C1231

BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1231/31: Steering Angle Sensor Circuit Malfunction
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
- When U0073/94, U0293/59, U0123/62, U0124/95, U0126/63 or U0130/68 is output together with C1231/31, inspect and repair the trouble areas indicated by U0073/94, U0123/62, U0124/95, U0126/63 or U0130/68 first.
- 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 Techstream and start from "CHECK DTC" when not using the Techstream.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)

(a) Using the Techstream, check for any momentary interruption in the wire harness and connectors between the skid control ECU and the steering angle sensor Check for Intermittent Problems.

ABS/VSC/TRAC

OK:

There are no momentary interruptions.

HINT
Perform the above inspection before removing the sensor and connector.

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (STEERING ANGLE SENSOR - SKID CONTROL ECU)
OK -- Continue to next step.

2. CHECK DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the engine switch off.

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

(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 and inspect the steering angle sensor.

B -- GO TO CAN COMMUNICATION SYSTEM How to Proceed With Troubleshooting

C -- CHECK FOR CIRCUIT INDICATED BY OUTPUT CODE Electronically Controlled Brake System
A -- Continue to next step.

3. CHECK TERMINAL VOLTAGE (IG, BAT)

(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 (IG, BAT OR ESS CIRCUIT)

OK -- REPLACE STEERING ANGLE SENSOR Removal

4. REPAIR OR REPLACE HARNESS OR CONNECTOR (STEERING ANGLE SENSOR - SKID CONTROL ECU)

NEXT -- Continue to next step.

5. RECONFIRM DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Start the engine.

(c) Drive the vehicle at a speed of 35 km/h (24 mph) or more, and turn the steering wheel to the right and left.

(d) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result