how to troubleshoot Tesla Model 3 Highland (2024-present) failing battery

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the parking brake is engaged.
• Disconnect the vehicle from any charging source.

2. Inspect and Clean Battery Connections

• Tools Required: Socket set, wire brush, cleaning solution.
• Sub-steps:
  1. Remove the access panel to the battery terminals.
  2. Disconnect the negative terminal first, followed by the positive terminal.
  3. Clean the terminals and cable ends using a wire brush and cleaning solution.
  4. Reconnect the positive terminal first, then the negative terminal. Ensure they are tightened to manufacturer specifications.

3. Update Battery Management Software

• Tools Required: Tesla app or a computer with Tesla software.
• Sub-steps:
  1. Connect the vehicle to Wi-Fi.
  2. Check for any available software updates in the vehicle settings.
  3. Follow the prompts to install the updates, if necessary.

4. Replace the Battery Pack (if required)

• Tools Required: Torque wrench, battery lifting equipment, socket set.
• Sub-steps:
  1. Safely lift the vehicle using a jack and secure it with jack stands.
  2. Remove the underbody shield to access the battery pack.
  3. Disconnect all electrical connectors from the battery pack.
  4. Unscrew the mounting bolts securing the battery pack to the chassis.
  5. Carefully lower the battery pack and remove it from the vehicle.
  6. Install the new battery pack by reversing the removal steps, ensuring all connections are secure.
  7. Torque all bolts to manufacturer specifications.