What are the common issues with the adaptive cruise control in the 2020 Toyota Highlander?

Toyota Highlander Fourth Generation (2020-present)

Error Codes

medium

Difficulty

medium

Severity

3 min read

600 words

Problem Statement

Explore common issues with the adaptive cruise control system in the 2020 Toyota Highlander, including symptoms, diagnostic steps, and repair instructions.

Affected Component

adaptive cruise control system

Symptoms

•Inconsistent Speed Control
•System Not Engaging
•False Alerts
•Camera or Radar Errors

Diagnostic Steps

1
Visual Inspection
2
Check for Diagnostic Trouble Codes (DTCs)
3
Perform Operational Tests

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 (flathead and Phillips)
•Ratchet and socket set
•Cleaning supplies (microfiber cloth, cleaning solution)
•Multimeter

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Solution

Common Issues with Adaptive Cruise Control in the 2020 Toyota Highlander

The adaptive cruise control (ACC) system in the 2020 Toyota Highlander, part of the fourth generation (XU70), is designed to enhance driving convenience and safety. However, it may encounter several common issues. Below, we detail the symptoms, diagnostic steps, tools required, and repair instructions for addressing these potential problems.

Common Symptoms of ACC Issues

Inconsistent Speed Control: The vehicle may not maintain a constant speed or may accelerate/decelerate unexpectedly.
System Not Engaging: The adaptive cruise control feature may not activate when the button is pressed.
False Alerts: The system may issue warnings or deactivate due to perceived obstacles that aren’t present.
Camera or Radar Errors: Alerts indicating a malfunction with the radar or camera sensors, often accompanied by warning lights on the dashboard.

1. Visual Inspection

Check Sensor Alignment: Inspect the front radar sensor and camera for any obstructions (e.g., dirt, ice, or debris). The sensor is usually located behind the front grille.
Look for Damage: Examine the sensor housing and wiring for any signs of damage or disconnection.

2. Check for Diagnostic Trouble Codes (DTCs)

Tools Required: OBD-II scanner
Procedure:
1. Connect the OBD-II scanner to the vehicle’s diagnostic port (usually located under the driver’s side dashboard).
2. Turn on the ignition and scan for any DTCs related to the ACC system.
3. Document any codes found and refer to the service manual for specific troubleshooting based on the codes.

3. Perform Operational Tests

Test the ACC Functionality: On a clear, open road, attempt to engage the adaptive cruise control.
Observe Behavior: Note if the system maintains speed, if it disengages suddenly, or if it fails to engage at all.

Tools Required

OBD-II scanner
Torque wrench
Screwdrivers (flathead and Phillips)
Ratchet and socket set
Cleaning supplies (microfiber cloth, cleaning solution)
Multimeter (if electrical issues are suspected)

Repair Instructions

1. Cleaning the Sensors

If visual inspection reveals dirt or debris:
1. Use a microfiber cloth and a mild cleaning solution to gently clean the radar sensor and camera.
2. Ensure the area around the sensors is free from obstructions.

2. Re-aligning the Radar Sensor

If the radar sensor is misaligned:
1. Loosen the mounting bolts using a ratchet and socket.
2. Adjust the sensor position as necessary to ensure it is facing directly forward.
3. Tighten the bolts to the manufacturer’s specified torque.

3. Clearing DTCs

If DTCs were present:
1. After performing necessary repairs, use the OBD-II scanner to clear the codes.
2. Recheck for any codes after clearing to confirm the issue has been resolved.

4. Wiring Inspection and Repair

If wiring issues are suspected:
1. Inspect the wiring harness leading to the radar sensor for any frays or disconnections.
2. Use a multimeter to check for continuity.
3. Repair any damaged wiring by soldering or using appropriate connectors.

5. System Reset (if applicable)

After repairs, it may be beneficial to reset the ACC system:
1. Disconnect the vehicle battery for about 10 minutes.
2. Reconnect the battery and perform a test drive to check ACC functionality.

Final Checks

After completing the repairs, conduct a thorough test drive to ensure that the adaptive cruise control system is functioning correctly. Monitor for any warning lights and confirm that the system engages and maintains speed as intended. If issues persist, further diagnosis may be required, potentially involving dealer-level equipment or software updates.