Dtc C0273 Open In Abs Motor Relay Circuit

Brake. Yaris. Ncp93, 131
Brake Control Dynamic Control Systems. Yaris. Ncp93, 131

DESCRIPTION

WIRING DIAGRAM

INSPECTION PROCEDURE

PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)

INSPECT SKID CONTROL ECU (BM TERMINAL)

INSPECT SKID CONTROL ECU (GND TERMINAL)

RECONFIRM DTC

DTC C0273 Open in ABS Motor Relay Circuit

DTC C0274 Short in ABS Motor Relay Circuit

DTC C1361 Short in ABS Motor Fail Safe Relay Circuit


DESCRIPTION

The ABS motor relay supplies power to the ABS pump motor. While the ABS is activated, the ECU turns the motor relay on and operates the ABS pump motor.
If the voltage supplied to the motor relay (BM) is below the DTC's detection threshold due to low voltage from the battery or generator, the DTC may be stored.

DTC Code
DTC Detection Condition
Trouble Area
C0273
When either of the following is detected:
  1. All of the following conditions continue for 0.12 seconds or more.
    1. The IG1 terminal voltage is between 9.5 and 17.2 V.
    2. While initial check and ABS, BA, TRAC or VSC is operating.
    3. Relay contact is open when the relay is ON.
  2. Both of the following conditions continue for 0.12 seconds.
    1. The IG1 terminal voltage is less than 9.5 V.
    2. Relay contact remains open when the relay is ON.
  1. ABS1/VSC1 fuse
  2. ABS motor relay circuit
  3. Brake actuator assembly (ABS motor relay)
C0274
When the motor relay is OFF, the motor relay remains closed for 4 seconds or more.
  1. ABS motor relay circuit
  2. Brake actuator assembly (ABS motor relay)
C1361
Immediately after the ignition switch is turned to ON, the relay contact is closed for 4 seconds when the motor fail safe relay is OFF.
  1. ABS1/VSC1 fuse
  2. ABS motor fail safe relay circuit
  3. Brake actuator assembly (ABS motor fail safe relay)

WIRING DIAGRAM


Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan). Dtc C0273 Open In Abs Motor Relay Circuit


INSPECTION PROCEDURE

NOTICE:
  1. When replacing the brake actuator assembly, perform zero point calibration (YARIS_NCP93 RM000000XHR06QX.html).
  2. Inspect the fuses for circuits related to this system before performing the following inspection procedure.
HINT:
When C1241 is output together with C0273, C0274 and/or C1361 inspect and repair the trouble areas indicated by C1241 first (YARIS_NCP93 RM000000XW60BJX.html).
1.PERFORM ACTIVE TEST USING TECHSTREAM (ABS MOTOR RELAY)

  1. Connect the Techstream to the DLC3.

  1. Start the engine.

  1. Select the Active Test mode on the Techstream (YARIS_NCP93 RM000000XHW09EX.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 4
A


2.INSPECT SKID CONTROL ECU (BM TERMINAL)

  1. Turn the ignition switch off.

  1. Make sure that there is no looseness at the locking part and the connecting part of the connectors.

  1. Check the connector case and terminals for deformation and corrosion.

    Standard condition:
    No deformation or corrosion.


    Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan). Dtc C0273 Open In Abs Motor Relay Circuit

  1. Disconnect the A30 skid control ECU connector.

    Text in Illustration
    *1
    		Front view of wire harness connector
    (to Skid Control ECU)

  1. Measure the voltage according to the value in the table below.

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    A30-24 (BM) - Body ground
    		Always
    		11 to 14 V


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


3.INSPECT SKID CONTROL ECU (GND TERMINAL)


    Yaris. Ncp93, 131.Brake Control Dynamic Control Systems.Anti-Lock Brake System (For Sedan). Dtc C0273 Open In Abs Motor Relay Circuit

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

    Text in Illustration
    *1
    		Front view of wire harness connector
    (to Skid Control ECU)
    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    A30-13 (GND2) - Body ground
    		Always
    		Below 1 Ω


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


4.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 DTC (YARIS_NCP93 RM000000XHV0BQX.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 (YARIS_NCP93 RM000000XHV0BQX.html).

    Result
    Result
    		Proceed to
    DTC is not output
    		A
    DTC 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 (the trouble code is not 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. The DTCs were probably output due to a bad connection of the connector terminal.


B
REPLACE BRAKE ACTUATOR ASSEMBLY (YARIS_NCP93 RM000001BXP02FX.html)
A

CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) (YARIS_NCP93 RM000000XHS09YX.html)