VEHICLE STABILITY CONTROL 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 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, this 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 judges that pump motor operation is abnormal.

  • ABS NO. 1 fuse

  • ABS motor relay circuit

  • ABS motor relay (brake actuator assembly)

WIRING DIAGRAM

C323088E01

CAUTION / NOTICE / HINT

Note:

  • When replacing the skid control ECU (brake actuator assembly), perform system variant learning and acceleration sensor zero point calibration (Click here).

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

Tip:

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

PROCEDURE

  1. PERFORM ACTIVE TEST USING GTS (MOTOR RELAY)

    1. Connect the GTS to the DLC3.

    2. Start the engine.

    3. Select the Active Test on the GTS (Click here).

      Table 1. ABS/VSC/TRC

      Tester Display

      Test Part

      Control Range

      Diagnostic Note

      Motor Relay

      Motor relay

      Relay ON/OFF

      Operating sound of motor can be heard

    4. Check the operating sound of the pump motor when operating it using the GTS.

    Result

    Result

    Proceed to

    Operating sound is heard.

    A

    Operating sound is not heard.

    B

    CHECK TERMINAL VOLTAGE (+BM TERMINAL)Click here

  2. RECONFIRM DTC

    Tip:

    This DTC is stored when a problem is identified in the skid control ECU (brake actuator assembly).

    The motor relay is in the skid control ECU (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 skid control ECU (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
      Tip:

      • 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 to 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 skid control ECU (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.

    USE SIMULATION METHOD TO CHECK

    (Click here)

    REPLACE BRAKE ACTUATOR ASSEMBLY

    (Click here)

  3. CHECK TERMINAL VOLTAGE (+BM TERMINAL)

    1. Turn the ignition switch off.

    2. U123610E02

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

    3. Disconnect the A78 (for CVT) or A79 (except CVT) skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage (for CVT)

      Tester Connection

      Condition

      Specified Condition

      A78-1 (+BM) - Body ground

      Always

      11 to 14 V

      Standard Voltage (except CVT)

      Tester Connection

      Condition

      Specified Condition

      A79-15 (+BM) - Body ground

      Always

      11 to 14 V
      Table 2. Text in Illustration

      *A

      for CVT

      *B

      except CVT

      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

    REPAIR OR REPLACE HARNESS OR CONNECTOR (+BM CIRCUIT)

  4. CHECK HARNESS AND CONNECTOR (GND2 TERMINAL)

    1. U123611E02

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

      Standard Resistance (for CVT)

      Tester Connection

      Condition

      Specified Condition

      A78-13 (GND2) - Body ground

      Always

      Below 1 Ω

      Standard Resistance (except CVT)

      Tester Connection

      Condition

      Specified Condition

      A79-38 (GND2) - Body ground

      Always

      Below 1 Ω
      Table 3. Text in Illustration

      *A

      for CVT

      *B

      except CVT

      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

    REPLACE BRAKE ACTUATOR ASSEMBLY

    (Click here)

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND2 CIRCUIT)