why is my BMW 3 Series E90/E91’s engine light on after changing the oil?

Solution

1. Preparation

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

2. Check Oil Level

• Tools Required: Oil dipstick
• Remove the dipstick from the tube and wipe it clean with a lint-free cloth.
• Reinsert the dipstick fully, then remove it again to check the oil level.
• If the oil level is low, add the appropriate type of oil as specified in the owner's manual.

3. Inspect Oil Filter

• Tools Required: Oil filter wrench, rag
• Locate the oil filter and ensure it is tightly secured.
• Use the oil filter wrench to tighten the filter if it is loose.
• Inspect for any oil residue around the filter indicating a potential leak.

4. Check for Leaks

• Tools Required: Flashlight
• Visually inspect the oil pan and surrounding areas for any signs of oil leakage.
• If leaks are present, determine the source and address accordingly (may require resealing or replacing components).

5. Clear Error Codes

• Tools Required: OBD-II scanner
• Reconnect the negative battery terminal.
• Use the OBD-II scanner to erase any error codes from the vehicle’s computer.
• Start the engine and observe if the check engine light reappears.