2015 Subaru Outback Bulb Sizes & Replacement Guide

Quick reference

The 2015 Subaru Outback, part of the fifth generation (2015-2019), offers a practical and capable vehicle for various adventures. When it comes to lighting, understanding the specific bulb sizes and types is crucial for maintenance and upgrades. This guide provides a comprehensive breakdown for your 2015 Outback.

For the low beam headlights, most 2015 Outback models came equipped with H11 halogen bulbs. However, some higher trim levels, particularly those with the optional EyeSight Driver Assist System, featured HID (High-Intensity Discharge) projector headlights, which utilize D4S bulbs. It's important to check your specific vehicle's headlights to determine if you have the standard halogen or the HID setup.

The high beam headlights consistently use H9 halogen bulbs across all trims. Fog lights, where equipped, typically use H16 (Type 2) halogen bulbs. The Daytime Running Lights (DRLs) on the 2015 Outback primarily use 9005 halogen bulbs, often operating at a reduced voltage compared to when they function as high beams.

For turn signals, both the front and rear utilize 7440NA amber halogen bulbs. The "NA" signifies Natural Amber, ensuring the correct color output. Brake and tail lights share a dual-filament 7443 halogen bulb, providing both the dimmer tail light function and the brighter brake light output. Reverse lights are commonly 921 halogen bulbs, offering bright white light for visibility when backing up.

Smaller exterior lights include 168 halogen bulbs for the license plate lights and rear side markers, while the front side markers typically use 194 halogen bulbs. Inside the cabin, the dome light usually takes a DE3175 festoon-style halogen bulb, and the map lights commonly use 168 halogen bulbs.

While the factory standard largely consists of halogen bulbs, it's worth noting that some premium features or later model year refreshes within this generation might have introduced LED accents. For the 2015 model specifically, assume halogen unless you have confirmed HID low beams.

LED vs Halogen Upgrade Considerations

Upgrading your 2015 Subaru Outback's halogen bulbs to LED can offer significant benefits, including brighter light output, a more modern appearance, and longer lifespan. However, there are several key considerations to keep in mind:

CANBUS Errors: Modern vehicles like the 2015 Outback have a CANBUS (Controller Area Network Bus) system that monitors the electrical resistance of the bulbs. LED bulbs draw significantly less power than halogens. If you install LEDs without proper resistors, the CANBUS system may detect the lower power draw as a "bulb out" error, leading to dashboard warning lights (e.g., "Check Headlight" or "Brake Light Out") or hyperflashing turn signals. Many aftermarket LED bulbs come with built-in CANBUS decoders, or you may need to purchase separate load resistors.

Adapters Needed: For some applications, particularly headlights, you might need specific adapters (sometimes called retainers or holders) to properly seat the LED bulb in the headlight housing. The base of an LED bulb can sometimes differ slightly from a halogen bulb, preventing a secure fit. Always check the product description of any LED upgrade kit for your specific vehicle.

Beam Pattern: With headlight and fog light upgrades, it's crucial to ensure the LED bulbs create a proper beam pattern. Poorly designed LED bulbs can scatter light, creating glare for oncoming drivers and reducing your effective visibility, even if they appear brighter up close. Look for LED bulbs designed to mimic the filament placement of their halogen counterparts for optimal beam focus.

Heat Dissipation: LEDs generate heat, and effective heat dissipation is vital for their longevity. Many high-performance LED bulbs incorporate cooling fans or large heat sinks. Ensure there is adequate space within the light housing for proper cooling.

How to Replace Each Bulb

Replacing bulbs on your 2015 Outback generally involves straightforward procedures. Always turn off the ignition and headlights before attempting any bulb replacement.

• Headlights (Low Beam, High Beam, DRL): Access is usually from behind the headlight assembly in the engine bay. twists to remove. For HID bulbs, caution is advised due to high voltage; professional installation is recommended.
• Fog Lights: Often accessed by turning the steering wheel full lock and removing a few clips from the fender liner, or from underneath the vehicle.
• Front Turn Signals/Side Markers: Typically accessed through the engine bay, behind the headlight assembly, or sometimes by removing a few clips from the fender liner.
• Rear Turn Signals/Brake/Tail/Reverse Lights: These are usually accessed by opening the tailgate and removing screws or clips that hold the taillight assembly in place. The entire assembly often needs to be removed to access the bulbs.
• License Plate Lights: Accessed from outside, usually by removing two screws holding clear lens or prying with a trim tool.
• Dome/Map Lights: Carefully pry off the lens cover using a plastic trim tool or small flathead screwdriver. The bulbs are usually pushed or twisted into place.

For detailed, step-by-step instructions with diagrams, consult your 2015 Subaru Outback owner's manual or a reputable service manual.

Common Lighting Issues for this Generation

While the 2015 Subaru Outback is generally reliable, a few lighting-related issues can occasionally pop up for this generation:

• Premature Halogen Bulb Burnout: Some owners report that halogen bulbs, particularly headlights, tend to burn out sooner than expected. This can sometimes be attributed to voltage fluctuations, vibration, or simply the lifespan of the OEM bulbs. Opting for higher-quality aftermarket halogens or switching to LEDs can mitigate this.
• Corroded Sockets: In some cases, bulb sockets can corrode over time, leading to intermittent light function or complete failure. This is more common in areas with high humidity or road salt. Cleaning the contacts with electrical cleaner or replacing the socket can resolve this.
• DRL Resistor Issues: The DRL system often uses a resistor to dim the high beam bulbs for DRL function. If this resistor fails, the DRLs may not work, or the high beams might function abnormally. Diagnosing this typically requires a multimeter.
• HID Ballast/Igniter Failure (for equipped models): If your Outback has the factory HID low beams and one side suddenly goes out or flickers, it could indicate a failing ballast or igniter. These are more complex components than simple bulbs and usually require professional diagnosis and replacement.

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