Freightliner M2 Back Up Light Bulb Size

The Freightliner M2 back up light uses a 1156 bulb size for replacement applications. The chart covers vehicle production spanning from 2002 to 2024.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	US Type	EU Type	Shop
2002-2024	1156	P21W	Check Price

Description	Type	Shop
ANSI standard (US & Canada). Single-filament bulb with BA15s bayonet base. 12V, 21W.	1156	Check Price
ECE standard (Europe & worldwide). Single-filament signalling bulb with BA15s bayonet base. 12V, 21W.	P21W	Check Price

The Freightliner M2 uses the 1156 bulb for its back up light across all model years from 2002-2024.
The 1156 is an ANSI-standardized bulb type, meaning its physical and electrical specifications are governed by a recognized industry standard used across the United States and Canada.
The 1156 operates on a 12-volt electrical system and draws 21 watts, which is consistent with standard incandescent automotive lighting output.
The bulb uses a BA15s bayonet base, which is a single-contact base that locks into its socket with a twist-and-press motion rather than a threaded connection.
The single-filament design of the 1156 means it serves one lighting function only, which in this application is the back up light circuit.
The BA15s base designation distinguishes the 1156 from visually similar bulbs such as the 1157, which uses a BA15d dual-contact bayonet base and is not interchangeable despite sharing a similar physical profile.