ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:C146C

DTC Code DTC Name
C146C Open in ABS Motor Relay Circuit

DESCRIPTION

The ABS motor relay supplies power to the pump motor. While the ABS is activated, the skid control ECU (brake actuator assembly) turns the ABS motor relay on to operate the pump motor.

If the voltage supplied to the ABS motor relay (+BM) is too low due to low voltage from the battery or alternator, the DTC may be stored.

DTC No. DTC Detection Condition Trouble Area
C146C

Any of the following is detected:


  1. When the ABS motor relay is actuated, voltage is not supplied to the pump motor.

  2. When the ABS motor relay is not actuated, voltage in the pump motor is high.

  3. The skid control ECU (brake actuator assembly) judges that pump motor operation is abnormal.

  • ABS NO. 1 fuse (Fusible link block assembly)

  • ABS motor relay circuit

  • ABS motor relay (Brake actuator assembly)

WIRING DIAGRAM

A0137A4E02

INSPECTION PROCEDURE

Note

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

Tech Tips

When C1241 and/or C1417 is output together with C146C, inspect and repair the trouble areas indicated by C1241 and/or C1417 first Click here, and/or Click here.

PROCEDURE


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


    1. Connect the intelligent tester to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the intelligent tester on.

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

    5. According to the display on the intelligent tester, perform the Active Test.

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

    6. Check the operating sound of the pump motor when operating it using the intelligent tester.

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

    B

    CHECK HARNESS AND CONNECTOR (+BM TERMINAL) Click here

    A

  2. RECONFIRM DTC

    Tech Tips

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

    The ABS motor relay is in the brake actuator assembly.

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


    1. Turn the ignition switch off.

    2. Clear the DTCs Click here.

    3. Turn the ignition switch off.

    4. Start the engine.

    5. Drive the vehicle at a speed of 40 km/h (25 mph) or more for 30 seconds or more.

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

      Result
      Result Proceed to
      DTC C146C is not output. A
      DTC C146C is output. B

      Tech Tips


      • If a speed signal of 40 km/h (25 mph) or more is received by the skid control ECU (brake actuator assembly) with the ignition switch ON, the skid control ECU (brake actuator assembly) performs self diagnosis of the motor circuit.

      • If the normal system code is output (No DTCs are output), slightly jiggle the connectors, wire harness, and fuses of the brake actuator assembly.

      • If any DTCs are output while jiggling a connector or wire harness of the skid control ECU (brake actuator assembly), inspect and repair the connector or wire harness.

      • If no DTCs were output when reconfirming DTCs, checking for intermittent problems is necessary because it is suspected that the original DTCs were stored due to the poor connection of a connector terminal.


    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS

  3. CHECK HARNESS AND CONNECTOR (+BM TERMINAL)


    1. Disconnect the skid control ECU (brake actuator assembly) connector.

    2. A0136PEE05
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A46-1 (+BM) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (+BM CIRCUIT)

    OK

  4. CHECK HARNESS AND CONNECTOR (GND2 TERMINAL)


    1. A0136PEE06
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A46-13 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND2 CIRCUIT)

    OK

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here