VEHICLE STABILITY CONTROL 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 (brake actuator assembly) stores this DTC and the fail-safe function prohibits ABS operation.

This DTC is stored when the +BS terminal voltage deviates due to a malfunction in the power supply or charging circuit such as the battery or alternator circuit, etc.

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

DTC No. Detection Item DTC Detection Condition Trouble Area
C1241 Low Power Supply Voltage Malfunction

Any of the following is detected:


  1. When vehicle speed is 3 km/h (2 mph) or more, +BS terminal voltage is continuously below 9.5 V for 10 seconds or more.

  2. When solenoid relay is on, +BS terminal voltage is below 9.5 V and relay contact is off for 0.22 seconds or more.

  3. When +BS terminal voltage is below 9.5 V, power supply voltage of vehicle speed sensor is continuously low for 60 seconds or more.

  4. When fail-safe motor relay is on and +BS terminal voltage is below 9.5 V, fail-safe motor relay overcurrent continues for 0.05 seconds or more.

  • Battery

  • Charging system

  • Power source circuit

  • Internal power supply circuit of the skid control ECU (brake actuator assembly)

WIRING DIAGRAM

A0028IDE13
*a from Battery
*b ABS NO. 2
*c Skid Control ECU (Brake Actuator Assembly)

CAUTION / NOTICE / HINT

Note


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

    Click here

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

PROCEDURE


  1. CHECK BATTERY


    1. Check the battery voltage.

      Standard Voltage
      Tester Connection Condition Specified Condition
      Battery Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 1AR-FE: Click here
    CHECK OR REPLACE CHARGING SYSTEM OR BATTERY for 2GR-FKS: Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (+BS TERMINAL)


    1. A002AHOC14
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

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

    2. Disconnect the A86 skid control ECU (brake actuator assembly) connector.

    3. Turn the ignition switch to ON.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A86-38 (+BS) - Body ground Ignition switch ON 11 to 14 V
      A86-38 (+BS) - A86-25 (GND1) Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (IG1 CIRCUIT)

    OK

  3. CHECK HARNESS AND CONNECTOR (GND1 TERMINAL)


    1. A002AHOC15
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Actuator Assembly))

      Turn the ignition switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A86-25 (GND1) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

    OK

  4. RECONFIRM DTC


    1. Reconnect the A86 skid control ECU (brake actuator assembly) connector.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the ignition switch off.

    4. Start the engine.

    5. Perform a road test.

    6. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1241 is not output. A
      DTC C1241 is output. B

      Tech Tips

      If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts.

      Click here


    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE BRAKE ACTUATOR ASSEMBLY Click here