my BMW 5 Series G30/G31 (2017-2024) has a check engine light and misses, what to do?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent electrical shorts.

2. Scan for Codes

• Use an OBD-II scanner to retrieve error codes.
• Note any codes related to misfire (e.g., P0300-P0306) and diagnose accordingly.

3. Replace Ignition Components

• Spark Plugs:

  • Remove the engine cover if necessary.
  • Use a spark plug socket and ratchet to remove the spark plugs.
  • Inspect the old plugs for wear.
  • Install new spark plugs to the manufacturer's torque specifications (typically around 18 lb-ft).

• Ignition Coils:

  • Disconnect the wiring harness from each ignition coil.
  • Remove the screws or bolts securing the coils using a socket set.
  • Replace with new ignition coils, ensuring they are seated properly.

4. Check and Replace Fuel Filter (if applicable)

• Locate the fuel filter and relieve fuel pressure by removing the fuel pump fuse and running the engine until it stalls.
• Disconnect the fuel lines from the filter using appropriate fuel line tools.
• Replace the filter with a new one and reconnect the fuel lines securely.

5. Clean or Replace MAF Sensor

• Locate the MAF sensor in the intake system.
• Disconnect the electrical connector and remove the sensor.
• Clean the MAF sensor with a specific MAF cleaner or replace it if damaged.

6. Reconnect Battery and Clear Codes

• Reconnect the battery terminals.
• Use the OBD-II scanner to clear any existing trouble codes.
• Start the vehicle and monitor for any reoccurrence of the check engine light.