ELECTRONICALLY CONTROLLED BRAKE SYSTEM, Diagnostic DTC:C1231/31

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

DESCRIPTION

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

DTC No. INF Code DTC Detection Condition Trouble Area
C1231/31 701 While steering angle sensor communication is enabled, a malfunction signal output is received during the sensor self-check (sensor malfunction). Steering angle sensor (Spiral cable sub-assembly) internal malfunction
↑ 702 While steering angle sensor communication is enabled, a malfunction signal output is received during the sensor self-check (internal malfunction). ↑
↑ 703 While steering angle sensor communication is enabled, a malfunction signal output is received during the sensor self-check (+B malfunction). ↑

WIRING DIAGRAM

A004FT0E05

CAUTION / NOTICE / HINT

Note

Inspect the fuses for circuits related to this system before performing the following inspection 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 sensor assembly) is malfunctioning, DTCs for the steering angle sensor (spiral cable sub-assembly) may be output even when the steering angle sensor (spiral cable sub-assembly) is normal. When DTCs for a speed sensor or yaw rate and acceleration sensor (airbag sensor assembly) are output together with DTCs for the steering angle sensor (spiral cable sub-assembly), inspect and repair the speed sensor and yaw rate and acceleration sensor (airbag sensor assembly) first, and then inspect and repair the steering angle sensor (spiral cable sub-assembly).

PROCEDURE


  1. CHECK DTC


    1. Clear the DTCs Click here.

    2. Turn the ignition switch off.

    3. Turn the ignition switch to ON (IG) again and check that no CAN communication system DTC is output.


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

      Result
      Result Proceed to
      DTC C1231/31 is output. A
      CAN communication system DTC is output. (w/o Toyota Safety Sense) B
      CAN communication system DTC is output. (w/ Toyota Safety Sense) C
      Speed sensor and/or yaw rate and acceleration sensor DTC is output. D
      DTC C1231/31 is not output. E

      Tech Tips


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

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

      • If speed sensor and the yaw rate and acceleration sensor DTCs are output simultaneously, repair the sensors and inspect the steering angle sensor (spiral cable 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

    CHECK FOR INTERMITTENT PROBLEMS Click here

    A

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE TERMINAL)


    1. A004EL5E02
      Text in Illustration
      *a

      Front view of wire harness connector

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

      Turn the ignition switch off.

    2. Remove the steering wheel and the column cover.

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

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

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      F24-5 (IG) - Body ground Ignition switch ON (IG) 11 to 14 V
      F24-6 (BAT) - Body ground Always 11 to 14 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

    OK

  3. CHECK HARNESS AND CONNECTOR (GROUND TERMINAL)


    1. A004F43E01
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Steering Angle Sensor (Spiral Cable Sub-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
      F24-2 (ESS) - Body ground Always 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.


    OK

    REPLACE SPIRAL CABLE SUB-ASSEMBLY Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)