why does my BMW 5 Series F10/F11 (2010-2017) have a constant check engine light

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, fuel pressure gauge, torque wrench.
• Gather necessary parts based on diagnostic codes (e.g., spark plugs, ignition coils).
• Ensure the vehicle is parked on a flat surface and the engine is cool.

2. Address Error Codes

• Sub-steps:
  1. Connect the OBD-II scanner and retrieve the trouble codes.
  2. Note down the codes and refer to a repair manual for detailed explanations and diagnostics.

3. Repair Identified Issues

• Sub-steps:
  1. If codes indicate faulty spark plugs or ignition coils:
     • Remove the engine cover (if applicable).
     • Disconnect the battery.
     • Remove ignition coil bolts and pull out the coils.
     • Replace faulty coils and/or spark plugs with new ones, ensuring proper torque specifications (typically 15 Nm for plugs).
  2. If air intake issues are present:
     • Remove the air filter housing.
     • Inspect and clean the mass airflow sensor (if applicable).
     • Replace the air filter if clogged.
  3. If fuel pressure is low:
     • Connect a fuel pressure gauge to the fuel rail.
     • If pressure is below specifications, inspect the fuel pump and replace if necessary.

4. Clear Codes and Test

• Sub-steps:
  1. After repairs, reconnect battery terminals.
  2. Use the OBD-II scanner to clear the codes.
  3. Start the engine and check for any reoccurrence of the check engine light.