ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1241/41, C1242/42

DTC Code DTC Name
C1241/41 Low Battery Positive Voltage
C1242/42 Open in IG1 / IG2 Power Source Circuit

DESCRIPTION

If a malfunction is detected in the power supply circuit, the skid control ECU assembly power source voltage drops, or there is insufficient voltage to operate the ABS main relay, the skid control ECU assembly will store these DTCs.

These DTCs may also be stored if the auxiliary battery voltage drops below 9.5 V.

Tech Tips

DTC C1256/57 (Accumulator Low Pressure) may also be memorized if there is a drop in power source voltage.

DTC No. Detection Item INF Code DTC Detection Condition Trouble Area Note
C1241/41 Low Battery Positive Voltage

81*1

82*1

83*1

91*2

92*2

93*2

94*2

  • INF Code: 81


    • System ABS main relay 1 is under the following conditions when the power switch is on (READY):


      1. With the ABS main relay 1 and the relay contact on, the voltage of relay power supply terminal (BS01) is less than 8.9 V and the actual current, which is supplied by the relay, does not reach the specified value at any of the linear solenoids for 0.03 seconds or more.

      2. With the ABS main relay 1 and the relay contact on, the voltage of relay power supply terminal (BS01) is less than 8.9 V and the brake pedal is not depressed for 3 seconds or more.

      3. When 0.05 seconds have elapsed after ABS main relay 1 is turned on and the relay contact is on, the voltage of relay power supply terminal (BS01) is less than 8.9 V and even one wheel is prohibited from braking while depressing the brake pedal.

      4. While the ABS main relay 1 on continues, skid control ECU assembly activation power source input terminal (+BI1 or +BI3) becomes lower than 9.1 V and the relay contact off continues for 0.2 seconds or more.

      5. With the pressure sensor power supply voltage (VCM) 4.7 V or less or 5.3 V or more, skid control ECU assembly activation power source input terminal (+BI1 or +BI3) in the relevant lines is 9.1 V or less for 0.05 seconds or more.

      6. The brake pedal stroke sensor output voltage 1 (SKS) or brake pedal stroke sensor output voltage 2 (SKS2) terminal voltage remains below 0.26 V or 4.89 V or higher, or the brake pedal stroke sensor power source voltage (VCSK) remains 4.67 V or less or 5.41 V or higher for 0.2 seconds or more

  • INF Code: 82


    • System ABS main relay 2 is under the following conditions when the power switch is on (READY):


      1. With the ABS main relay 2 and the relay contact on, the voltage of relay power supply terminal (BS02) is less than 8.9 V and the actual current, which is supplied by the relay, does not reach the specified value at any of the linear solenoids for 0.03 seconds or more.

      2. With the ABS main relay 2 and the relay contact on, the voltage of relay power supply terminal (BS02) is less than 8.9 V and the brake pedal is not depressed for 3 seconds or more.

      3. When 0.05 seconds have elapsed after ABS main relay 2 is turned on and the relay contact is on, the voltage of relay power supply terminal (BS02) is less than 8.9 V and even one wheel is prohibited from braking while depressing the brake pedal.

      4. While the ABS main relay 2 on continues, skid control ECU assembly activation power source input terminal (+BI2 or +BI4) becomes lower than 9.1 V and the relay contact off continues for 0.2 seconds or more.

      5. With the pressure sensor power supply voltage (VCM2) 4.7 V or less or 5.3 V or more, skid control ECU assembly activation power source input terminal (+BI2 or +BI4) in the relevant lines is 9.1 V or less for 0.05 seconds or more.

      6. The brake pedal stroke sensor output voltage 1 (SKS) or brake pedal stroke sensor output voltage 2 (SKS2) terminal voltage remains below 0.26 V or 4.89 V or higher, or the brake pedal stroke sensor power source voltage (VCSK) remains 4.67 V or less or 5.41 V or higher for 0.2 seconds or more

  • INF Code: 83


    • With the power switch on (READY), the capacitor mode signal is received from the brake control power supply with bracket assembly while the vehicle is driven at low speed for 7 seconds or more, or the vehicle is driven at medium to high speed for 3 seconds or more.

  • INF Code: 91, 92


    • Either of the following is detected:


      1. The voltage of terminal IG1 or IG2 is 3.5 V or more, and when the vehicle speed is 3 km/h (2 mph) or more, the voltage of terminal IG1 is 9.5 V or less for 10 seconds or more.

      2. The voltage of terminal IG1 or IG2 is 3.5 V or more, and when the vehicle speed is 3 km/h (2 mph) or more, the voltage of terminal (+BI1 and +BI3 or +BI2 and +BI4) is 9.1 V or less for 10 seconds or more.

  • INF Code: 93, 94


    • Either of the following is detected:


      1. The voltage of terminal IG1 is 3.5 V or more, and with the voltage of terminal +BI1 and +BI3 at 9.1 V or less, the front wheel speed sensor RH and rear wheel speed sensor LH power supply voltage decreases for 60 seconds or more.

      2. The voltage of terminal IG2 is 3.5 V or more, and with the voltage of terminal +BI2 and +BI4 at 9.1 V or less, the front wheel speed sensor LH and rear wheel speed sensor RH power supply voltage decreases for 60 seconds or more.

  • INF Code: 81, 82, 91, 92


    • Improperly connected connector, deformation or corrosion of terminals

    • Auxiliary battery

    • Hybrid control system (Charging circuit)

  • INF Code: 83


    • Auxiliary battery

    • Hybrid control system (Charging circuit)

    • Brake control power supply with bracket assembly

  • INF Code: 93, 94


    • Open or short in IG1 circuit

    • Improperly connected connector, deformation or corrosion of terminals

    • Auxiliary battery

    • Hybrid control system (Charging circuit)

    • Skid control ECU assembly

*1: Electronically controlled brake system DTC

*2: ABS DTC
C1242/42 Open in IG1 / IG2 Power Source Circuit

87

88

  • INF Code: 87


    • The power supply voltage is not applied to the IG1 terminal, power supply voltage is applied to the IG2 terminal, and +BI1 terminal voltage is 9.5 V or more for 4 seconds or more.

  • INF Code: 88


    • The power supply voltage is applied to the IG1 terminal, power supply voltage is not applied to the IG2 terminal, and +BI1 terminal voltage is 9.5 V or more for 4 seconds or more.

  • INF Code: 87


    • Open or short in IG1 circuit

    • Improperly connected connector, deformation or corrosion of terminals

    • IG start circuit (for power source mode)

    • Auxiliary battery

    • Hybrid control system (Charging circuit)

    • Skid control ECU assembly

  • INF Code: 88


    • Open or short in IG2 circuit

    • Improperly connected connector, deformation or corrosion of terminals

    • IG start circuit (for power source mode)

    • Auxiliary battery

    • Hybrid control system (Charging circuit)

    • Skid control ECU assembly

 Electronically controlled brake system DTC
DTC No. Brake warning light / yellow (minor malfunction) code ABS warning light code Slip indicator light code Brake hold standby indicator light code
C1241*1 41 42 45 21
C1241*2 36 41 43 21
C1242 42 42 45 21
*1: Electronically controlled brake system DTC
*2: ABS DTC

WIRING DIAGRAM

B004BXDE07

Figure 1. for RHD:

B004C1YE13

Figure 2. for LHD:

B004C1YE14

CAUTION / NOTICE / HINT

Note


  • When replacing the skid control ECU assembly, perform initialization and calibration of the linear solenoid valve.

    Click here

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

PROCEDURE


  1. CHECK HYBRID CONTROL SYSTEM


    1. Check if hybrid control system DTCs are output.

      Click here


      Powertrain > Hybrid Control > Trouble Codes
      Result
      Result Proceed to
      DTCs are not output. A
      DTCs are output. B

    B

    INSPECT HYBRID CONTROL SYSTEM Click here

    A

  2. CHECK DTC


    1. Check that no ABS main relay, brake pedal stroke sensor and/or brake control power supply with bracket assembly malfunction DTCs are output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      ABS main relay and brake control power supply with bracket assembly malfunction DTCs are not output. A
      ABS main relay and/or brake control power supply with bracket assembly malfunction DTCs are output. B

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  3. CHECK AUXILIARY BATTERY


    1. Check the auxiliary battery voltage.

      Standard Voltage
      Tester Connection Condition Specified Condition
      Auxiliary battery Power switch on (IG) 11 to 14 V
      Auxiliary battery Power switch on (READY) 11 to 15.5 V
      Result
      Proceed to
      OK
      NG

    NG

    CHARGE OR REPLACE AUXILIARY BATTERY

    OK

  4. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


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

      B004ADQC09
      *a

      Front view of wire harness connector

      (to Skid Control ECU Assembly)

      		 - -

    2. Disconnect the A9, A11 and A10 skid control ECU assembly connectors.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A9-4 (+BI1) - Body ground Always 11 to 14 V
      A11-5 (+BI2) - Body ground Always 11 to 14 V
      A9-5 (+BI3) - Body ground Always 11 to 14 V
      A11-6 (+BI4) - Body ground Always 11 to 14 V
      A9-2 (IG1) - Body ground Power switch on (IG) 11 to 14 V
      A10-5 (IG2) - Body ground Power switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  5. CHECK HARNESS AND CONNECTOR (GND TERMINAL)


    1. Turn the power switch off.

      B004B77C24
      *a

      Front view of wire harness connector

      (to Skid Control ECU Assembly)

      		 - -

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

    3. Disconnect the A8 skid control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A8-1 (GND) - Body ground Always Below 1 Ω
      A9-3 (GND2) - Body ground Always Below 1 Ω
      A9-1 (GND3) - Body ground Always Below 1 Ω
      A10-3 (GND4) - Body ground Always Below 1 Ω
      A10-1 (GND5) - Body ground Always Below 1 Ω
      A11-3 (GND6) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

    OK

  6. RECONFIRM DTC


    1. Reconnect the A9, A11, A8 and A10 skid control ECU assembly connectors.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the power switch off.

    4. Turn the power switch on (IG).

    5. Check if the same DTC is output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTCs C1241/41 and C1242/42 are not output. A
      DTCs C1241/41 and/or C1242/42 are output. B

    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE SKID CONTROL ECU ASSEMBLY for RHD: Click here
    REPLACE SKID CONTROL ECU ASSEMBLY for LHD: Click here