ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1231/31

DTC Code DTC Name
C1231/31 Steering Angle Sensor Circuit Malfunction

DESCRIPTION

The skid control ECU (brake booster with master cylinder assembly) receives steering angle sensor (spiral cable with sensor sub-assembly) signals via CAN communication. When a malfunction occurs in the communication line with the steering angle sensor (spiral cable with sensor sub-assembly), DTC U0126/63 (Lost Communication with Steering Angle Sensor Module) is stored.

DTC No. Detection Item INF Code DTC Detection Condition Trouble Area Note
C1231/31 Steering Angle Sensor Circuit Malfunction

701

702

703

  • INF Code: 701


    • While steering angle sensor communication is enabled, a malfunction signal output is received during the sensor self-check (sensor malfunction).

  • INF Code: 702


    • While steering angle sensor communication is enabled, a malfunction signal output is received during the sensor self-check (internal malfunction).

  • INF Code: 703


    • While steering angle sensor communication is enabled, a malfunction signal output is received during the sensor self-check (+B malfunction).

 Steering angle sensor (Spiral cable with sensor sub-assembly) internal malfunction VSC DTC

WIRING DIAGRAM

A01MGW8E03

CAUTION / NOTICE / HINT

Note

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

Tech Tips


  • When U0126/63 is output together with C1231/31, inspect and repair the trouble areas indicated by U0126/63 first.

    Click here

  • When a speed sensor or yaw rate and acceleration sensor (airbag ECU assembly) is malfunctioning, DTCs for the steering angle sensor (spiral cable with sensor sub-assembly) may be output even when the steering angle sensor (spiral cable with sensor sub-assembly) is normal. When DTCs for a speed sensor or the yaw rate and acceleration sensor (airbag ECU assembly) are output together with DTCs for the steering angle sensor (spiral cable with sensor sub-assembly), inspect and repair the speed sensor and yaw rate and acceleration sensor (airbag ECU assembly) first, and then inspect and repair the steering angle sensor (spiral cable with sensor sub-assembly).

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs.

      Click here


      Chassis > ABS/VSC/TRC > Clear DTCs

    2. Turn the power switch off.

    3. Turn the power switch on (IG) again and check that no CAN communication system DTCs are output.


    4. Drive the vehicle at a speed of 35 km/h (22 mph), turn the steering wheel to the right and left, and check that no speed sensor and/or yaw rate and acceleration sensor DTCs are output.

      Click here


      Chassis > ABS/VSC/TRC > Trouble Codes
      Result
      Result Proceed to
      DTC C1231/31 is output. A
      CAN communication system DTCs are output (for RHD). B
      CAN communication system DTCs are output (for LHD). C
      Speed sensor and/or yaw rate and acceleration sensor DTCs are output. D
      DTC C1231/31 is not output. E

      Tech Tips


      • When CAN communication system DTCs are output, repair the CAN communication system before repairing each corresponding sensor.

      • If there is a malfunction in a speed sensor or the yaw rate and acceleration sensor (airbag ECU assembly), an abnormal value may be output even though the steering angle sensor (spiral cable with sensor sub-assembly) is normal.

      • If speed sensor and yaw rate and acceleration sensor DTCs are output simultaneously, repair the sensors and inspect the steering angle sensor (spiral cable with sensor sub-assembly).


    B

    INSPECT CAN COMMUNICATION SYSTEM Click here

    C

    INSPECT CAN COMMUNICATION SYSTEM Click here

    D

    REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Click here

    E

    USE SIMULATION METHOD TO CHECK Click here

    A

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. A01MGTCC06
      *a

      Front view of wire harness connector

      (to Steering Angle Sensor (Spiral Cable with Sensor Sub-assembly))

      Turn the power switch off.

    2. Remove the steering wheel and column cover.

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

    4. Disconnect the G3 steering angle sensor (spiral cable with sensor sub-assembly) connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      G3-4 (IG1) - Body ground Power switch on (IG) 11 to 14 V
      G3-5 (BAT) - Body ground Always 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  3. CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)


    1. A01MGTCC07
      *a

      Front view of wire harness connector

      (to Steering Angle Sensor (Spiral Cable with Sensor Sub-assembly))

      Turn the power switch off.

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

      Note

      Before measuring the resistance of the steering angle sensor (spiral with sensor cable sub-assembly), turn the power switch off and leave the vehicle for 1 minute or more without operating the key, switches or opening or closing the doors.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G3-1 (ESS) - Body ground 1 minute after power switch off Below 1 Ω

      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

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE SPIRAL CABLE WITH SENSOR SUB-ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)