ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1257/57

DTC Code DTC Name
C1257/57 Power Supply Drive Circuit

DESCRIPTION

The skid control ECU 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 troubleshoots the built-in motor relay drive circuit, and outputs this DTC when a malfunction is detected.

DTC Code INF Code DTC Detection Condition Trouble Area
C1257/57 361 While accumulator pressure falls below hard pump ON pressure, the hard drive circuit does not operate for 1 second or more. Brake booster with master cylinder (Skid control ECU)
↑ 362 When hard driving, one of the 3 built-in motor relays does not operate for 0.2 seconds or more. ↑

CAUTION / NOTICE / HINT

Note

When replacing the brake booster with master cylinder (skid control ECU), perform initialization and calibration of the linear solenoid valve Click here.

Tech Tips

When C1241/41, C1242/42 and/or C1253/53 are output together with C1257/57, inspect and repair the trouble areas indicated by C1241/41, C1242/42 and/or C1253/53 first (See page or Click here).

PROCEDURE


  1. REPLACE BRAKE BOOSTER WITH MASTER CYLINDER


    1. Replace the brake booster with master cylinder (skid control ECU) (See page for LHD or Click here for RHD).


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