my Volkswagen Passat B8 (2015-2022) has a hard time starting in cold weather, what's wrong?

Solution

1. Preparation

• Gather tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to avoid any electrical shorts.

2. Battery Inspection and Replacement (if necessary)

• Sub-steps:
  1. Remove the battery terminals, starting with the negative terminal.
  2. Use a multimeter to test the battery voltage.
  3. If the voltage is below 12.4 volts, replace the battery with a new one that meets OEM specifications.
  4. Reconnect the battery terminals, ensuring a tight fit.

3. Starter Motor Testing and Replacement (if necessary)

• Sub-steps:
  1. Remove the starter motor from the vehicle following the manufacturer’s guidelines.
  2. Test the starter motor using a bench tester to check for proper function.
  3. If faulty, replace the starter motor with an OEM equivalent.
  4. Reinstall the starter motor and secure it with the specified torque settings (typically around 20-25 Nm).

4. Fuel System Inspection

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Connect the fuel pressure gauge and turn the ignition to the "ON" position without starting the engine.
  3. Check that the fuel pressure is within the manufacturer’s specifications (usually around 50-60 psi).
  4. If pressure is low, inspect the fuel pump and fuel filter for issues and replace if necessary.