This procedure covers the removal and replacement of the audio amplifier located in the cargo area of the 2016-2021 Honda Civic 1.5L Turbo.

Warnings

Tools required

Parts

• Audio amplifier assembly × 1 — Use OEM specification or verified aftermarket equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn ignition off and remove key/fob from vehicle
3. Disconnect negative battery terminal and secure cable away from battery post
4. Wait at least 3 minutes for system discharge
5. Clear cargo area of all items for access to left side trim panel
6. Have radio security code available if applicable to your trim level

Procedure

1. 1

   Remove cargo area left side trim panel
   Open the trunk/hatchback. Locate the left side cargo area trim panel. Use trim removal tools to carefully pry out the plastic clips securing the panel (typically 4-6 clips along the edges). Start from the rear edge and work forward. Gently pull the panel away from the body to release all clips. Set panel aside in a safe location.
2. 2

   Locate and access the amplifier
   With the trim panel removed, locate the amplifier mounted to the sheet metal behind where the panel was. The amplifier is a rectangular black or silver metal box approximately 8x6 inches. It will have a wiring harness connector and possibly a ground wire attached. Use a flashlight to identify all fasteners and connections.
3. 3

   Disconnect amplifier wiring harness
   Locate the main wiring harness connector on the amplifier. Press the locking tab on the connector and pull firmly to disconnect. The connector may be tight; wiggle gently while pulling if necessary. Do not pull on the wires themselves, only the connector body.
4. 4

   Remove ground wire if equipped
   If your amplifier has a separate ground wire connected with a bolt to the chassis, use a 10mm socket to remove the ground bolt. Note the exact location and ensure the ground contact surface is clean. Keep the ground wire attached to the amplifier for removal as an assembly.
   Torque spec

   Ground Bolt13 Nm (10 lb-ft)
5. 5

   Remove amplifier mounting bolts
   Using a 10mm socket, remove the amplifier mounting bolts (typically 3-4 bolts). Support the amplifier with one hand while removing the final bolt to prevent it from falling. Carefully pull the amplifier away from the mounting surface.
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
6. 6

   Remove amplifier from vehicle
   Once all bolts and connections are removed, carefully maneuver the amplifier out from behind any remaining brackets or wiring. Inspect the old amplifier for any signs of damage, corrosion, or overheating. Compare the new amplifier to the old unit to verify correct replacement part.
7. 7

   Install new amplifier
   Position the new amplifier into the mounting location, aligning the mounting holes with the studs or threaded holes in the body. If a ground wire is attached, route it to the ground point. Start all mounting bolts by hand to ensure proper thread engagement before tightening.
8. 8

   Torque amplifier mounting bolts
   Using a torque wrench, tighten the amplifier mounting bolts to specification in a cross-pattern to ensure even pressure. Verify the amplifier is secure and does not move when pushed gently.
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
9. 9

   Connect ground wire if equipped
   If the amplifier has a ground wire, ensure the contact surface on the chassis is clean and free of paint or corrosion. Position the ground terminal over the mounting point and install the ground bolt. Torque to specification.
   ℹ️A poor ground connection can cause audio system malfunction or noise; ensure metal-to-metal contact
   Torque spec

   Ground Bolt13 Nm (10 lb-ft)
10. 10

    Reconnect wiring harness
    Align the wiring harness connector with the amplifier connector and push firmly until you hear or feel a positive click. Tug gently on the connector to verify it is locked in place. Ensure no wires are pinched or stretched.
11. 11

    Reinstall cargo area trim panel
    Position the trim panel back into place, aligning all clip locations. Press firmly around all clip points until each clip snaps into place with an audible click. Verify the panel is flush and secure along all edges.
12. 12

    Reconnect battery
    Return to the battery and reconnect the negative terminal. Ensure the terminal is clean and seated fully on the battery post. Tighten the terminal bolt to specification.
    ⚠Do not overtighten battery terminal bolts as this can crack the terminal or damage the battery post
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Ensure all trim panels are fully seated with no gaps
2. Verify no tools or parts were left in the cargo area
3. If applicable, enter radio security code to restore audio system function

Verification

• Turn ignition to ON position (engine does not need to start)
• Turn on the audio system and verify it powers on without error messages
• Test all speakers to ensure amplifier is functioning correctly
• Adjust volume through full range and verify no distortion or cutting out
• Test audio sources (radio, Bluetooth, USB) to confirm all functions work properly
• If equipped with premium audio features (subwoofer, surround sound), verify all features are operational
• Check for any dashboard warning lights related to the audio system

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