what causes my BMW 3 Series F30/F31 (2012-2019) engine light to stay on

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery negative terminal to ensure safety while working on electrical components.

2. Address Error Codes

• Connect the OBD-II scanner and retrieve error codes.
• Research codes and identify the affected component or system.
• Clear the codes after repairs to reset the engine light.

3. Inspect and Replace Components

a. Gas Cap Inspection

• Remove the gas cap and visually inspect for cracks or damage.
• Replace with a new gas cap if necessary.

b. Ignition System

• Remove spark plugs using a socket set; inspect for wear and carbon buildup.
• Replace spark plugs with OEM equivalents if needed.
• Check ignition coils for functionality; replace any faulty coils.

c. Air Intake System

• Inspect air filter for dirt and clogs; replace if necessary.
• Check for vacuum leaks in hoses and connections; repair or replace as needed.

4. Fuel System Check

• Use a fuel pressure gauge to measure fuel pressure; compare to manufacturer specifications.
• If pressure is low, inspect fuel pump and fuel filter for issues; replace as necessary.

5. Reassemble and Test

• Reconnect all components and ensure proper tightness.
• Reconnect the battery negative terminal.
• Start the engine and monitor for any new or persistent warning lights.