Why is the adaptive cruise control not functioning in my 2020 Toyota Highlander?

Toyota Highlander Fourth Generation (2020-present)

Error Codes

medium

Difficulty

medium

Severity

3 min read

567 words

Problem Statement

Diagnose and troubleshoot the adaptive cruise control system in your 2020 Toyota Highlander with our step-by-step guide.

Affected Component

adaptive cruise control system

Symptoms

•Cruise Control Indicator does not illuminate
•Inability to Set Speed
•Warning Messages displayed on the instrument panel
•Sensor Obstruction

Diagnostic Steps

1
Check for visible obstructions on the front grille
2
Use an OBD-II scanner to check for diagnostic trouble codes
3
Ensure the cruise control system is enabled in vehicle settings
4
Check if the front radar sensor is properly aligned and calibrated
5
Use a multimeter to check the battery voltage

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
•Screwdrivers (Phillips and flathead)
•Torx socket set
•Cleaning supplies (microfiber cloth, isopropyl alcohol)
•Torque wrench

Related Faults

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Solution

Problem Diagnosis: Adaptive Cruise Control Not Functioning in 2020 Toyota Highlander

Tools Required

OBD-II Scanner
Multimeter
Screwdrivers (Phillips and flathead)
Torx socket set
Cleaning supplies (microfiber cloth, isopropyl alcohol)
Torque wrench (if sensor reinstallation is required)

Repair Instructions

Step 1: Visual Inspection

Inspect the Front Radar Sensor:
- Locate the radar sensor behind the front grille.
- Clean the sensor with a microfiber cloth and isopropyl alcohol if it appears dirty or obstructed by debris.
Inspect the Windshield Camera:
- Check the area around the windshield for dirt, bugs, or ice that might obstruct the camera’s view.

Step 2: Check for Fault Codes

Connect OBD-II Scanner:
- Plug the scanner into the OBD-II port located under the dashboard.
- Turn on the ignition (without starting the engine) and navigate to the diagnostic menu.
- Read any stored trouble codes related to ACC and note them for further action.

Step 3: System Status Check

Check Vehicle Settings:
- Access the vehicle’s onboard settings through the infotainment system and ensure ACC is enabled.
- Confirm that the vehicle is in a favorable condition for cruise control (engine running, speed above 25 mph, etc.).

Step 4: Sensor Calibration

Check Sensor Alignment:
- If misalignment is suspected (e.g., due to previous bodywork), the radar sensor may need recalibration.
- Refer to the service manual for specific calibration procedures for the radar system.

Step 5: Battery Voltage Check

Measure Battery Voltage:
- Set the multimeter to DC voltage and measure the battery voltage. It should be around 12.6 volts or higher when the engine is off.
- If the voltage is low, charge or replace the battery.

Conclusion

After performing these diagnostic steps and repairs, test the adaptive cruise control system by driving at a safe speed and attempting to engage the system. If the issue persists, further diagnostics may be needed, and it is advisable to consult a certified Toyota technician or service center for advanced troubleshooting or repairs.