what causes the P0302 code on my BMW 5 Series G30/G31 (2017-2024)

Solution

1. Preparation

• Gather tools: OBD-II scanner, multimeter, compression tester, socket set, torque wrench.
• Ensure safety by disconnecting the battery.

2. Inspect Spark Plug

• Remove the spark plug from cylinder 2 using a socket set.
• Inspect for signs of wear, fouling, or damage.
• Replace with a new spark plug if necessary.
• Torque the new spark plug to the manufacturer’s specifications (typically around 18-25 Nm).

3. Check Ignition Coil

• Disconnect the ignition coil connector for cylinder 2.
• Use a multimeter to measure the resistance of the ignition coil (should typically be around 0.5-1.0 ohms).
• If the resistance is out of spec, replace the ignition coil with a new one.
• Reinstall and reconnect the ignition coil.

4. Test Fuel Injector

• Disconnect the fuel injector connector for cylinder 2.
• Use a noid light to check for injector pulse while cranking the engine.
• If no pulse is detected, check wiring and replace the injector if necessary.
• Reconnect the fuel injector connector.

5. Conduct Compression Test

• Remove the spark plug from cylinder 2.
• Insert the compression tester and crank the engine.
• Record the compression reading (should be above 150 psi).
• If the reading is low, further investigation into valve or piston damage may be required.