DTC C1231/31: Steering Angle Sensor Circuit Malfunction: Procedure

1. Clear the DTCs, refer to DTC CHECK / CLEAR .
2. Turn the ignition switch off.
3. Turn the ignition switch to ON again and check that no CAN communication system DTC is output (w/ Smart Key System:, refer to DIAGNOSIS SYSTEM , w/o Smart Key System:, refer to DIAGNOSIS SYSTEM ).
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, refer to DTC CHECK / CLEAR .

   Result

   Result	Proceed to
   No CAN communication system, speed sensor, or yaw rate and acceleration sensor DTCs are output	A
   CAN communication system DTC is output (w/ Smart Key System)	B
   CAN communication system DTC is output (w/o Smart Key System)	C
   Speed sensor and/or yaw rate and acceleration sensor DTC is output	D

   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 speed sensor and yaw rate and acceleration sensor DTCs are output simultaneously, repair these 2 sensors and inspect the steering angle sensor.

B → See step   5 

C → See step   7 

D → See step   6 

A: Go to next step 

1. Turn the ignition switch off.
   Fig 1: Inspecting D14 Steering Angle Sensor (Power Source Terminal)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Remove the steering wheel and the column cover lower.
3. Make sure that there is no looseness at the locking part and the connecting part of the connector.
4. Disconnect the steering angle sensor connector.
5. Measure the voltage according to the value(s) in the table below.

   Standard Voltage

   Tester Connection	Condition	Specified Condition
   D14-4 (IG) - Body ground	Ignition switch ON	11 to 14 V
   D14-5 (BAT) - Body ground	Always	11 to 14 V

   TEXT IN ILLUSTRATION
   
   

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

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

OK: Go to next step 

1. Turn the ignition switch off.
   Fig 2: Inspecting D14 Steering Angle Sensor (Ground Terminal)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   D14-1 (ESS) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

   *1	Front view of wire harness connector (to 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 suspected area, refer to PROBLEM SYMPTOMS TABLE .

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

OK → See step   4