Inspection Procedure

HINT:

• When U0073/94, U0293/59, U0123/62, U0124/95, U0126/63, U0130/68 or U0131/67 is output together with C1231/31, inspect and repair the trouble areas indicated by U0073/94, U0123/62, U0124/95, U0126/63, U0130/68 or U0131/67 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 intelligent tester or Techstream and start from "CHECK DTC" when not using the intelligent tester or Techstream.

1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION) 
   1. Using the intelligent tester or Techstream, 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  ).
      1. Intelligent tester

         Skid control ECU: 

         SKID CONTROL ECU
         
         

         Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
         STEERING OPN	Steering angle sensor open detection / ERROR or NORMAL	ERROR: Momentary interruption NORMAL: Normal	-

      2. Techstream

         Skid control ECU: 

         SKID CONTROL ECU
         
         

         Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
         Steering Open	Steering angle sensor open detection / ERROR or NORMAL	ERROR: 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 DTC 
   1. Clear the DTC (see DTC CHECK/CLEAR  ).
   2. Turn the engine switch off.
   3. Turn the engine switch on (IG) again and check that no CAN communication system DTC is output.
   4. 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 

      RESULT REFERENCE
      
      

      Result	Proceed to
      No CAN communication system DTC and 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.	C

      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  (See HOW TO PROCEED WITH TROUBLESHOOTING )

   C: CHECK FOR CIRCUIT INDICATED BY OUTPUT CODE (See  DIAGNOSTIC TROUBLE CODE CHART   ) 

   A: GO TO NEXT STEP 

3. CHECK HARNESS AND CONNECTOR (STEERING ANGLE SENSOR - BODY GROUND) 
   Fig 1: Identifying L21 Sensor Connector
   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   1. Remove the steering wheel and the column cover lower.
   2. Disconnect the L21 sensor connector.
   3. Measure the voltage according to the value (s) in the table below.

      Standard voltage 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Switch Condition	Specified Condition
      L21-1 (IG)-Body ground	Engine switch on (IG)	11 to 14 V
      L21-3 (BAT)-Body ground	Always	11 to 14 V

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

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION
      
      

      Tester Connection	Switch Condition	Specified Condition
      L21-2 (ESS) - Body ground	Engine switch off	Below 1 Ω

      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, BAT OR ESS CIRCUIT) 

   OK: REPLACE STEERING ANGLE SENSOR (See  REMOVAL   ) 

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

      Result 

      RESULT REFERENCE
      
      

      Result	Proceed to
      DTC (C1231/31) is not output	A
      DTC (C1231/31) 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: GO TO NEXT STEP 

   END