Steering Angle Sensor Circuit Malfunction (C1231/31)

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 steering angle sensor zero point malfunction diagnostic function.

DTC Code	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.	Steering angle sensor Steering angle sensor circuit Steering angle sensor power supply Brake actuator assembly (Skid control ECU)

WIRING DIAGRAM
CAUTION / NOTICE / HINT

HINT:

• When U0073/94, U0123/62 and/or U0126/63 is output together with C1231/31, inspect and repair the trouble areas indicated by U0073/94, U0123/62 and/or U0126/63 first (See page ).


• When the speed sensor or the yaw rate and acceleration 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 and acceleration sensor are output together with other DTCs for the steering angle sensor, inspect and repair the speed sensor and yaw rate and acceleration sensor first, and then inspect and repair the steering angle sensor.

PROCEDURE

1. CHECK DTC

(a) Clear the DTCs (See page ).

(b) Turn the ignition switch off.

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

(d) Drive the vehicle and turn the steering wheel to the right and left at a speed of 35 km/h and check that no speed sensor and yaw rate and acceleration sensor DTCs are output (See page ).

Result	Proceed to
No CAN communication system DTC and the speed sensor or yaw rate and acceleration sensor DTC are output	A
CAN communication system DTC is output	B
Speed sensor or yaw rate and acceleration sensor DTC is output	C

HINT:

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

B

INSPECT CAN COMMUNICATION SYSTEM

C

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

A

1. INSPECT STEERING ANGLE SENSOR (POWER SOURCE TERMINAL)

(a) Turn the ignition switch off.

(b) Remove the steering wheel and the column cover.

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

(d) Disconnect the steering angle sensor connector.

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

Standard Voltage:

Tester Connection	Condition	Specified Condition
D35-5 (IG) - Body ground	Ignition switch ON	11 to 14 V
D35-6 (BAT) - Body ground	Always	11 to 14 V

Text in Illustration

*1	Front view of wire harness connector (to Spiral Cable Sub-assembly (Steering Angle Sensor))

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)

OK

1. INSPECT STEERING ANGLE SENSOR (GROUND TERMINAL)

(a) Turn the ignition switch off.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
D35-2 (ESS) - Body ground	Always	Below 1 Ω

Text in Illustration

*1	Front view of wire harness connector (to Spiral Cable Sub-assembly (Steering Angle Sensor))

HINT:

If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step (See page ).

OK

REPLACE SPIRAL CABLE SUB-ASSEMBLY (STEERING ANGLE SENSOR)

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)