how to troubleshoot my Volkswagen Tiguan First Generation (2007-2018) that won’t start

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, socket set, and screwdrivers.
• Ensure the vehicle is in a safe location and on level ground.
• Disconnect the negative terminal of the battery to prevent electrical shorts.

2. Battery Inspection

• Sub-step 1: Inspect battery terminals for corrosion. Clean them using a battery terminal cleaner or a mixture of baking soda and water.
• Sub-step 2: Tighten any loose connections and ensure the battery is firmly mounted.
• Sub-step 3: Reconnect the negative terminal and check voltage again.

3. Fuel System Inspection

• Sub-step 1: Turn the ignition key to the "on" position without starting the engine and listen for the fuel pump sound (a humming noise).
• Sub-step 2: If no sound is heard, locate the fuel pump relay and test it for operation. Replace if faulty.
• Sub-step 3: If the relay is functional, test the fuel pump directly by disconnecting the fuel line and applying power to the pump (ensure safety precautions are followed).

4. Ignition System Inspection

• Sub-step 1: Inspect ignition coils and spark plugs for wear or damage.
• Sub-step 2: If necessary, replace faulty coils or plugs.
• Sub-step 3: Check the ignition switch operation; replace if it shows signs of failure.

5. Final Checks

• Sub-step 1: Clear any existing trouble codes from the OBD-II scanner.
• Sub-step 2: Attempt to start the engine; if it fails, further examine the starter motor and wiring.