Dtc C1251/51 Open In Pump Motor Circuit

Brake. Corolla. Zre142 Aze141
Brake Control Dynamic Control Systems. Corolla. Zre142 Aze141

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)

INSPECT SKID CONTROL ECU (GND2 TERMINAL)

RECONFIRM DTC

DTC C1251/51 Open in Pump Motor Circuit


DESCRIPTION


DTC Code
DTC Detection Condition
Trouble Area
C1251/51
Either of the following is detected:
  1. Actuator pump motor does not operate properly.
  2. Open in actuator pump motor circuit continues for at least 2 seconds.
  1. Brake actuator assembly (Ground circuit)
  2. Brake actuator assembly (Motor circuit)

WIRING DIAGRAM

Refer to DTCs C0273/13 and C0274/14 (Link).

INSPECTION PROCEDURE

1.PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)

  1. Connect the Techstream to the DLC3.

  1. Start the engine.

  1. Select Active Test mode on the Techstream (COROLLA_ZRE142 RM000000XHW0BZX.html).

    ABS/VSC/TRAC
    Tester Display
    		Test Part
    		Control Range
    		Diagnostic Note
    Motor Relay
    		ABS motor relay
    		Relay ON/OFF
    		Operating sound of motor can be heard

  1. Check the operating sound of the ABS motor relay when operating it with the Techstream.

    Result:

    Result
    		Proceed to
    The operating sound is not heard
    		A
    The operating sound is heard
    		B


B
Go to step 3
A


2.INSPECT SKID CONTROL ECU (GND2 TERMINAL)


    Corolla. Zre142 Aze141.Brake Control Dynamic Control Systems.Anti-Lock Brake System. Dtc C1251/51 Open In Pump Motor Circuit

  1. Turn the ignition switch off.

  1. Disconnect the skid control ECU connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A51-13 (GND2) - Body ground
    		Always
    		Below 1 Ω


NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (GND2 CIRCUIT)
OK


3.RECONFIRM DTC
HINT:
This code is detected when a problem is identified in the brake actuator assembly.
The ABS motor relay is in the brake actuator assembly.
Therefore, ABS motor relay inspection and motor relay unit inspection cannot be performed. Be sure to check if the DTC is output before replacing the brake actuator assembly.

  1. Turn the ignition switch off.

  1. Reconnect the skid control ECU connector.

  1. Clear the DTCs (COROLLA_ZRE142 RM000000XHV0F3X.html).

  1. Start the engine.

  1. Drive the vehicle at a speed of 20 km/h (12 mph) or more for 30 seconds or more.

  1. Check if the same DTC is recorded (COROLLA_ZRE142 RM000000XHV0F3X.html).

    Result:

    Result
    		Proceed to
    DTC (C1251/51) is not output
    		A
    DTC (C1251/51) is output
    		B
    HINT:
    1. If a speed signal of 6 km/h (4 mph) or more is input to the skid control ECU, with the ignition switch ON and the stop light switch off, the ECU performs self diagnosis of the motor and solenoid circuits.
    2. If the normal system code is output (no trouble codes are output), slightly jiggle the connectors, wire harness, and fuses of the brake actuator assembly. Make sure that no DTCs are output.
    3. If any DTCs are output while jiggling a connector or wire harness of the brake actuator assembly (skid control ECU), inspect and repair the connector or wire harness.
    4. It is suspected that the DTCs were output due to a bad connection of the connector terminal.


B
REPLACE BRAKE ACTUATOR ASSEMBLY (COROLLA_ZRE142 RM0000013P6022X.html)
A

CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (COROLLA_ZRE142 RM000000XHP0ELX.html)