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 (brake booster with master cylinder assembly) power source voltage drops, or there is insufficient voltage to operate the ABS main relay, the skid control ECU (brake booster with master cylinder assembly) will store these DTCs.

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

Tech Tips

DTC C1256/56 (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

101*1

102*1

551*2

552*2

553*2

  • INF Code: 101


    • Any of the following is detected when the BS terminal voltage is 9.3 V or less:


      1. Vehicle not decelerated (brake pedal is not depressed) for 3 seconds or more.

      2. While depressing the brake pedal, linear solenoid current does not satisfy 1.34 A.

      3. Vehicle decelerated (brake pedal is depressed) for 0.06 seconds.

  • INF Code: 102


    • Any of the following is detected when the ECU internal voltage is 6.8 V or less:


      1. When main relay ON is requested, voltage of the relay connection does not exceed 3.5 V for 0.22 seconds or more.

      2. Sensor supply voltage is 4.75 V or less, or 5.25 V or more for 0.06 seconds.

      3. Accumulator pressure sensor output voltage is 4.54 V or less, or 5.46 V or more for 0.06 seconds.

  • INF Code: 551


    • When driving at 3 km/h (1.9 mph) or more, IG1 terminal voltage is 9.5 V or less, or VM1 voltage is 8.6 V or less for 10 seconds or more.

  • INF Code: 552


    • When VM1 voltage is 8.6 V or less, sensor supply voltage is low for 60 seconds or more.

  • INF Code: 553


    • VM1 voltage is 16.6 V or more for 0.8 seconds.

  • Improperly connected connector, deformation or corrosion of terminals

  • Auxiliary battery

  • Hybrid control system (Charging circuit)

  • Skid control ECU (Brake booster with master cylinder assembly)

*1: Electronically controlled brake system DTC

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

111

112

  • INF Code: 111


    • Voltage is not applied to the IG1 terminal (less than 3.5 V), and applied to the IG2 terminal (9.5 V or more) for 4 seconds or more.

  • INF Code: 112


    • Voltage is not applied to the IG2 terminal (less than 3.5 V), and applied to the IG1 terminal (9.5 V or more) for 4 seconds or more.

  • INF Code: 111


    • Open or short in IG1 circuit

    • Improperly connected connector, deformation or corrosion of terminals

    • Entry and start system (IG start circuit)

    • Auxiliary battery

    • Hybrid control system (Charging circuit)

    • Skid control ECU (Brake booster with master cylinder assembly)

  • INF Code: 112


    • Open or short in IG2 circuit

    • Improperly connected connector, deformation or corrosion of terminals

    • Entry and start system (IG start circuit)

    • Auxiliary battery

    • Hybrid control system (Charging circuit)

    • Skid control ECU (Brake booster with master cylinder assembly)

 Electronically controlled brake system DTC

WIRING DIAGRAM

A01MJZ6E14

CAUTION / NOTICE / HINT

Note


  • When replacing the skid control ECU (brake booster with master cylinder 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 ENTRY AND START SYSTEM (for Start Function)


    1. Check if entry and start system (for start function) DTCs are output.

      Click here


      Body Electrical > Entry&Start > Trouble Codes
      Result
      Result Proceed to
      DTCs are not output. A
      DTCs are output. B

    B

    INSPECT ENTRY AND START SYSTEM (for Start Function) Click here

    A

  2. CHECK HYBRID CONTROL SYSTEM


    1. Check if hybrid control system DTCs are output.

      Click here


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

    B

    INSPECT HYBRID CONTROL SYSTEM Click here

    A

  3. CHECK DTC


    1. Check that no main relay malfunction DTCs are output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      Main relay malfunction DTCs are not output. A
      Main relay malfunction DTCs are output. B

    B

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    A

  4. CHECK AUXILIARY BATTERY


    1. Check the auxiliary battery voltage.

      Standard Voltage
      Tester Connection Switch 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

  5. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. A01MK1FC08
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

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

    2. Disconnect the A63 skid control ECU (brake booster with master cylinder assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A63-14 (BI) - Body ground Always 11 to 14 V
      A63-15 (BS) - Body ground Always 11 to 14 V
      A63-16 (IG1) - Body ground Power switch on (IG) 11 to 14 V
      A63-12 (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

  6. CHECK HARNESS AND CONNECTOR (GND TERMINAL)


    1. A01MK1FC18
      *a

      Front view of wire harness connector

      (to Skid Control ECU (Brake Booster with Master Cylinder Assembly))

      Turn the power switch off.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A63-28 (GND) - Body ground Always Below 1 Ω
      A63-27 (GND2) - Body ground Always Below 1 Ω
      A63-26 (GND3) - Body ground Always Below 1 Ω
      A63-25 (GND4) - Body ground Always Below 1 Ω
      A63-24 (GND5) - Body ground Always Below 1 Ω
      A63-23 (GND6) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GND CIRCUIT)

    OK

  7. RECONFIRM DTC


    1. Reconnect the A63 skid control ECU (brake booster with master cylinder assembly) connector.

    2. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    3. Turn the power switch off.

    4. Turn the power switch on (READY).

    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
      DTCs C1241/41 and C1242/42 are not output. A
      DTCs C1241/41 and/or C1242/42 are output (for RHD). B
      DTCs C1241/41 and/or C1242/42 are output (for LHD). C

      Tech Tips

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

      Click here


    A

    USE SIMULATION METHOD TO CHECK Click here

    B

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here

    C

    REPLACE BRAKE BOOSTER WITH MASTER CYLINDER ASSEMBLY Click here