Land Rover Discovery Back Up Light Bulb Size

The Land Rover Discovery back up light utilizes a P21W bulb size for illumination purposes. Available data covers the specific time range from 1994 through 2004 for the vehicle.

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	Bulb Size
1994-2004	P21W

Bulb Specifications

Description	Bulb Size
ECE standard (Europe & worldwide). Single-filament signalling bulb with BA15s bayonet base. 12V, 21W.	P21W

Other Locations

Additional Notes

The Land Rover Discovery uses the P21W bulb as the back up light bulb across the 1994-2004 model years.
The P21W is an ECE-standard bulb, meaning it conforms to the Economic Commission for Europe's regulations, which govern automotive lighting across European and many worldwide markets.
This bulb operates on a 12-volt electrical system and draws 21 watts, which is typical for single-filament incandescent signalling applications.
The P21W uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin offset, distinguishing it from double-contact variants such as the BA15d.
Because the P21W is a single-filament bulb, it serves one dedicated function per housing, in this case the reverse light, rather than combining multiple functions within one bulb.
The BA15s base type is not universally interchangeable with other bayonet bases. Substituting a BA15d or BAY15d bulb in a BA15s socket would result in an improper fit due to differing pin configurations.