DTC C1595/55: Lost Communication with Steering Angle Sensor Module; DTC C15C4/68: Steering Angle Signal (Test Mode DTC): Procedure

1. Check for DTCs in the CAN communication system. Refer to DIAGNOSIS SYSTEM .
   RESULT
   
   

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

B → GO TO THE APPROPRIATE CAN COMMUNICATION SERVICE INFORMATION. Refer to HOW TO PROCEED WITH TROUBLESHOOTING  . 

A: Go to next step 

1. Check that a steering angle sensor with the specified part number is installed.

   Standard

   A steering angle sensor with the specified part number (89245-30070) is installed.

NG → REPLACE STEERING ANGLE SENSOR 

OK: Go to next step 

1. Turn the power switch OFF.
   Fig 1: Checking Wire Harness (Steering Control ECU - Steering Angle Sensor)

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Disconnect the K70 steering control ECU connector.
3. Disconnect the K19 steering angle sensor connector.
4. Measure the resistance of the wire harness side connectors.

   Standard resistance

   Tester Connection	Specified Condition
   K70-10 (SS1-) - K19-7 (SS1-)	Below 1 Ω
   K70-19 (SS1+) - K19-8 (SS1+)	Below 1 Ω
   K70-19 (SS1+) - Body ground	10 kΩ or higher
   K70-10 (SS1-) - Body ground	10 kΩ or higher
   K70-19 (SS1+) - K70-10 (SS1-)	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Disconnect the K70 steering control ECU connector.
   Fig 2: Identifying K70 Steering Control ECU Connector With Waveform Graph

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   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 power switch ON (IG).
5. Check the waveform of the steering angle sensor using an oscilloscope.

   Standard voltage

   Tester Connection	Condition	Specified Condition
   K70-19 (SS1+) - K70-10 (SS1-)	Power switch ON (IG), rotate steering wheel slowly	Pulse generation (0 ←→ 5 V)

   HINT: 

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

NG → REPLACE STEERING ANGLE SENSOR 

OK → REPLACE STEERING CONTROL ECU