ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C120B

DTC Code DTC Name
C120B IG Supply Voltage Low

DESCRIPTION

DTC No. Detection Item DTC Detection Condition Trouble Area Note
C120B IG Supply Voltage Low Master cylinder pressure sensor power supply voltage decrease occurs or history of voltage decrease exists, and defective master cylinder pressure sensor output continues for 1 second or more.
  • Master cylinder pressure sensor output defective

  • Skid control ECU (Brake actuator assembly)

  • VSC NO. 2 fuse

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WIRING DIAGRAM

Refer to DTC C1241.

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CAUTION / NOTICE / HINT

Note


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

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (+BS TERMINAL)


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

    2. Disconnect the A9 skid control ECU (brake actuator assembly) connector.

    3. Turn the engine switch on (IG).

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A9-38 (+BS) - Body ground Always 11 to 14 V
      A9-38 (+BS) - A9-25 (GND1) Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG
    OK
  2. RECONFIRM DTC


    1. Reconnect the A9 skid control ECU (brake actuator assembly) connector.

    2. Clear the DTCs.

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      Chassis > ABS/VSC/TRC > Clear DTCs
    3. Check if the same DTC is output.

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      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C120B is not output. A
      DTC C120B is output. B

    A
    B