How do I fix a malfunctioning cruise control system in a 2021 Toyota Highlander?

Fixing a Malfunctioning Cruise Control System in a 2021 Toyota Highlander

Tools Required

• OBD-II Scanner
• Multimeter
• Screwdrivers (Phillips and flathead)
• Pliers
• Torque wrench
• Replacement fuses, if necessary

Repair Instructions

Step 1: Visual and Electrical Inspection

1. Inspect the Cruise Control Switch: Remove the steering wheel cover if necessary and check the cruise control switch for damage or wear.
2. Check Wiring: Look for frayed wires or disconnected connectors related to the cruise control system.

Step 2: Scan for Codes

1. Connect OBD-II Scanner: Plug the scanner into the OBD-II port under the dashboard.
2. Retrieve Codes: Follow the scanner instructions to read any stored codes. Note any that pertain to cruise control.

Step 3: Check Fuses

1. Locate the Fuse Box: Refer to the owner’s manual for the fuse box location.
2. Inspect the Cruise Control Fuse: Remove and inspect the fuse related to cruise control. Replace if blown.

Step 4: Test Brake Pedal Switch

1. Locate the Brake Pedal Switch: Find the switch mounted above the brake pedal.
2. Test the Switch: Use a multimeter to check for continuity. If the switch does not function, replace it.

Step 5: Inspect the Speed Sensor

1. Locate the Speed Sensor: Typically found on or near the transmission.
2. Test the Sensor: Check for proper voltage output while the vehicle is moving. If faulty, replace the speed sensor.

Step 6: Inspect Throttle Control

1. Check Throttle Position Sensor (TPS): Use a multimeter to measure the voltage output of the TPS. It should vary smoothly with throttle position.
2. Inspect Throttle Body: Ensure there are no obstructions and that it opens and closes smoothly. Clean if necessary.

Step 7: Reassemble and Test

1. Reassemble any removed components: Ensure all wiring and connectors are reattached securely.
2. Clear DTCs: If codes were present, clear them from the OBD-II scanner.
3. Test the Cruise Control: Take the vehicle for a test drive to confirm that the cruise control system is functioning properly.

Conclusion

If after following these steps the cruise control system still does not function correctly, it may be necessary to seek assistance from a professional technician or dealership service department for further diagnosis and repair.