ANTI-LOCK BRAKE SYSTEM, Diagnostic DTC:C1241

DTC Code DTC Name
C1241 Low Power Supply Voltage Malfunction

DESCRIPTION

If a malfunction is detected in the power supply circuit, the skid control ECU (housed in the brake actuator assembly) stores this DTC and the fail-safe function prohibits ABS operation.

This DTC is stored when the IG1 terminal voltage deviates from the DTC detection condition due to a malfunction in the power supply or charging circuit, such as the battery or generator circuit, etc.

The DTC is cleared when the IG1 terminal voltage returns to normal.

DTC Code DTC Detection Condition Trouble Area
C1241

One of the following conditions is met:


  1. At a vehicle speed of 3 km/h (2 mph) or more, the IG1 terminal voltage is below 9.5 V for 10 seconds or more.

  2. When the solenoid relay remains on and the IG1 terminal voltage is below 9.5 V, the relay contact is open for 0.22 seconds or more.

  3. With the IG1 terminal voltage at 9.5 V or less, the vehicle speed sensor power supply decreases for 60 seconds or more.

  • ECU-IG NO. 1 fuse

  • Battery

  • Charging system

  • Power source circuit

  • Internal power supply circuit of the skid control ECU

WIRING DIAGRAM

A009A8BE05

INSPECTION PROCEDURE

Note


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

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

PROCEDURE


  1. CHECK TERMINAL VOLTAGE (IG1)


    1. Disconnect the A6 skid control ECU connector.

    2. A0095SVE08
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Skid Control ECU)

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A6-34 (IG1) - Body ground Ignition switch ON 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)


    1. Disconnect the A6 skid control ECU connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A6-1 (GND1) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. RECONFIRM DTC


    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 output Click here.

      Result
      Result Proceed to
      DTC not output A
      DTC output B

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here

    A

    USE SIMULATION METHOD TO CHECK Click here