FAULTBASE
Error CodesASKCars
© 2026 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
What are the common issues with the Toyota Safety Sense features in a 2021 Highlander? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/What are the common issues with the Toyota Safety Sense features in a 2021 Highlander?

What are the common issues with the Toyota Safety Sense features in a 2021 Highlander?

Toyota Highlander Fourth Generation (2020-present)

Error Codes
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
4 min read
677 words

Problem Statement

Explore common issues with Toyota Safety Sense features in the 2021 Highlander, including symptoms, diagnostic steps, and repair instructions.

Affected Component
Toyota Safety Sense

Symptoms

  • •Adaptive Cruise Control fails to engage
  • •ACC disengages unexpectedly during operation
  • •Frequent false alerts or warnings from Pre-Collision System
  • •PCS does not activate when it should
  • •Lane Departure Alert fails to detect lane markings
  • •LDA activates without crossing lane lines
  • •AHB does not switch on/off correctly
  • •AHB activates inappropriately in well-lit areas
  • •BSM indicator fails to illuminate when a vehicle is in the blind spot
  • •BSM alerts activate erratically

Diagnostic Steps

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

  • ✓Test the affected component to ensure it functions correctly
  • ✓Check for any error codes or warning lights
  • ✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • •OBD-II Scanner
  • •Multimeter
  • •Torque wrench
  • •Diagnostic software (Toyota Techstream or equivalent)
  • •Cleaning supplies (microfiber cloth, soft brush)
  • •Calibration tools (if necessary)

Additional Information

Affected Component
Toyota Safety Sense
Difficulty
medium
Severity
medium
Tools Required
6 items

Related Faults

Loading...

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation

Common Issues with Toyota Safety Sense Features in a 2021 Highlander

Toyota Safety Sense (TSS) is a suite of advanced safety features designed to enhance driver awareness and vehicle safety. For the 2021 Toyota Highlander, drivers may encounter several issues with these features. Below is a structured overview of common symptoms, diagnostic steps, tools required, and potential repair instructions.

Common Symptoms
  1. Adaptive Cruise Control (ACC) Malfunction

    • Adaptive Cruise Control fails to engage.
    • ACC disengages unexpectedly during operation.
  2. Pre-Collision System (PCS) Alerts

    • Frequent false alerts or warnings.
    • PCS does not activate when it should.
  3. Lane Departure Alert (LDA) Issues

    • Lane Departure Alert fails to detect lane markings.
    • LDA activates without crossing lane lines.
  4. Automatic High Beams (AHB) Problems

    • AHB does not switch on/off correctly.
    • AHB activates inappropriately in well-lit areas.
  5. Blind Spot Monitor (BSM) Malfunction

    • BSM indicator fails to illuminate when a vehicle is in the blind spot.
    • BSM alerts activate erratically.
Tools Required
  • OBD-II Scanner
  • Multimeter
  • Torque wrench
  • Diagnostic software (Toyota Techstream or equivalent)
  • Cleaning supplies (microfiber cloth, soft brush)
  • Calibration tools (if necessary)
Repair Instructions
1. Adaptive Cruise Control (ACC) Repair
  • Step 1: Check for DTCs related to ACC. Address any codes found.
  • Step 2: Inspect the radar sensor located in the front grille for obstructions or damage.
  • Step 3: Clean the sensor lens with a microfiber cloth.
  • Step 4: If necessary, recalibrate the radar sensor using Toyota Techstream.
  • Step 5: Test ACC functionality after repairs.
2. Pre-Collision System (PCS) Repair
  • Step 1: Clear any DTCs and test drive to see if the issues persist.
  • Step 2: Inspect the front camera and radar for cleanliness and alignment.
  • Step 3: Verify that the radar sensor is not blocked and recalibrate if needed.
  • Step 4: If false alerts continue, consult with a dealership for a software update.
3. Lane Departure Alert (LDA) Repair
  • Step 1: Inspect the front camera for dirt or damage.
  • Step 2: Clean the camera lens with a soft cloth.
  • Step 3: Check for proper calibration of the camera. Use Toyota Techstream to recalibrate if necessary.
  • Step 4: Test LDA functionality by driving on different roads with clear lane markings.
4. Automatic High Beams (AHB) Repair
  • Step 1: Inspect the front camera for obstructions.
  • Step 2: Check the settings in the vehicle’s menu to ensure AHB is activated.
  • Step 3: Clean the camera lens and recalibrate if necessary.
  • Step 4: Test the AHB system in varying light conditions to confirm functionality.
5. Blind Spot Monitor (BSM) Repair
  • Step 1: Inspect the side radar sensors for obstructions.
  • Step 2: Clean the sensors with a microfiber cloth.
  • Step 3: Check for DTCs related to the BSM system and address any found.
  • Step 4: If issues persist, recalibrate the sensors and test functionality.
Conclusion

By following these structured diagnostic steps and repair instructions, many common issues with the Toyota Safety Sense features in a 2021 Highlander can be effectively addressed. If problems persist despite these efforts, it may be necessary to consult a qualified Toyota technician or dealership for further diagnosis and repair.