my Volkswagen Golf MK7 (2015-2019) has an illuminated check engine light and a P0301 code, what does...

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery.
• Ensure the vehicle is on a flat, stable surface.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if present.
  2. Locate the spark plug for cylinder 1 (refer to the owner’s manual for location).
  3. Disconnect the ignition coil connector.
  4. Remove the ignition coil using a socket set.
  5. Unscrew the spark plug with a spark plug socket.
  6. Inspect the spark plug for wear (color, gap).
  7. If damaged, replace with a new spark plug (specifications: NGK or Bosch equivalent).
  8. Reinstall the spark plug and ignition coil, reconnecting the connector.

3. Inspect and Replace Ignition Coil

• Sub-steps:
  1. If the spark plug is fine, proceed to inspect the ignition coil.
  2. Remove the ignition coil from cylinder 1 as described above.
  3. Test the ignition coil with a multimeter (check primary and secondary resistance).
  4. If faulty, replace the coil with a new unit.
  5. Reinstall the ignition coil and reconnect the connector.

4. Check Fuel Injector

• Sub-steps:
  1. If misfire persists, inspect the fuel injector for cylinder 1.
  2. Disconnect the fuel injector connector.
  3. Remove the fuel rail (if necessary) to access the injector.
  4. Test the injector with a multimeter for proper resistance.
  5. Clean or replace the injector if it is clogged or damaged.
  6. Reinstall the fuel rail and reconnect the injector.

5. Compression Test

• Sub-steps:
  1. Remove spark plugs from all cylinders.
  2. Insert a compression tester into cylinder 1.
  3. Crank the engine and record the compression reading.
  4. Compare the reading to the manufacturer's specifications.
  5. If compression is low, further diagnostics are necessary for potential internal engine issues.

Tools Required:

• OBD-II scanner
• Socket set
• Spark plug socket
• Torque wrench
• Multimeter
• Compression tester
• Fuel pressure gauge (if checking fuel delivery)

Parts Required:

• Spark plug (for cylinder 1)
• Ignition coil (if needed)
• Fuel injector (if needed)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect the battery before working on electrical components.
• Allow the engine to cool before removing any components to prevent burns.