why does my Toyota Highlander Third Generation (2014-2019) have a high-pitched noise when starting

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a level surface, and the engine is off.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Serpentine Belt

• 1.1 Visually inspect the serpentine belt for cracks or fraying.
• 1.2 Use a wrench to relieve tension on the belt tensioner and remove the belt.
• 1.3 Install the new serpentine belt by routing it according to the belt routing diagram under the hood.
• 1.4 Reapply tension to the tensioner and ensure the belt is seated properly.

3. Check and Replace Starter Motor (if necessary)

• 2.1 Remove the starter motor by disconnecting the electrical connections and removing the mounting bolts.
• 2.2 Inspect the starter for any signs of excessive wear or damage.
• 2.3 Install the new starter motor, ensuring all connections are secure and bolts are torqued to specifications (typically 10-15 ft-lbs).

4. Inspect and Replace Alternator (if necessary)

• 3.1 Disconnect the battery and remove the alternator belt.
• 3.2 Unplug the electrical connectors and remove the mounting bolts.
• 3.3 Install the new alternator, reconnect electrical connections, and reinstall the belt.