2023 Subaru Forester — Bulb Sizes (Headlight, Tail, Fog)

Quick reference

Notes

• The 2023 Forester lineup in the U.S. is predominantly equipped with factory LED headlamps (projector low/high) and LED tail/running/brake lamps. If your vehicle has these LED assemblies, there is no replaceable bulb inside; the whole lamp must be serviced if an LED fails.
• Some base or accessory configurations may use halogen fog lamps; most Premium/Sport/Wilderness/Limited/Touring trims use LED fogs.
• Always confirm by trim/build and visually inspect your sockets before ordering. Subaru occasionally revises lamp internals mid-cycle.

LED vs halogen upgrade considerations

• Headlights and main DRL: These are LED modules from the factory on 2023 Forester and are not user-upgradable by a simple bulb swap. Aftermarket LED or HID conversions are not applicable unless you replace the entire headlamp assembly.
• Turn signals (7440/7444NA): Swapping to LED will cause hyperflash unless you add load resistors (about 6Ω, 50W per side) or a CANBUS-compatible LED designed to mimic load. Use amber LEDs for compliance and clarity.
• Reverse (921) and license plate (168/194): These usually do not trigger bulb-out warnings, but LEDs are polarity sensitive—flip the bulb if it doesn’t light. Choose models with built-in CANBUS if you experience flicker.
• Fog lights: If you have halogen H16 fogs and want LED, use quality, compact emitters that maintain the correct cutoff and do not foul the dust cap. Avoid oversized heat-sink styles that interfere with splash shields.
• Interior (map/dome): LED upgrades are straightforward. Pick warm white (4000–4500K) to avoid harsh glare, and low-profile panels for the festoon to prevent lens hotspots.

How to replace each bulb

• Front turn signal (7440/7444NA): Open hood, access the rear of the headlamp. Rotate the signal socket counterclockwise and pull out. Swap bulb and test hazards before reassembly.
• Fog light (H16 halogen if equipped): Turn the wheel outward, remove a few clips in the front fender liner to reach the fog housing. Twist the bulb socket out; avoid touching glass.
• Reverse (921): Open liftgate. Pop off the small service cover on the inside of the gate near the lamp. Twist the socket out, replace bulb, and test in reverse with the parking brake set.
• Rear turn signal (7440/7444NA): Open cargo area. Remove two screws/bolts on the outboard tail lamp and pull the lamp straight back to release clips, or use the interior access panel (varies by trim). Twist out the amber socket and replace.
• License plate (168/194): Use a trim tool to release the clear lens from the liftgate garnish. Twist the tiny socket out, swap bulb, and snap lens back in.
• Map lights (194): Carefully pry down the front map light lens. Pull the wedge bulb straight out. Use gloves to avoid fingerprints.
• Dome light (DE3175 31mm): Pry the center dome lens gently, release the festoon from spring clips, and fit the new 31mm lamp.

Non-serviceable LED modules

• Headlight low/high, DRL, tail/brake, and most side markers are sealed LED units on 2023 models. If inoperative, diagnose power/ground and BCM control first. Replacement typically requires the full assembly.

Common lighting issues for this generation

• Hyperflash after LED turn-signal swaps: Normal without proper resistors or CANBUS LEDs. Mount resistors to metal away from plastic.
• Moisture or condensation in headlamps/tails: Light fogging can be normal; persistent water droplets indicate a compromised vent or seal. Check caps and vents; replace the lamp if needed.
• License plate light corrosion: The liftgate location is exposed; sockets can corrode. Clean contacts and apply dielectric grease when replacing bulbs.
• Reverse light visibility: The single 921 can be dim. Upgrading to a quality LED 921 markedly improves camera clarity at night without errors.
• Interior rattle after map/dome service: Ensure all lens tabs and clips are fully seated to prevent noise.

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