VEHICLE STABILITY CONTROL SYSTEM (for Vacuum Brake Booster), Diagnostic DTC:C0273, C0274, C1361

DTC Code DTC Name
C0273 Open in ABS Motor Relay Circuit
C0274 Short in ABS Motor Relay Circuit
C1361 Short in ABS Motor Fail Safe Relay Circuit

DESCRIPTION

The motor relay supplies power to the pump motor. While the ABS is activated, the ECU turns the motor relay on and operates the pump motor.

If the voltage supplied to the motor relay (+BM) is below the DTC detection threshold due to low voltage from the battery or generator, these DTCs may be stored.

DTC Code DTC Detection Condition Trouble Area
C0273

Either condition is met:


  1. All conditions are met for 0.12 seconds or more.


    • The IG1 terminal voltage is between 9.5 and 17.2 V.

    • During initial check and ABS, BA, TRC or VSC is operating.

    • The relay contact is open when the relay is on.

  2. Both conditions are met for 0.12 seconds.


    • The IG1 terminal voltage is below 9.5 V.

    • The relay contact remains open when the relay is on.

  • ABS NO. 1 fuse

  • Motor relay circuit

  • Brake actuator assembly (Motor relay)
C0274 When the motor relay is off, the motor relay remains closed for 4 seconds or more.

  • Motor relay circuit

  • Brake actuator assembly (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.

  • ABS NO. 1 fuse

  • Motor fail-safe relay circuit

  • Brake actuator assembly (Motor fail-safe relay)

WIRING DIAGRAM

A00O8PGE06

INSPECTION PROCEDURE

Note


  • When replacing the brake actuator assembly, perform calibration Click here.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

Tech Tips

When DTC C1241 is output together with DTC C0273, C0274 and/or C1361, inspect and repair the trouble areas indicated by DTC C1241 first Click here.

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER (MOTOR RELAY)


    1. Turn the ignition switch off.

    2. Connect the intelligent tester to the DLC3.

    3. Start the engine.

    4. Turn the intelligent tester on.

    5. Enter the following menus: Chassis / ABS/VSC/TRC / Active Test.

      ABS/VSC/TRC
      Tester Display Test Part Control Range Diagnostic Note
      Motor Relay Motor relay Relay ON / OFF The operating sound of the motor can be heard.

    6. Check the operating sound of the motor relay when operating it with the intelligent tester.

      Result
      Result Proceed to
      Operating sound is not heard A
      Operating sound is heard B

    B

    RECONFIRM DTC Click here

    A

  2. CHECK TERMINAL VOLTAGE (+BM)


    1. Turn the ignition switch off.

    2. Disconnect the A6 skid control ECU connector.

    3. A00O37ME13
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A6-24 (+BM) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (GND2 TERMINAL)


    1. Disconnect the A6 skid control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A6-13 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. RECONFIRM DTC

    Tech Tips

    This code is stored when a problem is identified in the brake actuator assembly.

    The motor relay is in the brake actuator assembly.

    Therefore, motor relay inspections and motor relay unit inspections cannot be performed. Be sure to check if the DTC is output before replacing the brake actuator assembly.


    1. Turn the ignition switch off.

    2. Reconnect the skid control ECU connector.

    3. Clear the DTCs Click here.

    4. Start the engine.

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

    6. Check if the same DTC is output Click here.

      Result
      Result Proceed to
      DTC not output A
      DTC output B

      Tech Tips


      • 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.

      • If the normal system code is output (the trouble code is not output), slightly jiggle the connectors, wire harnesses, and fuses of the brake actuator assembly. Make sure that no DTCs are output.

      • 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. The DTCs were probably output due to a bad connection of the connector terminal.


    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    USE SIMULATION METHOD TO CHECK Click here