DTC C1231: Steering Angle Sensor Circuit [06/2017 - 10/2020]: Procedure

1. Clear the DTCs.

   Chassis > ABS/VSC/TRAC/EPB > Clear DTCs 

2. Turn the ignition switch off.
3. Turn the ignition switch to ON again and check that no CAN communication system DTCs are output.

   Refer to HOW TO PROCEED WITH TROUBLESHOOTING [03/2017 - ]

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

   Chassis > ABS/VSC/TRAC/EPB > Trouble Codes 

   Result

   Result	Proceed to
   C1231 is output	A
   CAN communication system DTCs are output	B
   Speed sensor and/or yaw rate and acceleration sensor DTCs are output	C
   C1231 is not output	D

   HINT: 

   • When CAN communication system DTCs are output, repair the CAN communication system before repairing each corresponding sensor.
   • If there is a malfunction in a speed sensor or the yaw rate and acceleration sensor (airbag sensor assembly), an abnormal value may be output even though the steering angle sensor is normal.
   • If speed sensor and yaw rate and acceleration sensor DTCs are output simultaneously, repair the sensors and inspect the steering angle sensor.

Result: 

B 

INSPECT CAN COMMUNICATION SYSTEM. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [03/2017 - ] 

Result: 

C 

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS. Refer to  DIAGNOSTIC TROUBLE CODE CHART [06/2017 - 10/2020] 

Result: 

D 

USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [06/2017 - 08/2018]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2018 - 09/2019]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2019 - 03/2020]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [03/2020 - 10/2020] 

Result: 

A 

See step  2

1. Turn the ignition switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Steering Angle Sensor)

2. Remove the steering wheel and column cover.
3. Make sure that there is no looseness at the locking part and the connecting part of the connector.

   OK

   The connector is securely connected.

4. Disconnect the K71 steering angle sensor connector.
5. Check both the connector case and the terminals for deformation and corrosion.

   OK

   No deformation or corrosion.

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

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   K71-9 (IG1) - Body ground	Ignition switch ON	11 to 14 V
   K71-4 (BAT) - Body ground	Always	11 to 14 V

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

Result: 

OK 

See step  3

1. Turn the ignition switch off.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   *a	Front view of wire harness connector (to Steering Angle Sensor)

2. Measure the resistance according to the value(s) in the table below.
   NOTE:

   Before measuring the resistance of the steering angle sensor, turn the ignition switch off and leave the vehicle for 1 minute or more without operating the key or switches, or opening or closing the doors.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   K71-6 (ESS) - Body ground	1 minute after ignition switch off	Below 1 Ω

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE STEERING ANGLE SENSOR. Refer to  REMOVAL [06/2017 - 10/2020] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR (GROUND CIRCUIT)