Lexus IS250 · Service Manual BRAKE

C1231/31

Diagnostic trouble codes

DESCRIPTION

The steering angle sensor signal is sent to the skid control ECU via CAN communication system. When there is a malfunction in the CAN communication system, it will be detected by the steering angle sensor zero point malfunction diagnostic function.
DTC No.
 DTC Detection Condition
 Trouble Area
C1231/31
 When ECU IG1 terminal voltage is 9.5 V or more, the steering angle sensor malfunction signal is received.
  1. Steering angle sensor
  2. Steering angle sensor circuit
  3. Steering angle sensor power supply
  4. Brake actuator assembly (Skid control ECU)

WIRING DIAGRAM

C109388E02

INSPECTION PROCEDURE

HINT:
  1. When U0073/94, U0123/62, U0124/95 or U0126/63 is output together with C1231/31 inspect and repair the trouble areas indicated by U0073/94, U0123/62, U0124/95 or U0126/63 first.
  2. When the speed sensor or the yaw rate sensor has trouble, DTCs for the steering angle sensor may be output even when the steering angle sensor is normal. When DTCs for the speed sensor or yaw rate sensor are output together with other DTCs for the steering angle sensor, inspect and repair the speed sensor and yaw rate sensor first, and then inspect and repair the steering angle sensor.


1. CHECK DTC

  1. Clear the DTC (Click here).

  1. Turn the engine switch off.

  1. Turn the engine switch on (IG) again and check that no CAN communication system DTC is output.

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

    Result:
    Condition
    		 Proceed to
    No CAN communication system DTC and the speed sensor or yaw rate sensor DTC are output
    		 A
    CAN communication system DTC is output
    		 B
    Speed sensor or yaw rate sensor DTC is output
    		 C (Click here)

    HINT:
    1. If there is a malfunction in the speed sensor or the yaw rate sensor, an abnormal value may be output although the steering angle sensor is normal.
    2. If the speed sensor and the yaw rate sensor DTCs are output simultaneously, repair the sensors and inspect the steering angle sensor.



 B
INSPECT CAN COMMUNICATION SYSTEM

C
REPAIR CIRCUIT INDICATED BY OUTPUT DTC
A


2. INSPECT STEERING ANGLE SENSOR (POWER SOURCE TERMINAL)

  1. G030156E10
    Turn the engine switch off.

  1. Remove the steering wheel and the column cover lower.

  1. Disconnect the steering angle sensor connector.

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

    Standard voltage:
    Tester Connection
    		 Condition
    		 Specified Condition
    J23-1 (IG) - Body ground
    		 Engine switch on (IG)
    		 10 to 14 V
    J23-3 (BAT) - Body ground
    		 Always
    		 10 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)
OK


3. INSPECT STEERING ANGLE SENSOR (GROUND TERMINAL)

  1. G030156E11
    Turn the engine switch off.

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

    Standard resistance:
    Tester Connection
    		 Condition
    		 Specified Condition
    J23-2 (ESS) - Body ground
    		 Always
    		 Below 1 Ω

    HINT:
    If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step (Click here).



 NG
REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)
OK

REPLACE STEERING ANGLE SENSOR


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