LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2007 >> LS 460 >> Repair and Diagnosis >> Suspension >> Suspension Control Systems >> Suspension Control >> Air Suspension System >> DTC C1784 Steering Angle Sensor Communication Error >> Inspection Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Inspection Procedure

NOTE:
  • Before performing troubleshooting, inspect the connectors of related circuits.
  • If DTC C1782/82 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782/82 first (see DTC C1782 POWER SOURCE VOLTAGE MALFUNCTION  ).
  • Before replacing the suspension control ECU, perform all of the following again: 1) symptom simulation (see ELECTRONIC CIRCUIT INSPECTION PROCEDURE ); 2) DTC inspection; and 3) Intelligent tester or Techstream inspection (Data List or Active Test). If no malfunctions are found in other areas, replace the suspension control ECU.
  • If the suspension control ECU or height control sensor is replaced, the vehicle height offset calibration must be performed (see INITIALIZATION  ).
  1. CHECK DTC 
    1. Clear the DTC (see DTC CHECK / CLEAR  ).
    2. Perform a road test.
    3. Check for DTC (see DTC CHECK / CLEAR  ). Check if DTC C1784/ 84 and U0126/71 are output.

      Result 

      RESULT CHART

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

    B: GO TO CAN COMMUNICATION SYSTEM  (See CAN COMMUNICATION SYSTEM )

    A: GO TO NEXT STEP 

  2. CHECK DTC (BRAKE CONTROL SYSTEM) 
    1. Check for DTC (see DTC CHECK/CLEAR ). Check if DTC C1231/ 31 is output.

      Result 

      DTC (BRAKE CONTROL SYSTEM)

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

    B: GO TO BRAKE CONTROL SYSTEM  (See DIAGNOSTIC TROUBLE CODE CHART )

    A: GO TO NEXT STEP 

  3. CHECK STEERING ANGLE SENSOR (POWER SOURCE) 
    1. Disconnect the L21 sensor connector.
    2. Measure the voltage and resistance according to the value(s) in the table below.

      Standard voltage 

      STEERING ANGLE SENSOR (POWER SOURCE) VOLTAGE

      Tester Connection Condition Specified Condition
      L21-1 (IG)-Body ground Engine switch on (IG) 11 to 14 V
      Fig 1: Checking Steering Angle Sensor (Power Source)
      G04944170Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      Standard resistance 

      STEERING ANGLE SENSOR (POWER SOURCE) RESISTANCE

      Tester Connection Condition Specified Condition
      L21-2 (ESS) - Body ground Always Below 1 Ω
    3. Check that the steering angle sensor's connector is not deformed or corroded.

      OK: No deformation or corrosion. 

      HINT:

      If the steering angle sensor's connector is defective, replace the sensor.

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: GO TO NEXT STEP 

  4. CHECK STEERING ANGLE SENSOR (DATA LIST) 
    1. Turn the engine switch off.
    2. Connect the Intelligent tester or Techstream to the DLC3.
    3. Turn the engine switch on (IG) and turn the tester main switch on.
    4. Enter the following menus:
      1. Intelligent tester - Select: DIAGNOSIS / OBD/MOBD / CHASSIS / AIR SUSPENSION / DATA LIST /
      2. Techstream - Select: Chassis / Air suspension / Data List /
    5. Check the values by referring to the table below.
      1. Intelligent tester

        AIR SUSPENSION 

        INTELLIGENT TESTER - AIR SUSPENSION SPECIFICATION

        Tester Display Measurement Item/Range Normal Condn Diagnostic Note
        STEERING ANGLE Steering angle sensor reading/ min.: -49152°
        max.: 49150.5°        		 Actual steering angle
        Left turn: reading increases
        Right turn: reading decreases        		 -
      2. Techstream

        Air suspension 

        TECHSTREAM - AIR SUSPENSION SPECIFICATION

        Tester Display Measurement Item/Range Normal Condn Diagnostic Note
        Steering Angle Steering angle sensor reading/ min.: -49152°
        max.: 49150.5°        		 Actual steering angle
        Left turn: reading increases
        Right turn: reading decreases        		 -

        OK: Steering wheel turning angle value changes. 

    NG: REPLACE STEERING ANGLE SENSOR  (See REMOVAL )

    OK: REPLACE SUSPENSION CONTROL ECU (See  REMOVAL   ) 

scientia non olet · About LEMON Manuals