Inspection Procedure

HINT:

• When U0121/94, U0123/62, U0124/95 or U0126/63 is output together with C1231/31, inspect and repair the trouble areas indicated by U0121/94, U0123/62, U0124/95 or U0126/63 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 step 1 when using Telecaster and start from step  2 when not using Telecaster.

1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION) 
   1. Using Telecaster, check for any momentary interruption in the wire harness and connectors between the skid control ECU and the steering angle sensor (See CHECK FOR INTERMITTENT PROBLEMS  ).

      DATA LIST: ABS / VSC / TRAC 

      DATA LIST
      
      

      Item	Measurement Item / Range (Display)	Normal Condition
      Steering Open	Steering sensor open detection / OPN DET or NORMAL	OPN DET: Momentary interruption NORMAL: Normal

      OK: 

      There are no momentary interruptions. 

      HINT:

      Perform the above inspection before removing the sensor and connector.

   NG:  Go to step  4

   OK: Go to next step 

2. CHECK STEERING ANGLE SENSOR 
   1. Clear the DTC.
   2. Turn the ignition switch off.
   3. Turn the ignition switch on (IG) again and check that no CAN communication system DTC is output.
   4. Start the engine.
   5. Drive the vehicle and turn the steering wheel to the right and left at the speed of 24 mph (35 km/h) and check that no speed sensor and yaw rate sensor DTCs are output.

      Result 

      RESULT CHART
      
      

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

      HINT:

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

   B : REPAIR CIRCUIT INDICATED BY OUTPUT CODE 

   A: Go to next step 

3. CHECK TERMINAL VOLTAGE (STEERING ANGLE SENSOR CONNECTOR) 
   1. Remove the steering wheel and the column lower cover.
   2. Disconnect the steering angle sensor connector.
   3. Turn the ignition switch on (IG).
   4. Measure the voltage according to the value(s) in the table below.

      Voltage 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Condition	Specified Condition
      D12-1 (IG) - D12-2 (ESS)	Ignition switch on (IG)	10 to 14 V

   5. Turn the ignition switch off.
   6. Measure the resistance according to the value(s) in the table below.

      Resistance 

      TESTER CONNECTION SPECIFIED CONDITION CHART
      
      

      Tester Connection	Specified Condition
      D12-2 (ESS) - Body ground	Below 1 Ω

      Fig 1: Identifying Steering Angle Sensor Connector Terminal

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      HINT:

      If troubleshooting has been carried out according to the PROBLEM SYMPTOMS TABLE, refer back to the table and proceed to the next step (See PROBLEM SYMPTOMS TABLE  ).

   NG: REPAIR OR REPLACE HARNESS OR CONNECTOR (IG, ESS CIRCUIT) 

   OK : REPLACE STEERING ANGLE SENSOR 

4. CHECK AND REPAIR HARNESS AND CONNECTOR (STEERING ANGLE SENSOR TO SKID CONTROL ECU) 
5. RECONFIRM DTC 
   1. Clear the DTC.
   2. Start the engine.
   3. Drive the vehicle and turn the steering wheel to the right and left at the speed of 24 mph (35 km/h) or more.
   4. Check that the same DTC is recorded.

      Result 

      RESULT CHART
      
      

      Result	Proceed to
      DTC is not output	A
      DTC is output	B

      HINT:

      If troubleshooting has been carried out according to the PROBLEM SYMPTOMS TABLE, refer back to the table and proceed to the next step (See PROBLEM SYMPTOMS TABLE  ).

   B:  Go to step  2

   A : END