2018 Toyota Tundra Bulb Sizes

Quick Reference

The 2018 Toyota Tundra is a popular full-size truck known for its reliability and capability. When it comes to lighting, the Tundra offers a mix of traditional halogen and modern LED options depending on the trim level. Understanding the specific bulb sizes for your Tundra is crucial whether you're replacing a burnt-out bulb or considering an upgrade.

For the 2018 model year, most Tundra trims came standard with halogen headlights. This means H11 bulbs for the low beams and 9005 bulbs for the high beams. However, higher trims, such as the Platinum and 1794 Edition, might have come equipped with OEM LED low beam headlights, which are not designed for bulb replacement but rather as an integrated unit. The fog lights across the board typically use an H16 halogen bulb.

Daytime Running Lights (DRL) for the 2018 Tundra can vary. Some configurations use the high beam bulbs at a reduced wattage for DRL functionality, while higher trims with LED headlights often have integrated LED DRL strips that are part of the headlight assembly.

Interior lighting, including dome and map lights, generally feature incandescent bulbs. The dome light typically uses a DE3175 bulb, while the map lights utilize 168 bulbs. The license plate lights are also commonly 168 bulbs, and the various side markers (front and rear) also use 168.

LED vs Halogen Upgrade Considerations

Upgrading your 2018 Toyota Tundra's lighting from halogen to LED can significantly improve visibility and modernize its appearance. However, there are several factors to consider before making the switch.

CANBUS Errors: Many modern vehicles, including the 2018 Tundra, utilize a CANBUS (Controller Area Network Bus) system that monitors electrical circuits. LED bulbs draw less power than their halogen counterparts, which can sometimes trigger "bulb out" warnings or hyper-flashing (rapid blinking) in the turn signals because the CANBUS system interprets the lower power draw as a burnt-out bulb. To prevent these errors, you might need to install CANBUS-compatible LED bulbs or inline resistors.

Adapters Needed: While many aftermarket LED bulbs are designed for "plug-and-play" installation into existing halogen sockets, some may require additional adapters or modifications to fit properly and ensure a secure connection. This is particularly true for headlight upgrades where the LED bulb's heatsink or fan might interfere with the dust cap.

Beam Pattern: The reflector housing designed for a halogen bulb may not perfectly scatter the light from an LED bulb, potentially leading to a scattered beam pattern with hot spots and dark areas. This can reduce effective illumination and even blind oncoming drivers. Look for LED bulbs specifically designed to mimic the filament placement of their halogen equivalents to ensure a proper beam pattern.

How to Replace Each Bulb (Short Tips per Location)

Low Beam Headlight (H11): Access is usually from behind the headlight assembly in the engine bay. Twist counter-clockwise to remove, unplug, and replace.

High Beam Headlight (9005): Similar to the low beams, access is from the engine bay. Twist counter-clockwise to remove.

Fog Light (H16): Often accessed from underneath the front bumper or by removing fender liner screws. Twist and pull to remove.

Front Turn Signal (4157NAK): Typically accessed by reaching behind the headlight assembly or sometimes by removing the headlight housing itself. Twist to remove the socket.

Rear Turn Signal, Brake Light, Tail Light (3157): These are usually accessed by removing the tail light assembly from the exterior of the truck. Unbolt the assembly, pull it out, twist the bulb sockets, and replace.

Reverse Light (921): Also located within the tail light assembly. Follow the same procedure as above.

License Plate Light (168): Usually involves removing a small cover or screws near the license plate to access the bulb socket. Twist to remove.

Front and Rear Side Marker (168): These small bulbs are often integrated into larger assemblies or have small covers. Access can vary but typically involves twisting out the socket.

Dome Light (DE3175): Carefully pry open the clear lens cover to access the bulb. Usually a "festoon" style bulb that clips in.

Map Lights (168): Similar to the dome light, carefully pry off the lens to access the push-in bulb.

Always consult your owner's manual for specific instructions and diagrams for your Tundra model.

Common Lighting Issues for This Generation

While the 2018 Toyota Tundra is a robust vehicle, some common lighting issues, particularly with halogen systems, may arise.

Premature Halogen Bulb Failure: Some owners report that halogen headlight and fog light bulbs can have a shorter lifespan than expected. This can be due to vibrations, voltage fluctuations, or simply manufacturing tolerances. Keeping spare bulbs on hand is a good idea.

Corroded Sockets: Over time, moisture and dirt can lead to corrosion in bulb sockets, especially for exterior lights. This can cause intermittent bulb operation or complete failure. Cleaning the contacts with electrical contact cleaner or replacing the socket can resolve this.

DRL Malfunctions: If your Tundra uses the high beams for DRLs, issues with the high beam bulb or the DRL module could cause them to malfunction. If your vehicle has integrated LED DRLs, a failure typically means replacing the entire headlight assembly.

Trailer Wiring Issues: Owners who frequently tow may experience lighting issues related to the trailer wiring harness, such as blown fuses or incorrect bulb functionality on the trailer. Always check the trailer's wiring and connections first.

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