VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C142B, C146C, C146D

DTC Code DTC Name
C142B Motor Power Supply Voltage Circuit
C146C Open in ABS Motor Relay Circuit
C146D Short in ABS Motor Relay Circuit

DESCRIPTION

The motor relay and motor fail-safe relay are built into the brake actuator assembly.

During ABS, TRC, VSC, or brake assist operation, the skid control ECU (brake actuator assembly) turns on the motor relay to run the pump motor in the brake actuator assembly.

When a motor system DTC is stored, the motor fail-safe relay cuts the power source supply to the motor relay for fail-safe operation.

These DTCs may be stored when the voltage to the motor relay power source (+BM terminal) is lower than the DTC detection condition due to low output from the battery or alternator.

DTC Code DTC Detection Condition Trouble Area
C142B When voltage at +BS terminal is 9.5 V or higher, open in BM terminal continues for 1 second or more.

  • ABS MTR fuse

  • Skid Control ECU (Brake actuator assembly)

  • Wire harness or connector
C146C When voltage at +BS terminal is 9.5 V or higher and motor relay ON while control operates, relay contact OFF condition continues for 0.12 seconds or more.

  • ABS MTR fuse

  • Brake actuator assembly (Motor relay)

  • Wire harness or connector
C146D

Either of the following is detected:


  1. Overcurrent in motor relay and motor fail-safe relay continues for 0.05 seconds or more.

  2. Motor relay gate voltage malfunction continues for 0.12 seconds or more.

  • Brake actuator assembly (Motor relay)

  • Wire harness or connector

WIRING DIAGRAM

B007V93E01

INSPECTION PROCEDURE

Note


  • When replacing the skid control ECU (brake actuator assembly), perform calibration and store system information Click here.

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

Tech Tips

When DTC C1241 and/or C1417 is output together with DTC C142B, C146C and/or C146D, inspect and repair the trouble areas indicated by DTC C1241 and/or C1417 first Click here, or Click here.

PROCEDURE


  1. CHECK TERMINAL VOLTAGE (+BM TERMINAL)


    1. Turn the ignition switch off.

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

    3. B007V7YE07
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Disconnect the B92 skid control ECU (brake actuator assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      B92-13 (+BM) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (+BM CIRCUIT)

    OK

  2. CHECK HARNESS AND CONNECTOR (GND2 TERMINAL)


    1. B007V7YE05
      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
      B92-1 (GND2) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND2 CIRCUIT)

    OK

  3. RECONFIRM DTC

    Tech Tips

    These codes are 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 inspections and motor relay unit inspections cannot be performed. Be sure to check if any DTCs are output before replacing the brake actuator assembly.


    1. Reconnect the B92 skid control ECU (brake actuator assembly) connector.

    2. Clear the DTC Click here.

    3. Turn the ignition switch off.

    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 recorded Click here.

      Result
      Result Proceed to
      DTCs C142B, C146C and C146D are not output A
      DTCs C142B, C146C and/or C146D are output B

      Tech Tips


      • If a speed signal of 6 km/h (4 mph) or more is input to the skid control ECU (brake actuator assembly), 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 harness, and fuses of the skid control ECU (brake actuator assembly). Make sure that no DTCs are output.

      • If any DTCs are output while jiggling a connector or wire harness from the skid control ECU (brake actuator assembly), 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