why does my Toyota Highlander Fourth Generation (2020-present) make a whining noise when starting

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the negative battery terminal to avoid electrical shock.

2. Battery Inspection

• Tools Required: Multimeter
• Check the battery voltage: It should read between 12.4V and 12.7V for a healthy battery.
• If the voltage is low, charge or replace the battery as needed.

3. Serpentine Belt Inspection

• Tools Required: Socket set, flashlight
• Visually inspect the serpentine belt for damage; replace if cracked or worn.
• Check tension by applying pressure to the belt; it should not deflect more than half an inch.

4. Starter Motor Inspection

• Tools Required: Socket set, torque wrench
• Remove the starter motor by disconnecting the electrical connectors and bolts.
• Inspect the starter for signs of wear or damage, including the gear mechanism.
• Replace the starter if necessary, ensuring all connections are secure and torqued to manufacturer specifications.

5. Reassemble and Test

• Reinstall the starter and serpentine belt as necessary.
• Reconnect the negative battery terminal.
• Start the engine and listen for any whining noises.