LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> Restraints >> Restraints Control Systems >> Pre-Collision System - Diagnostics - Introduction >> Pre-Collision System >> How To Proceed With Troubleshooting [12/2019 - 09/2020] >> Procedure
April 5, 2026: LEMON Manuals is launched! Read the announcement.

How To Proceed With Troubleshooting [12/2019 - 09/2020]: Procedure

  1. VEHICLE BROUGHT TO WORKSHOP 

    Result

    Proceed to
    NEXT

    Result: 

    NEXT 

    See step  2

  2. PRE-CHECK 
    1. for HV Model
      1. Measure the auxiliary battery voltage with the ignition switch off.

        Standard Voltage

        11 to 14 V

        If the voltage is below 11 V, recharge or replace the auxiliary battery before proceeding to the next step.

    2. for Gasoline Model
      1. Measure the auxiliary battery voltage.

        Standard Voltage

        11 to 14 V

        If the voltage is below 11 V, recharge or replace the auxiliary battery before proceeding to the next step.

    3. Check the fuses and relays.
    4. Check the connector connections and terminals to make sure that there are no abnormalities such as loose connections, deformation, etc.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  3

  3. INSPECT MULTI-INFORMATION DISPLAY 
    1. Check if a pre-collision system warning message is displayed on the multi-information display in the combination meter assembly.

      HINT: 

      If more than one message is displayed, perform each inspection in the order listed in the table.

      Result

      Result Proceed to
      "VSC Turned OFF Pre-Collision Brake System Unavailable" is displayed A
      "Pre-Collision System Malfunction Visit Your Dealer" is displayed B
      "Pre-Collision System Unavailable Clean Sensor" is displayed C
      Any of the following messages is displayed:
      • "Pre-Collision System Unavailable"
      • "Pre-Collision System Unavailable Clean Sensor"
      • "Front Camera Unavailable"
      • "Front Camera Unavailable See Owner's Manual"
      		 D
      Warning message is not displayed E

    Result: 

    A 

    GO TO PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [12/2019 - 09/2020]  

    Result: 

    C 

    See step  9

    Result: 

    D 

    See step  6

    Result: 

    E 

    See step  13

    Result: 

    B 

    See step  4

  4. CHECK CAN COMMUNICATION SYSTEM* 
    1. Using the GTS, check if the CAN communication system is functioning normally.

      HINT: 

      Refer to CAN Bus Check in CAN Communication System.

      for HV Model: Refer to DIAGNOSIS SYSTEM [12/2019 - 09/2020]

      for Gasoline Model: Refer to DIAGNOSIS SYSTEM [12/2019 - 09/2020]

      OK

      CAN communication system is functioning normally.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    GO TO CAN COMMUNICATION SYSTEM 

    for HV Model: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 10/2021]

    for Gasoline Model: Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 10/2022]

    Result: 

    OK 

    See step  5

  5. CHECK FOR DTCs* 
    1. Using the GTS, check for DTCs.

      Body Electrical > Pre-Collision System > Trouble Codes 

    2. Make a note of the output DTCs.

      Result

      Result Proceed to
      DTCs are not output A
      DTC C1425-71 is output B
      DTCs other than C1425-71 are output C

    Result: 

    B 

    GO TO DTC CHART (C1425-71). Refer to  DTC C1425-71: Stop Light Relay Actuator Stuck [12/2019 - ] 

    Result: 

    C 

    See step  8

    Result: 

    A 

    See step  6

  6. CHECK VEHICLE CONTROL HISTORY* 
    1. Using the GTS, check for Vehicle Control History (RoB).

      Body Electrical > Pre-Collision System > Utility 

      Tester Display
      Vehicle Control History (RoB)
    2. Record any output Vehicle Control History (RoB).

      Result

      Result Proceed to
      Vehicle Control History (RoB) codes are not output A
      Vehicle Control History (RoB) code X2013, X2015, X2022, X2024, X2025, X2026 or X2028 is output B
      Vehicle Control History (RoB) codes other than X2013, X2015, X2022, X2024, X2025, X2026 and X2028 are output C

    Result: 

    A 

    GO TO SYMPTOM SIMULATION. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

    Result: 

    B 

    GO TO VEHICLE CONTROL HISTORY (X2013, X2015, X2022, X2024, X2025, X2026 or X2028). Refer to  VEHICLE CONTROL HISTORY [12/2019 - 09/2020] 

    Result: 

    C 

    See step  7

  7. RECONFIRM VEHICLE CONTROL HISTORY* 
    1. Using the GTS, clear the Vehicle Control History (RoB).

      Body Electrical > Pre-Collision System > Utility 

      Tester Display
      Vehicle Control History (RoB)
    2. Using the GTS, check for Vehicle Control History (RoB).

      Body Electrical > Pre-Collision System > Utility 

      Tester Display
      Vehicle Control History (RoB)

      Result

      Result Proceed to
      Vehicle Control History codes (RoB) are not output A
      Vehicle Control History codes (RoB) are output B

    Result: 

    A 

    GO TO SYMPTOM SIMULATION. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

    Result: 

    B 

    GO TO VEHICLE CONTROL HISTORY. Refer to  VEHICLE CONTROL HISTORY [12/2019 - 09/2020] 

  8. RECONFIRM DTC OUTPUT* 
    1. Using the GTS, clear the DTCs.

      Body Electrical > Pre-Collision System > Clear DTCs 

    2. Reproduce the vehicle conditions that were present when the DTCs that were noted were stored.

      HINT: 

      Refer to each corresponding DTC for details on the detection conditions.

      Refer to DIAGNOSTIC TROUBLE CODE CHART [12/2019 - 09/2020] 

    3. Using the GTS, check for DTCs.

      Body Electrical > Pre-Collision System > Trouble Codes 

      Result

      Result Proceed to
      DTCs are not output A
      DTCs are output B

    Result: 

    A 

    GO TO SYMPTOM SIMULATION. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

    Result: 

    B 

    GO TO DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [12/2019 - 09/2020]  

  9. INSPECT MILLIMETER WAVE RADAR SENSOR ASSEMBLY 
    1. Check that there is no foreign matter such as dirt on or around the millimeter wave radar sensor assembly.

      HINT: 

      • A cover other than the dedicated radar sensor cover is not installed.
      • There is no dirt on the radar sensor cover or millimeter wave radar sensor assembly.
      • An accessory, such as bull bars, a grille guard, etc., which interferes with millimeter radio waves is not installed.
      • There is no sticker or coating applied to the dedicated radar sensor cover.
      • There is no foreign matter between the radar sensor cover and millimeter wave radar sensor assembly.
    2. If a problem is found, correct the problem as necessary.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  10

  10. INSPECT MULTI-INFORMATION DISPLAY 
    NOTE:

    Before checking if the pre-collision system warning message is displayed on the multi-information, turn the ignition switch off then to ON.

    1. Turn the ignition switch off.
    2. Turn the ignition switch to ON.
    3. Check if "Pre-Collision System Unavailable Clean Sensor" is displayed on the multi-information display.

      Result

      Result Proceed to
      Not displayed A
      Displayed B

    Result: 

    B 

    ADJUST MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  ADJUSTMENT [12/2019 - 09/2020] 

    Result: 

    A 

    See step  11

  11. READ VALUE USING GTS 
    1. Read the Data List according to the display on the GTS.

      Body Electrical > Front Radar Sensor > Data List 

      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      On-Line Calibration Angle (Horizontal) Calibrated angle value (horizontal) Min.: -12.8 deg, Max.: 12.7 deg Learned value -

      Body Electrical > Front Radar Sensor > Data List 

      Tester Display
      On-Line Calibration Angle (Horizontal)

      OK

      The displayed value is between -0.5 and 0.5 degrees.

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    ADJUST MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  ADJUSTMENT [12/2019 - 09/2020] 

    Result: 

    OK 

    See step  12

  12. EXPLAIN TO THE CUSTOMER 
    1. Explain to the customer that "Pre-Collision System Unavailable Clean Sensor" was temporarily displayed on the multi-information display due to foreign matter such as dirt on or around the millimeter wave radar sensor assembly.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    END 

  13. PROBLEM SYMPTOMS TABLE 
    1. Refer to Problem Symptoms Table for the pre-collision system.

      Refer to PROBLEM SYMPTOMS TABLE [12/2019 - 09/2020] 

      Result

      Result Proceed to
      Problem symptoms are not listed in the Problem Symptoms Table. A
      Problem symptoms are listed in the Problem Symptoms Table. B

    Result: 

    B 

    GO TO PROBLEM SYMPTOMS TABLE. Refer to  PROBLEM SYMPTOMS TABLE [12/2019 - 09/2020]  

    Result: 

    A 

    See step  14

  14. INSPECT WARNING LIGHT 
    1. Check the condition of the warning lights.

      Result

      Result Proceed to
      The PCS warning light is not illuminated A
      Only the PCS warning light is illuminated B

    Result: 

    B 

    GO TO VEHICLE CONTROL HISTORY (X2015). Refer to  VEHICLE CONTROL HISTORY [12/2019 - 09/2020] 

    Result: 

    A 

    See step  15

  15. CHECK FOR DTCs* (Confirmed) 
    1. Using the GTS, check for DTCs (Confirmed).

      Body Electrical > Pre-Collision System > Trouble Codes 

    2. Make a note of the output DTCs (Confirmed).

      Result

      Result Proceed to
      DTCs (Confirmed) are not output A
      DTCs (Confirmed) are output B

    Result: 

    B 

    See step  19

    Result: 

    A 

    See step  16

  16. CHECK VEHICLE CONTROL HISTORY* 
    1. Using the GTS, check for Vehicle Control History (RoB).

      Body Electrical > Pre-Collision System > Utility 

      Tester Display
      Vehicle Control History (RoB)
    2. Record any output Vehicle Control History (RoB).

      Result

      Result Proceed to
      Vehicle Control History codes (RoB) are not output A
      Vehicle Control History codes (RoB) are output B

    Result: 

    B 

    GO TO VEHICLE CONTROL HISTORY 

    Refer to VEHICLE CONTROL HISTORY [12/2019 - 09/2020]

    HINT: 

    By using information obtained from the customer problem analysis and vehicle control history such as time of detection, trip number, etc., it may be possible to determine the cause of the malfunction.

    Result: 

    A 

    See step  17

  17. CHECK CONDITIONS WHEN PRE-COLLISION SYSTEM DID NOT OPERATE 
    1. Check if the exception conditions for the pre-collision system were met.

      Refer to PRECAUTION [12/2019 - 09/2020] 

      Result

      Result Proceed to
      The exception conditions were not met. A
      The exception conditions were met. B

    Result: 

    B 

    END (The pre-collision system operated accordingly with the operation and prohibition conditions.) 

    Result: 

    A 

    See step  18

  18. INSPECT MILLIMETER WAVE RADAR SENSOR ASSEMBLY (BEAM AXIS MISALIGNMENT READING)* 
    NOTE:

    Before checking for millimeter wave radar sensor beam axis misalignment, make sure that the radiator grille and front bumper are correctly installed and have not been damaged or modified.

    1. Adjust the reflector height.

      Refer to ADJUSTMENT [12/2019 - 09/2020]

    2. Place the reflector.

      Refer to ADJUSTMENT [12/2019 - 09/2020]

    3. Connect the GTS to the DLC3.
    4. Turn the ignition switch to ON.
    5. Turn the GTS on.
    6. Enter the following menus: Body Electrical / Front Radar Sensor / Utility / Front Beam Axis Misalignment Reading.

      Body Electrical > Front Radar Sensor > Utility 

      Tester Display
      Front Beam Axis Misalignment Reading
    7. Check the amount of misalignment.

      Standard

      Vertical Direction -5 to 5 deg.
      Horizontal Direction -0.6 to 0.6 deg.

      HINT: 

      The millimeter wave radar sensor assembly automatically calibrates the beam axis while the vehicle is being driven. The specified values apply to the automatic calibration only and do not apply during manual beam axis adjustment of the millimeter wave radar sensor assembly.

      Result

      Result Proceed to
      The beam axis values are within specification. A
      The beam axis values are not within specification. B

    Result: 

    A 

    GO TO SYMPTOM SIMULATION. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - ] 

    Result: 

    B 

    ADJUST MILLIMETER WAVE RADAR SENSOR ASSEMBLY. Refer to  ADJUSTMENT [12/2019 - 09/2020] 

  19. GO TO DTC CHART 
    1. Refer to each corresponding DTC (Confirmed) for details on the detection conditions.

      Refer to DIAGNOSTIC TROUBLE CODE CHART [12/2019 - 09/2020] 

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    END 

scientia non olet · About LEMON Manuals