C1231

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1231/31: Steering Angle Sensor Circuit Malfunction

DTC C1231/31 - Steering Angle Sensor Circuit Malfunction

DESCRIPTION

The steering angle sensor signal is sent to the skid control ECU via the CAN communication system. When there is a malfunction in the CAN communication system, it will be detected by the diagnosis function.






WIRING DIAGRAM





INSPECTION PROCEDURE
HINT:
- If a CAN communication malfunction DTC and a related sensor malfunction DTC are output at the same time, the CAN communication malfunction must be repaired before troubleshooting the sensor malfunction DTC.
- 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.
- Start the inspection from "CHECK HARNESS AND CONNECTOR" when using the intelligent tester or Techstream and start from "CHECK DTC" when not using the intelligent tester or Techstream.

PROCEDURE

1. CHECK DTC
(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.
(b) Turn the power switch OFF.
(c) Turn the power switch ON (READY) again and check that no CAN communication system DTC is output CAN Communication System.
(d) Drive the vehicle at a speed of 35 km/h (24 mph), turn the steering wheel to the right and left, and check that no speed sensor and yaw rate sensor DTCs are output.

Result





HINT:
- 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.
- If the speed sensor and the yaw rate sensor DTCs are output simultaneously, repair the sensors first, and then inspect the steering angle sensor.

C -- CHECK FOR CIRCUIT INDICATED BY OUTPUT CODE
B -- GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)
A -- Continue to next step.
2. CHECK HARNESS AND CONNECTOR (STEERING ANGLE SENSOR - BATTERY AND BODY GROUND)





(a) Remove the steering wheel and the column cover lower.
(b) Disconnect the L21 sensor connector.
(c) Measure the voltage according to the value(s) in the table below.
Standard voltage:





(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:





HINT: If troubleshooting has been carried out according to the "PROBLEM SYMPTOMS TABLE", refer back to the table and proceed to the next step Problem Symptoms Table.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- REPLACE STEERING ANGLE SENSOR