how to fix the P0301 code on my BMW 3 Series G20/G21 (2019-2024)

Solution

1. Preparation

• Gather tools and parts required.
• Disconnect the battery to ensure safety during repairs.
• Allow the engine to cool down before starting work.

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil by unscrewing the bolts and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket and inspect it for damage or excessive wear.
• Install a new spark plug, ensuring the correct gap setting (0.028-0.032 inches).
• Torque the spark plug to the manufacturer's specification (typically around 18 lb-ft).

3. Inspect and Replace Ignition Coil

• Remove the ignition coil if not already removed.
• Visually inspect for cracks or corrosion.
• Replace the ignition coil if necessary with a new OEM part.
• Reattach the ignition coil and ensure the electrical connector is securely connected.

4. Check Fuel Injector

• Disconnect the fuel injector connector for cylinder 1.
• Use a multimeter to test the resistance of the fuel injector; it should meet manufacturer specifications (usually around 12-16 ohms).
• If faulty, replace with a new injector.
• Reconnect the injector connector.

5. Compression Test

• Remove the spark plug for cylinder 1.
• Insert a compression gauge into the spark plug hole.
• Crank the engine and record the compression reading; it should be within the manufacturer’s specified range (typically around 140-200 psi).
• If the compression is low, further investigation into potential mechanical issues is necessary.