How do I troubleshoot a malfunctioning cruise control in my 2020 Highlander?

Toyota Highlander Fourth Generation (2020-present)

Error Codes

medium

Difficulty

medium

Severity

4 min read

769 words

Problem Statement

Learn how to troubleshoot and repair the cruise control system in your 2020 Toyota Highlander with step-by-step diagnostic and repair instructions.

Affected Component

Cruise Control System

Symptoms

•Cruise Control Not Engaging
•Cruise Control Disengages Unexpectedly
•Inconsistent Speed Maintenance
•Cruise Control Light Issues

Diagnostic Steps

1
Visual Inspection
2
Scan for Diagnostic Trouble Codes (DTCs)
3
Check Brake Pedal Position Switch
4
Test the Throttle Position Sensor (TPS)
5
Inspect Vehicle Speed Sensor (VSS)

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
•Screwdriver set
•Torx bits
•Socket set
•Torque wrench

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Troubleshooting Malfunctioning Cruise Control in a 2020 Toyota Highlander

Step 1: Visual Inspection

Check Cruise Control Switch: Ensure that the cruise control switch on the steering wheel is free from debris and functioning correctly.
Check Fuses: Locate the fuse box (usually under the dashboard or in the engine compartment) and inspect the cruise control fuse for continuity. Replace if blown.
Inspect Wiring: Look for any visible damage to the wiring harness connected to the cruise control system.

Step 2: Scan for Diagnostic Trouble Codes (DTCs)

Tools Required: OBD-II Scanner
Instructions:
1. Connect the OBD-II scanner to the vehicle’s diagnostic port (usually located under the dashboard).
2. Turn the ignition to the "ON" position (do not start the engine).
3. Scan for any trouble codes related to the cruise control system.
4. Document any codes retrieved and research them for specific troubleshooting steps.

Step 3: Check Brake Pedal Position Switch

The cruise control system is designed to disengage if the brake pedal is pressed.
Tools Required: Multimeter
Instructions:
1. Locate the brake pedal position switch (usually mounted near the brake pedal).
2. Disconnect the switch connector.
3. Use a multimeter to test for continuity. When the brake pedal is not pressed, there should be continuity.
4. If there is no continuity when the pedal is not pressed, replace the switch.

Step 4: Test the Throttle Position Sensor (TPS)

The cruise control relies on the TPS to maintain speed.
Tools Required: Multimeter
Instructions:
1. Locate the TPS on the throttle body.
2. Disconnect the TPS connector.
3. Use the multimeter to measure the voltage output while manually moving the throttle plate (ensure the ignition is ON). The voltage should change smoothly as the throttle opens and closes.
4. If the voltage output is erratic or does not change, replace the TPS.

Step 5: Inspect Vehicle Speed Sensor (VSS)

The VSS provides vehicle speed information to the cruise control system.
Tools Required: OBD-II Scanner, Multimeter
Instructions:
1. Using the OBD-II scanner, monitor vehicle speed data while driving. If the speed reading is erratic or zero, investigate the VSS.
2. Check the VSS wiring and connector for damage.
3. If necessary, test the VSS using a multimeter to ensure it is functioning correctly.

Repair Instructions

Based on findings from the diagnostic steps, follow the appropriate repair instructions.

Replacing the Cruise Control Switch

Tools Required: Screwdriver set, Torx bits
Instructions:
- Disconnect the battery.
- Remove the airbag module and steering wheel (refer to your service manual for specific instructions).
- Unscrew and replace the cruise control switch.
- Reassemble everything and reconnect the battery.

Replacing the Brake Pedal Position Switch

Tools Required: Screwdriver
Instructions:
- Disconnect the battery.
- Remove the old brake pedal position switch by unscrewing it from the mounting bracket.
- Install the new switch and reconnect the battery.

Replacing the Throttle Position Sensor

Tools Required: Socket set, Screwdriver
Instructions:
- Disconnect the battery.
- Remove the air intake duct to access the throttle body.
- Unbolt and unplug the old TPS from the throttle body.
- Install the new TPS, ensuring it is aligned correctly.
- Reassemble everything and reconnect the battery.

Replacing the Vehicle Speed Sensor

Tools Required: Socket set, Torque wrench
Instructions:
- Disconnect the battery.
- Locate the VSS (generally found on the transmission).
- Remove the wiring connector and unbolt the sensor.
- Install the new VSS, making sure it is torqued to manufacturer specifications.
- Reconnect the battery.

Final Steps

Test the Cruise Control: After performing repairs, take the vehicle for a test drive to ensure the cruise control operates correctly.
Clear Codes: If any DTCs were retrieved, use the OBD-II scanner to clear them and ensure no new codes reappear after testing.

Following these steps should help you troubleshoot and resolve any issues with the cruise control system in your 2020 Toyota Highlander. If issues persist, consider consulting a certified technician for further diagnosis.