How to Reset the E90 Cabin Air Filter Warning

1. Replace the cabin air filter if you have not done so already. Open the hood and examine the passenger side of the engine bay near the firewall to find the cabin air filter housing. The filter extends from one end of the engine bay to the other.
2. Remove the six 8mm bolts from around the cabin air filter housing. Lift the cover off to expose the filter.
3. Remove the old filter and discard it. Insert the new filter, replace the cover and tighten the bolts.
4. Insert your smart key into the electronic ignition. Press the 'Engine Start/Stop' button without placing your foot on the brake (or on the clutch, if it's a manual transmission). Wait for the service warning light to disappear.
5. Press and hold the trip odometer reset button (on instrument panel). Wait for the oil can icon to appear (it will appear after the service triangle) to indicate you are at the service menu.
6. Toggle the indicator stalk until you reach 'Cabin Filter.' Press and hold the 'BC' button at the end of the stalk to reset the interval and turn off the warning display.