my Toyota Highlander Fourth Generation (2020-present) won't start and just clicks what's the problem

Solution

1. Preparation

• Tools Required: Multimeter, socket set, wrench set, OBD-II scanner, jumper wire.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Battery Inspection

• Remove the battery terminals, starting with the negative terminal.
• Clean any corrosion from the battery terminals and cable ends using a wire brush.
• Reconnect the terminals securely, ensuring a tight fit.

3. Battery Testing

• Reconnect the negative battery terminal.
• Use the multimeter to check the battery voltage; if it's below 12.4 volts, consider jump-starting the vehicle or replacing the battery if it does not hold a charge.
• If jump-starting, allow the vehicle to run for at least 15 minutes to charge the battery.

4. Starter and Wiring Inspection

• Locate the starter motor (usually positioned near the transmission).
• Check the wiring harness connected to the starter for any signs of damage or loose connections.
• If connections are secure, perform a starter motor test by applying 12 volts directly to the starter terminal using a jumper wire.
• If the starter engages and the engine cranks, the starter is functioning correctly, and further investigation into the ignition switch or relay may be needed.

5. Replacing Components (if necessary)

• If the battery or starter motor is faulty, replace the respective component:
  • For battery replacement: Ensure to match the specifications (size, CCA).
  • For starter replacement: Remove the mounting bolts and disconnect the electrical connectors before installing the new starter.