DTC C1784/84: Steering Sensor Signal Malfunction: Procedure

1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
2. Perform a road test.
3. Check if DTCs C1784/84 and U0126/71 are output. Refer to DTC CHECK / CLEAR .
   RESULT
   
   

   Condition	Proceed to
   DTC is not output or only DTC 1784/84 is output	A
   DTCs 1784/84 and U0126/71 are output	B

B → See step   5 

A: Go to next step 

1. Check for steering angle sensor malfunction DTCs. Refer to DTC CHECK / CLEAR .
   RESULT
   
   

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

B → See step   6 

A: Go to next step 

1. Disconnect the G21 steering angle sensor connector.
2. Measure the voltage and resistance according to the value(s) in the table below.
   Fig 1: Identifying G21 Steering Angle Sensor Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Standard Voltage

   Tester Connection	Switch Condition	Specified Condition
   G21-5 (IG) - Body ground	Engine switch on (IG)	11 to 14 V
   G21-6 (BAT) - Body ground	Always	11 to 14 V

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G21-2 (ESS) - Body ground	Always	Below 1 Ω

   TEXT IN ILLUSTRATION
   
   

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

3. Check that the steering angle sensor connector is not deformed or corroded.

   OK

   No deformation or corrosion.

   HINT: 

   If the steering angle sensor connector is defective, replace the spiral cable sub-assembly.

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Turn the engine switch off.
2. Connect the Techstream to the DLC3.
3. Turn the engine switch on (IG).
4. Turn the Techstream on.
5. Enter the following menus: Chassis / Air suspension / Data List.
   AIR SUSPENSION
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   Steering Angle	Steering angle/ Min.: -49152.0 deg Max.: 49150.5 deg	Actual steering angle Steering wheel turned left: reading increases Steering wheel turned right: reading decreases	-

   OK

   Steering wheel turning angle value changes when steering wheel is turned.

NG → See step   7 

OK → See step   8