Replace the third brake light (center high-mounted stop lamp) located in the rear spoiler or hatch glass area of the 2016-2021 Honda Civic.

Warnings

Tools required

Parts

• Third brake light assembly (center high-mounted stop lamp) × 1 — Honda OEM 34270-TBA-A01 or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn ignition off and remove key from vehicle
3. Allow any recently used lights to cool for at least 5 minutes to avoid burns
4. Identify your Civic body style (Sedan, Hatchback, or Coupe) as access procedures differ
5. Clean the area around the third brake light to prevent dirt from entering the vehicle during service

Procedure

1. 1

   Access the third brake light assembly from inside the vehicle
   For Sedan: Open the trunk and locate the third brake light assembly behind the rear shelf trim panel. For Hatchback: Open the rear hatch and locate the assembly behind the headliner near the rear glass. You may need to fold down rear seats for better access to trim fasteners.
2. 2

   Remove interior trim panel or cover
   Locate the plastic trim cover or fasteners securing access to the third brake light. For Sedan models, carefully pry up the rear shelf trim using a trim tool or flathead screwdriver wrapped in cloth. For Hatchback models, locate and remove the small trim panel or access cover near the hatch glass upper edge. Use gentle pressure to avoid breaking clips. Note the location of all clips and fasteners for reassembly.
3. 3

   Disconnect the electrical connector
   Locate the wiring harness connector attached to the back of the third brake light assembly. Press the tab or release mechanism on the connector and gently pull it straight away from the light assembly. Do not pull on the wires themselves. Inspect the connector for corrosion, damage, or moisture intrusion.
4. 4

   Remove mounting fasteners
   Locate the mounting screws or nuts securing the third brake light assembly (typically 2-4 fasteners depending on body style). Use a Phillips screwdriver or appropriate socket to remove these fasteners. Keep fasteners organized for reinstallation. Note that some models use plastic clips in addition to or instead of screws.
   Torque spec

   Cover Screws10 Nm (8 lb-ft)
5. 5

   Remove the old third brake light assembly
   Carefully pull the third brake light assembly away from its mounting location. For Sedan models, remove it from the inside toward the trunk. For Hatchback models, it may need to be pushed out toward the exterior or pulled inward depending on design. Work gently to avoid breaking mounting tabs or damaging the seal/gasket. Inspect the gasket or seal for damage.
6. 6

   Prepare and install the new assembly
   Compare the new third brake light assembly with the old unit to verify correct part. Check that any gasket or seal is properly positioned on the new assembly (replace gasket if it remained with the old unit or shows damage). Clean the mounting surface on the vehicle with a clean cloth to ensure proper seal. Position the new assembly into the mounting location, ensuring the gasket seats correctly and wiring can reach the connector without strain.
7. 7

   Install mounting fasteners
   Install the mounting screws or nuts and tighten them evenly in a cross-pattern to ensure even pressure on the gasket. If using torque specifications for cover screws, apply 10.0 Nm (8.0 lb-ft). Do not overtighten as this can crack the plastic housing or distort the seal. Ensure the assembly sits flush and the seal is compressed evenly all around.
   Torque spec

   Cover Screws10 Nm (8 lb-ft)
8. 8

   Reconnect electrical connector
   Plug the wiring harness connector firmly into the new third brake light assembly until you hear or feel it click into place. Gently tug on the connector to verify it is fully seated and locked. Ensure no wires are pinched or under stress.
9. 9

   Test brake light operation
   Before reinstalling trim panels, turn the ignition to ON position (engine does not need to run). Have an assistant press the brake pedal while you observe the third brake light from outside the vehicle, or use a mirror to check function yourself. Verify the light illuminates brightly and consistently. If light does not work, verify connector is fully seated and check for blown fuses before proceeding.
   ⚠️DO NOT reinstall trim panels or drive the vehicle if the third brake light does not illuminate properly. This creates a serious safety hazard and rear-end collision risk.
10. 10

    Reinstall interior trim panels
    Once brake light function is verified, reinstall the interior trim cover or panel. Align all clips carefully and press firmly until each clip seats with an audible snap. Ensure trim sits flush and does not rattle. For rear shelf trim, verify it does not interfere with trunk closing.

Reassembly

1. Ensure all trim panels are securely fastened and properly aligned
2. Verify no tools or parts were left in the trunk or hatch area
3. Close trunk or hatch and verify proper closure and alignment

Verification

• With ignition ON, have an assistant press the brake pedal while you observe all three brake lights (left, right, and center) from behind the vehicle
• Verify the third brake light illuminates immediately when brake pedal is pressed and turns off when pedal is released
• Check for proper seal by inspecting for light gaps around the assembly perimeter from outside the vehicle
• Verify no moisture can enter by visual inspection of seal compression
• Take a short test drive and verify brake lights function normally, have assistant confirm or check lights in reflection of nearby surfaces
• After 24-48 hours, inspect the assembly area for any water intrusion, especially after rain or car wash

More procedures for this vehicle