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Home › Lexus › 2008 › LS 460L › Repair and Diagnosis › Suspension › Suspension Control Systems › Air Suspension System › DTC C1784: Steering Angle Sensor Communication Error › Inspection Procedure

Inspection Procedure

NOTE:
  • Before performing troubleshooting, inspect the connectors of related circuits.
  • If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 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) 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 and U0126 are output.

    Result 

    RESULT TABLE

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

    B: GO TO  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 

    RESULT TABLE

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

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

    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 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

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

      Standard resistance 

      TESTER CONNECTION SPECIFIED CONDITION TABLE

      Tester Connection Condition Specified Condition
      L21-2 (ESS) - Body ground Always Below 1 Ω
      Fig 1: Identifying L21 Sensor Connector
      G05848065Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    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 Techstream to the DLC3.
    3. Turn the engine switch on (IG) and the Techstream on.
    4. Enter the following menus: Chassis / Air suspension / Data List.
    5. Check the values by referring to the table below.

Air suspension 

DIAGNOSTIC NOTE TABLE

Tester Display Measurement Item/Range Normal Condition 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  )

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