DTC Detection Condition

Trouble Area

MIL

Note

C1257

Power Supply Drive Circuit

361

362
  • INF Code: 361
    • After hard pump motor operation, when the accumulator pressure is less than 15.3 MPa (156 kgf/cm2, 2219 psi), the pump motor does not operate for 1 second or more.
  • INF Code: 362
    • When a motor relay drive test is being performed, one or both motor relays do not operate for 0.2 seconds or more.

Skid control ECU (brake booster with master cylinder assembly)

Does not come on

Electronically controlled brake system DTC

CAUTION / NOTICE / HINT

NOTICE:

After replacing the skid control ECU (brake booster with master cylinder assembly), perform linear solenoid valve offset learning, ABS holding solenoid valve learning, yaw rate and acceleration sensor zero point calibration and system information memorization after performing "Reset Memory".

Click here

PROCEDURE

1.

CHECK DTC

(a) Clear the DTCs.

Click here

Chassis > ABS/VSC/TRAC > Clear DTCs

(b) Turn the power switch off.

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

(d) Check if the same DTC is output.

Click here

Chassis > ABS/VSC/TRAC > Trouble Codes

Result

Proceed to

DTC C1257 is output.

A

DTCs C1241, C1242 and/or C1253 are output.

B
A

REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY

B

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

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