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What are the common issues with the adaptive cruise control feature in the 2021 Toyota Highlander? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/What are the common issues with the adaptive cruise control feature in the 2021 Toyota Highlander?

What are the common issues with the adaptive cruise control feature in the 2021 Toyota Highlander?

Toyota Highlander Fourth Generation (2020-present)

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

Problem Statement

Explore common issues with the adaptive cruise control feature in the 2021 Toyota Highlander, including symptoms, diagnostic steps, and repair instructions.

Affected Component
Adaptive Cruise Control System

Symptoms

  • •Adaptive Cruise Control Not Engaging
  • •Erratic Speed Control
  • •Warning Lights
  • •Inconsistent Distance Maintenance
  • •System Deactivation

Diagnostic Steps

  1. 1
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  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
  • •Torque Wrench
  • •Screwdrivers (Phillips and Flathead)
  • •Multimeter
  • •Cleaning Supplies

Additional Information

Affected Component
Adaptive Cruise Control System
Difficulty
medium
Severity
medium
Tools Required
5 items

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Common Issues with Adaptive Cruise Control in the 2021 Toyota Highlander

Adaptive Cruise Control (ACC) is a convenient feature that helps maintain a set speed while automatically adjusting to the speed of the vehicle ahead. However, some owners of the 2021 Toyota Highlander may experience issues with this system. Below are some common symptoms, diagnostic steps, tools required, and repair instructions.

Common Symptoms

  1. Adaptive Cruise Control Not Engaging

    • The system fails to activate when the cruise control button is pressed.

  2. Erratic Speed Control

    • The vehicle accelerates or decelerates unexpectedly while in ACC mode.

  3. Warning Lights

    • Dashboard indicators such as the cruise control light or a warning message appear.

  4. Inconsistent Distance Maintenance

    • The system does not maintain a consistent distance from the vehicle ahead.

  5. System Deactivation

    • The ACC disengages unexpectedly, requiring manual reactivation.
Tools Required
  • OBD-II Scanner
  • Torque Wrench
  • Screwdrivers (Phillips and Flathead)
  • Multimeter (for checking battery voltage)
  • Cleaning Supplies (for sensor cleaning)
Repair Instructions

1. Engagement Issues

  • Step 1: Ensure that the vehicle is in the proper operating mode (not in manual mode).
  • Step 2: Press the cruise control button on the steering wheel. You should see the cruise control icon illuminate.
  • Step 3: If it still doesn’t engage, use the OBD-II scanner to check for DTCs and troubleshoot based on the codes provided.

2. Erratic Speed Control

  • Step 1: If the speed fluctuates, check wheel speed sensors as they provide data to the ACC system.
  • Step 2: Inspect the brake pedal switch. If it’s faulty, the system may disengage or misinterpret vehicle speed.
  • Step 3: Check for software updates. Sometimes, manufacturers release patches to fix bugs.

3. Warning Lights

  • Step 1: Retrieve and document any DTCs using the OBD-II scanner.
  • Step 2: Refer to the service manual for specific troubleshooting steps based on the error codes.
  • Step 3: Clear the codes and test the system to see if the issue is resolved.

4. Inconsistent Distance Maintenance

  • Step 1: Check the radar sensor’s cleanliness. Clean the sensor lens with a soft cloth and appropriate cleaner.
  • Step 2: Verify the sensor’s alignment. If misaligned, adjust as per the manufacturer's specifications.
  • Step 3: Conduct a road test to see if the behavior improves.

5. System Deactivation

  • Step 1: Investigate the brake pedal switch and ensure it’s functioning correctly. Replace if necessary.
  • Step 2: Check the vehicle's battery voltage. A multimeter can be used to confirm that it’s within the proper range (12.4V - 12.7V).
  • Step 3: If the problem persists, consult a Toyota dealership for advanced diagnostics.
Conclusion

If these steps do not solve the adaptive cruise control issues in your 2021 Toyota Highlander, it may be necessary to consult a professional technician or visit a Toyota dealership for further diagnosis and repair. Advanced electronic issues may require specialized tools and knowledge beyond standard home repair capabilities.