Jaguar XJ6 Back Up Light Bulb Size

The Jaguar XJ6 back up light utilizes a P21W bulb size for the rear illumination system. Data for the specified component covers the range from 1981 through 1997.

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
1981-1997	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 Jaguar XJ6 uses the P21W bulb for the back up light position across all listed model years, spanning 1981-1997.
The P21W is an ECE-standard bulb, meaning it conforms to the Economic Commission for Europe's regulations, which are widely adopted across European and international vehicle markets.
This bulb operates on a 12-volt electrical system and draws 21 watts, which is typical for single-filament signalling applications such as reverse lights.
The P21W uses a BA15s bayonet base, a single-contact fitting where the "s" denotes a single pin offset, distinguishing it from the dual-contact BA15d variant.
Because the P21W is a single-filament bulb, it serves dedicated on/off functions rather than dual-intensity roles such as combined brake and tail light duties.
The BA15s base type is not interchangeable with BA15d sockets due to the difference in contact configuration, and substituting one for the other is not compatible.
The uninterrupted use of the P21W across the entire 1981-1997 span of the XJ6 indicates a consistent electrical and socket specification throughout the model's production run as listed.