VEHICLE STABILITY CONTROL SYSTEM, Diagnostic DTC:C0278, C0279

DTC Code DTC Name
C0278 Open in ABS Solenoid Relay Circuit
C0279 Short in ABS Solenoid Relay Circuit

DESCRIPTION

The ABS solenoid relay supplies power to the ABS solenoid and TRC solenoid.

The solenoid relay is turned on 1.5 seconds after the ignition switch is turned on (IG), and is turned off if an open or short in the solenoid is detected by self diagnosis performed when the vehicle starts running.

The ABS solenoid relay is housed in the skid control ECU in the actuator assembly.

DTC Code DTC Detection Condition Trouble Area
C0278

Either of the following is detected:


  1. Both of the following conditions continue for 0.2 seconds or more.


    • The IG1 terminal voltage is 9.5 V or more.

    • The solenoid relay contact is open when the relay is ON.

  2. Both of the following conditions continue for 0.2 seconds or more.


    • The IG1 terminal voltage becomes lower than 9.5 V when the relay is turned on.

    • The relay contact remains open.

  • Fusible link block (VSC NO. 2 fuse)

  • ABS solenoid relay circuit

  • Brake actuator assembly (ABS solenoid relay)
C0279 Immediately after the ignition switch is turned on (IG), the solenoid relay contact is closed for 4 seconds when the relay is turned off.

  • ABS solenoid relay circuit

  • Brake actuator assembly (ABS solenoid relay)

WIRING DIAGRAM

Refer to DTCs C0226, C0236, C0246, C0256 and C1225 Click here.

INSPECTION PROCEDURE

Note

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

Tech Tips

When C1241 and/or C1417 is output together with C0278 and/or C0279, inspect and repair the trouble areas indicated by C1241 and/or C1417 first Click here, or Click here.

PROCEDURE


  1. INSPECT VSC NO. 2 FUSE


    1. A017FDKE02

      Remove the fusible link block from the engine room relay block.

    2. Check if the fusible link is melted.

      OK
      The fusible link is not melted.

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

      Standard resistance
      Tester Connection Condition Specified Condition
      VSC NO. 2 (30 A) fuse - Body ground Always Below 1 Ω

    NG

    REPLACE FUSIBLE LINK BLOCK (VSC NO. 2 FUSE)

    OK

  2. INSPECT SKID CONTROL ECU (+BS TERMINAL)


    1. A017EHAE40

      Install the fusible link block to the engine room relay block with the nut.

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

    3. Disconnect the skid control ECU connector.

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

      Standard voltage
      Tester Connection Condition Specified Condition
      A24-12 (+BS) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (+BS CIRCUIT)

    OK

  3. INSPECT SKID CONTROL ECU (GND1 TERMINAL)


    1. A017EHAE41

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

      Standard resistance
      Tester Connection Condition Specified Condition
      A24-1 (GND1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND1 CIRCUIT)

    OK

  4. RECONFIRM DTC

    Tech Tips

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

    The solenoid circuit is in the brake actuator assembly.

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


    1. Reconnect the skid control ECU connector.

    2. Clear the DTCs Click here.

    3. Start the engine.

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

    5. Check if the same DTC is recorded Click here.

      Result
      Result Proceed to
      DTCs (C0278 and C0279) are not output A
      DTCs (C0278 and/or C0279) are 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 (IG) and the stop light switch off, the ECU performs self diagnosis of the motor and solenoid circuits.

      • If the normal system code is output (no trouble codes are 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.

      • It is suspected that the DTCs were output due to a bad connection of the connector terminal.


    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) Click here