how to fix P0301 code in Volkswagen Tiguan First Generation (2007-2018)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, noid light, vacuum gauge.
• Ensure the vehicle is on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Replace Spark Plug and Ignition Coil

1. Remove the engine cover (if applicable) by unscrewing any bolts or clips.
2. Disconnect the electrical connector from the ignition coil of cylinder 1.
3. Remove the ignition coil by unscrewing the retaining bolts and pulling it out.
4. Remove the spark plug using a spark plug socket and ratchet, inspect for signs of wear or damage.
5. Install the new spark plug by hand, then torque it to the manufacturer's specifications (usually around 13 lb-ft).
6. Reinstall the ignition coil, secure it with bolts, and reconnect the electrical connector.

3. Test Fuel Injector

1. Disconnect the fuel injector connector for cylinder 1.
2. Use a noid light to check if the injector is receiving a signal. If the light does not flash, check the wiring and ECM.
3. If the injector is not functioning, replace it with a new one.
4. Reconnect the fuel injector connector after testing or replacement.

4. Perform Compression Test

1. Remove the spark plug from cylinder 1.
2. Insert the compression tester into the spark plug hole.
3. Crank the engine for about 5-10 seconds and record the compression reading.
4. Compare the reading to manufacturer specifications. If low, further investigation is needed (head gasket, valve issues).