how to fix B2579 code in Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather tools and materials.
• Disconnect the vehicle’s battery to ensure safety while working on electrical components.

Tools Required:

• OBD-II scanner
• Multimeter
• Screwdriver set
• Torque wrench
• Replacement key fob battery (if needed)

2. Inspect Key Fob

• Remove the key fob casing using a small screwdriver.
• Replace the battery with a new, compatible battery (typically CR2032).
• Reassemble the key fob and test its functionality.

3. Check Smart Key ECU

• Locate the Smart Key ECU in the vehicle (usually under the dashboard or near the steering column).
• Remove any covering panels to access the ECU.
• Disconnect the ECU connector and inspect for corrosion or damage.
• Reconnect the ECU and ensure it is securely mounted.

4. Inspect Wiring and Antenna

• Locate the keyless entry antenna, usually near the ignition switch or under the dashboard.
• Check the wiring harness for any frays, breaks, or loose connections.
• Tighten any loose connections and repair any damaged wiring using electrical tape or by replacing sections as necessary.

5. Reconnect Battery and Test

• Reconnect the vehicle's battery.
• Start the vehicle using the push-button ignition and check if the keyless entry system functions properly.
• Test all key fob functions, including lock/unlock and remote start if equipped.