Inspection Procedure

Fig 1: Identifying A41 Steering Control ECU Connector And L21 Steering Angle Sensor Connector

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Disconnect the A41 steering control ECU connector.
2. Disconnect the L21 steering angle sensor connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance 

   RESISTANCE SPECIFICATION
   
   

   Tester Connection	Condition	Specified Condition
   A41-10 (SS1-) - L21-7 (SS1-)	Always	Below 1 Ω
   A41-19 (SS1+) - L21-8 (SS1+)	Always	Below 1 Ω
   A41-19 (SS1+) - Body ground	Always	10 kΩ or higher
   A41-10 (SS1-) - Body ground	Always	10 kΩ or higher
   A41-19 (SS1+) - A41-10 (SS1-)	Always	10 kΩ or higher

NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the A41 steering control ECU connector.

   HINT:

   The resistance must be measured after the steering angle sensor connector is connected.

2. Adjust the shift lever to neutral.
3. Jack up the vehicle.
4. Turn the engine switch on (IG).
5. Check the waveform of the steering angle sensor using an oscilloscope.

   Standard Voltage 

   VOLTAGE SPECIFICATION
   
   

   Tester Connection	Switch Condition	Specified Condition
   A41-19 (SS1+) - A41-10 (SS1-)	Engine switch on (IG), rotate steering wheel slowly	Pulse generation (0 to 5 V)

   Fig 2: Identifying A41 Steering Control ECU Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   HINT:

   The output voltage should fluctuate up and down similarly to the diagram when the wheel is turned slowly.

NG: REPLACE STEERING ANGLE SENSOR  (See REMOVAL )

OK: REPLACE STEERING CONTROL ECU  (See REMOVAL  )