Pontiac Trans Sport Dome Light Bulb Size

The Pontiac Trans Sport dome light utilizes bulb sizes 212-2, 561, and 906 depending on the specific production period. Available information covers a span from 1990 through 1998.

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
1997-1998	212-2
1995-1996	561
1993	561
1991-1992	906
1990	561

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Festoon bulb, 41mm length, SV8.5 base. 12V, 12W.	212-2
ANSI standard (US & Canada). Festoon bulb, 44mm length, end-cap contacts. 12V, 12W.	561
ANSI standard (US & Canada). Miniature wedge bulb (T10). 12V, 8W.	906

Other Locations

Additional Notes

The Pontiac Trans Sport dome light draws from three distinct bulb types across its production run: the 212-2, the 561, and the 906, all of which conform to ANSI standards recognized in both the United States and Canada.
The 561 is the most frequently specified bulb across the Trans Sport's model years, covering 1990, 1993, and 1995-1996.
Both the 212-2 and the 561 are festoon-style bulbs, meaning they mount horizontally between two contact points rather than inserting into a socket. Despite this shared form factor, the two are not interchangeable due to a difference in length and base type.
The 212-2, used in the 1997-1998 Trans Sport, measures 41mm in length and uses an SV8.5 base, which features a metal cap that grips into a dedicated socket rather than relying solely on end-cap pressure.
The 561, used across multiple earlier model years, measures 44mm in length and uses end-cap contacts. The 3mm difference in length relative to the 212-2 means the two bulbs will not seat correctly in each other's housings.
Both the 212-2 and the 561 operate at 12V and 12W, so their electrical draw is identical even though they are physically incompatible with each other.
The 906, specified for the 1991-1992 Trans Sport, is a T10 miniature wedge bulb, a fundamentally different construction from the festoon types used in other years. It inserts into a wedge-style socket and cannot be substituted with either festoon bulb.
At 8W, the 906 draws less power than the 12W festoon bulbs used in other Trans Sport model years, reflecting a difference in both bulb technology and socket design between those production periods.
The 1994 model year is not represented in the specifications, so no dome light bulb size is attributed to it within this data set.
Because the 1991-1992 Trans Sport uses a wedge-base socket and the 1993 model uses a festoon-base socket, the dome light housing design changed between the 1992 and 1993 model years, making bulbs from those adjacent years incompatible with each other.