The BMW M240i uses D1S and H15 bulbs for high beam headlight functions, while low beam headlight operations require D1S and H7 bulb sizes. The replacement chart covers 2017 to 2018 model production years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The BMW M240i for model years 2017-2018 accommodates two distinct headlamp system types: HID (high-intensity discharge) and halogen capsule. The specific bulb required depends entirely on which headlamp system the vehicle was equipped with at the factory.
The D1S is an HID xenon discharge bulb operating at 85V and 35W. Unlike halogen bulbs, it incorporates an integral ignitor within the bulb unit itself and is designed exclusively for projector-type housings. It follows the ECE standard, which governs lighting equipment across Europe and much of the world.
The D1S uses a PK32d-2 base. Because the ignitor is built into the bulb rather than housed separately in the vehicle, D1S bulbs are not interchangeable with other HID types such as D2S, which uses an external ignitor configuration.
On HID-equipped M240i vehicles for 2017-2018, the D1S serves both the high beam and low beam functions, meaning a single bulb type handles both lighting roles within the projector housing.
The H15 is a dual-filament halogen bulb rated at 12V with a 55W filament and a 15W filament, using a PGJ23t-1 base. The two filaments allow it to serve the high beam function while the lower-wattage filament handles a secondary role, typically a daytime running light function.
The H7 is a single-filament halogen bulb rated at 12V and 55W, using a PX26d base. It holds ECE approval and is also approved for use in the United States and Japan, giving it broader regulatory acceptance than many other ECE-standard bulb types.
On halogen-equipped M240i vehicles for 2017-2018, the high beam and low beam positions use different bulb types. The H15 occupies the high beam position while the H7 occupies the low beam position. These two bulbs have different bases and wattage configurations and are not interchangeable with each other.
All three bulb types specified for the M240i conform to ECE standards. The H15 and H7 are halogen technology, while the D1S is a gas-discharge technology operating at a significantly higher voltage, requiring compatible ballast and ignitor circuitry present only in HID-equipped vehicles.