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Home >> Lexus >> 2022 >> UX 250h Base >> Repair and Diagnosis >> Restraints >> Restraints Control Systems >> Pre-Collision (Diagnostics - Introduction) >> Pre-Collision System >> Problem Symptoms Table [07/2022 - ] >> Problem Symptoms Table [07/2022 - ]

Problem Symptoms Table [07/2022 - ]

NOTE:

When replacing the combination meter assembly, always replace it with a new one. If a combination meter assembly which was installed to another vehicle is used, the information stored in it will not match the information from the vehicle and a DTC may be stored.

HINT: 

PRE-COLLISION SYSTEM

Symptom Suspected Area Link
"Pre-Collision System Radar In Self Calibration Unavailable See Owner's Manual" is displayed Vehicle control history: 
  • X2025: Front Radar Sensor Temporary Unavailable (Horizontal Direction Optical Axis Misalignment)
  1. Check the vehicle control history of the pre-collision system

    Refer to VEHICLE CONTROL HISTORY [07/2022 - ]

  2. If the vehicle control history of the pre-collision system is stored, check the installation condition of the millimeter wave radar sensor assembly

    Refer to INSTALLATION [07/2022 - ]

  3. Perform millimeter wave radar sensor assembly beam axis alignment.

    HINT: 

    Beam axis alignment of the millimeter wave radar sensor assembly can be performed using either Triangle Target, Flat Surface Target or Driving Adjustment.

    Triangle Target: Refer to TARGET ADJUSTMENT(TRIANGLE TARGET) [07/2022 - ]

    Flat Surface Target: Refer to TARGET ADJUSTMENT(FLAT SURFACE TARGET) [07/2022 - ]

    Driving Adjustment: Refer to DRIVING ADJUSTMENT [07/2022 - ]

Cause: 
  • X2025: Stores the history when the millimeter wave radar sensor assembly judges that the millimeter wave radar sensor assembly horizontal axis is misaligned
"Pre-Collision System Out of Temperature Range Unavailable See Owner's Manual" is displayed Vehicle control history: 
  • X2027: Front Radar Sensor Outside Guaranteed Operating Temperature
  1. Check the vehicle control history of the front radar sensor system

    Refer to DATA LIST / ACTIVE TEST [07/2022 - ]

  2. Using the Techstream, check the "Millimeter-wave Circuit Temperature Protection" for the front radar sensor on the Data List

    Refer to DATA LIST / ACTIVE TEST [07/2022 - ] 

  3. If the "Millimeter-wave Circuit Temperature Protection" is ON, cool or warm the area surrounding the millimeter wave radar sensor assembly
Cause: 
  • The millimeter wave radar sensor assembly is in one of the following conditions
    • When the ambient temperature of the millimeter wave radar sensor is -30°C (-22°F) or less, such as when the vehicle is left alone in an extremely cold environment
    • When the ambient temperature of the millimeter wave radar sensor is 70°C (158°F) or higher, such as when the vehicle is left alone in an extremely hot environment
"Pre-Collision System Unavailable See Owner's Manual" is displayed Vehicle control history: 
  • X2028: Front Radar Sensor Outside Guaranteed Operating Voltage
  1. Check the vehicle control history of the front radar sensor system

    Refer to VEHICLE CONTROL HISTORY [07/2022 - ]

  2. After clearing the vehicle control history, drive at a vehicle speed of 5 km/h (3 mph) or more and check whether the vehicle control history is output
  3. If the vehicle control history is output, check if the voltage of the millimeter wave radar sensor assembly ECU terminal layout (IGB to SGND) is within the specified range

    Refer to TERMINALS OF ECU [10/2018 - ]

Cause: 
  • The millimeter wave radar sensor assembly is in one of the following conditions
    • When the input voltage is approximately 8 V or less, immediately after starting the hybrid control system
    • When the input voltage is approximately 16 V or higher, immediately after starting the hybrid control system
"Pre-Collision System Radar Sensor Blocked Unavailable Clean Radar Sensor" is displayed Vehicle control history: 
  • X2026: Front Radar Sensor Dirt
  1. Check the vehicle control history of the front radar sensor system

    Refer to VEHICLE CONTROL HISTORY [07/2022 - ]

  2. Check for the following
    • Whether a cover other than the dedicated millimeter wave radar cover is being used
    • Whether the area surrounding the radar and emblem is dirty
    • Whether accessories that may interfere with the radar waves such as a bull bar is installed
    • Whether any paint, coating or stickers are applied to the dedicated cover
    • Whether any foreign matter is stuck between the radar and emblem
Cause: 
  • When foreign matter or dirt is attached to the millimeter wave radar sensor assembly
"VSC Turned Off Pre-Collision Brake System Unavailable" is displayed Check whether VSC is off -
Electronically controlled brake system Refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2018 - ]
Pre-collision system cannot be canceled (PCS warning light does not illuminate) Combination meter assembly (check if indicator illuminates using Active Test) Refer to DATA LIST / ACTIVE TEST [07/2022 - ]
Meter / gauge system Refer to HOW TO PROCEED WITH TROUBLESHOOTING [07/2022 - ]
Steering pad switch assembly Refer to INSPECTION [10/2018 - ]
Combination meter assembly Refer to REMOVAL [07/2022 - ]