Acura TSX Headlight Bulb Size

The Acura TSX high beam headlight uses a 9005 bulb size while the low beam headlight requires a D2S bulb size. The replacement chart covers 2004 through 2010 model years with corresponding bulb size specifications.

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

High Beam Headlight

If US Type and EU Type show the same value, a direct cross-reference for this bulb is not available or the data is insufficient.

Years	US Type	EU Type	Shop
2009-2010	9005	HB3	Check Price
2004-2008	H1	H1	Check Price

Low Beam Headlight

Years	Bulb Type	Shop
2004-2010	D2S	Check Price

Bulb Specifications

Description	Type	Shop
ANSI standard (US & Canada). Single-filament halogen bulb with P20d base. 12V, 65W.	9005	Check Price
ECE standard (Europe & worldwide). Single-filament halogen bulb with P14.5s base. Also approved in the US and Japan. 12V, 55W.	H1	Check Price
ECE standard (Europe & worldwide). HID (xenon) discharge bulb with P32d-2 base, for projector-type housings. Requires external ignitor. 85V, 35W.	D2S	Check Price

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Additional Notes

The Acura TSX uses the D2S bulb type across all low beam headlight positions for every model year in the specifications, from 2004-2010. The D2S is a high-intensity discharge (HID) xenon bulb rated at 85V and 35W, built to the ECE standard used in Europe and worldwide. It features a P32d-2 base and is designed exclusively for projector-type housings.
Unlike conventional halogen bulbs, the D2S does not contain a self-contained ignition source. It requires a separate external ignitor to generate the high-voltage arc needed to produce light, meaning the surrounding housing assembly is a functional part of the lighting system rather than a passive enclosure.
The high beam headlight position on the Acura TSX (2004-2008) uses the H1 bulb, an ECE-standard single-filament halogen rated at 12V and 55W. Its P14.5s base is a pin-type connector, and while the H1 originates from European standards, it carries approval for use in the United States and Japan as well.
For the 2009-2010 model years, the high beam headlight position shifts from the H1 to the 9005 bulb. The 9005 is an ANSI-standard halogen bulb rated at 12V and 65W, with a P20d base. It operates at a higher wattage than the H1, which corresponds to a higher light output from the high beam circuit in those years.
The H1 and 9005 bulbs are not interchangeable. They differ in base type, wattage, and regulatory standard, meaning a socket designed for one will not physically or electrically accept the other. This distinction is relevant to the TSX high beam position, where the two bulb types apply to different production years.
The D2S bulb, used in the low beam position, operates at 85V, which is substantially higher than the 12V supply voltage of the vehicle's electrical system. A ballast unit steps up the voltage to sustain the xenon arc after the ignitor fires the initial discharge, making both components necessary for the low beam circuit to function.
The D2S designation includes the suffix "S," which indicates compatibility with projector-type optical housings rather than reflector housings. A related bulb, the D2R, carries an internal shield for use in reflector housings and is not a substitute for the D2S in projector applications such as those found in the TSX low beam position.