Buick LaCrosse 2017 Bulb Size
Bulb size chart
This page helps you verify the bulb sizes for the 2017 Buick LaCrosse by lighting position, so you can match the correct bulb before you buy. Because different lights on the car use different bulb types, checking the exact location is the safest way to avoid a wrong fit.
For the 2017 Buick LaCrosse, several exterior and interior positions use LED lighting, while some serviceable bulbs use specific part numbers such as D3S for the headlight high beam and low beam, 921 for the back up reverse light, and 7440 for the rear turn signal. Use the chart below to compare each bulb location with the correct size or type.
Fitment can vary by trim, lighting package, market, and body style, so always confirm the installed bulb before ordering replacements. Some versions of the 2017 LaCrosse use factory LED assemblies, while others may have halogen-style service bulbs or different connector and housing setups. If you are considering an aftermarket LED conversion, make sure the bulb base, polarity, and housing depth are compatible, and check whether the new bulb will trigger warning messages or require an adapter or resistor. The most reliable approach is to inspect the bulb currently in the vehicle and compare it with the chart before purchase.
FAQ
What headlight bulb does the 2017 Buick LaCrosse use?
The chart lists D3S for both the high beam and low beam headlight bulb on the 2017 Buick LaCrosse.
What size is the back up reverse light bulb on this model?
The back up reverse light bulb is listed as 921.
What bulb does the rear turn signal use?
The rear turn signal light bulb is listed as 7440.
What is the brake light bulb size for the 2017 Buick LaCrosse?
The brake light bulb is listed as 7440R.
Are the front turn signal and parking lights LED?
Yes. The front turn signal light bulb and parking light bulb are listed as LED on this page.
Does the 2017 Buick LaCrosse use LED daytime running lights?
Yes. The daytime running light bulb is listed as LED.
What bulb is used for the license plate lights?
The license plate light bulb is listed as 2825 or 98.
What bulb fits the trunk or cargo area light?
The trunk or cargo area light uses 194 or 7441.
What bulb is used for the interior door light and stepwell light?
Both the interior door light bulb and the stepwell light bulb are listed as 194 or 7441.
What bulb does the vanity mirror light use?
The vanity mirror light bulb is listed as 7065.
What fog light bulb does the 2017 Buick LaCrosse use?
The front fog light bulb is listed as H11 LED or H16 LED, depending on the vehicle setup.
Do all 2017 Buick LaCrosse models use the same bulbs?
Not always. Trim level, lighting package, market, and body style can change the bulb type or whether a light is LED or serviceable.
Should I check the old bulb before ordering a replacement?
Yes. Checking the installed bulb is the best way to confirm fitment, especially on a vehicle with mixed LED and non-LED lighting positions.
Can I replace a factory bulb with an LED upgrade?
Often yes, but the replacement must match the socket and fit the housing. Some LED conversions may need resistors, adapters, or extra clearance.