Nissan Frontier Back Up Light Bulb Size

Additional Notes

• The Nissan Frontier uses three distinct back up light bulb types across its model years: the 921, the 2456, and the 3156, all of which conform to ANSI standards recognized in the United States and Canada.
• The 921 bulb is a T15 wedge-base type rated at 12 volts and 16 watts, and it is the back up light specification for the Nissan Frontier across the 2005-2020 model years.
• The 3156 is a single-filament T25 wedge-base bulb rated at 12 volts and 27 watts, producing notably higher wattage output than the 921.
• The 2456 is a festoon-style bulb rated at 12 volts and is designated for specialty applications, differing in physical form from the wedge-base 921 and 3156 types.
• Wedge-base bulbs such as the 921 and 3156 are not interchangeable with festoon-style bulbs such as the 2456, as the two types use fundamentally different mounting and contact configurations.
• The 921 and 3156 are both wedge-base designs, but their different base sizes (T15 versus T25) and wattage ratings mean they are not interchangeable with each other.
• The 2003-2004 Frontier models share the 2456 festoon bulb specification, while the 1998, 2000, and 2002 models use the higher-wattage 3156 wedge bulb instead.
• The 1999 and 2001 Frontier models use the 2456 festoon bulb, placing them in the same specification group as the 2003-2004 models despite the non-consecutive years.