Complete replacement of the engine bay fuse box assembly on a 2016-2021 Honda Civic 1.5L Turbo, including removal of battery, disconnection of electrical harnesses, and installation of new fuse box.

Warnings

Tools required

Parts

• Engine bay fuse box assembly × 1 — 38200-TBA-A01 or equivalent OEM
• Battery terminal protector spray × 1 — Use OEM specification
• Dielectric grease × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and engage parking brake
2. Turn ignition off and remove key from vehicle
3. Allow engine to cool completely if recently driven
4. Open hood and secure with prop rod
5. Take photos of fuse box from multiple angles for reference
6. Document which fuses are installed and their locations (especially if non-standard configuration)
7. Gather all tools and parts before beginning

Procedure

1. 1

   Disconnect and remove battery
   Using a 10mm socket, loosen the negative battery terminal bolt first, then remove the cable and secure it away from the battery post. Repeat for positive terminal. Remove the battery hold-down bracket (10mm bolt) and carefully lift the battery from the tray. Set battery on a non-conductive surface away from work area.
   ⚠️Always disconnect negative terminal first to prevent short circuits
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
2. 2

   Remove fuse box cover and document fuse layout
   Release the clips securing the fuse box cover by pressing tabs and lifting upward. Remove cover completely. Take a clear photo of the fuse and relay layout. If replacing with new box, transfer all fuses and relays to matching positions in new unit, or note which positions contain fuses for reinstallation.
3. 3

   Disconnect main harness connectors
   Locate all electrical connectors on the underside and sides of the fuse box (typically 3-5 large multi-pin connectors). Press release tabs while gently pulling connectors straight out. Do not twist or rock connectors excessively. Mark or photograph each connector's orientation and position. Some connectors have secondary locks that must be lifted before main tab can be released.
   ⚠Large connectors may be very tight - wiggle gently while pulling to avoid damaging pins
4. 4

   Remove battery positive cable connection
   Locate the large positive battery cable terminal bolted directly to the fuse box (usually a red cable with protective cover). Remove protective cover if present. Using a 10mm or 12mm socket (verify size), remove the terminal bolt completely. Carefully move the cable aside to prevent accidental grounding.
   ⚠This cable carries full battery current when connected - ensure battery is disconnected before proceeding
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
5. 5

   Disconnect ground connections
   Identify ground strap(s) connected to the fuse box mounting area (typically black cable(s) bolted to body or fuse box bracket). Using appropriate socket (typically 10mm or 12mm), remove ground strap bolts and move straps aside. Clean mating surfaces with wire brush to ensure good contact during reassembly.
   Torque spec

   Ground Bolt13 Nm (10 lb-ft)

   Ground Strap Bolts12 Nm (9 lb-ft)
6. 6

   Remove air intake duct if obstructing access
   If the air intake duct interferes with fuse box removal, loosen the hose clamp at the throttle body end using flathead screwdriver. Disconnect any vacuum lines or sensor connectors attached to the duct. Lift duct away from engine bay and set aside.
7. 7

   Remove fuse box mounting bolts
   Locate the fuse box mounting bolts (typically 3-4 bolts securing box to inner fender well or body). Using 10mm or 12mm socket with extension as needed, remove all mounting bolts. Keep bolts organized by location. Check for any hidden bolts underneath or behind the fuse box.
   ⚠Support fuse box with one hand while removing final bolt to prevent dropping
   Torque spec

   Module Mounting Bolts8 Nm (6 lb-ft)
8. 8

   Remove fuse box from vehicle
   With all connections and mounting bolts removed, carefully lift and maneuver the fuse box out of its mounting location. May require tilting or rotating to clear surrounding components. Inspect mounting area for corrosion or damage. Clean mounting surfaces as needed.
9. 9

   Prepare and position new fuse box
   Transfer all fuses and relays from old box to new box in exact same positions (use photos for reference). Apply light coat of dielectric grease to large connector seals. Position new fuse box into mounting location, ensuring all harness connectors can reach without strain. Align mounting holes with body.
10. 10

    Install fuse box mounting bolts
    Start all mounting bolts by hand to ensure proper threading. Using torque wrench and appropriate socket, tighten mounting bolts to specification in a cross-pattern to ensure even seating. Verify fuse box is secure and does not shift when lightly pulled.
    Torque spec

    Module Mounting Bolts8 Nm (6 lb-ft)
11. 11

    Reconnect ground connections
    Reattach ground strap(s) to fuse box area. Ensure mating surfaces are clean and free of paint or corrosion for good electrical contact. Install bolts and tighten to specification using torque wrench.
    ⚠Poor ground connections can cause multiple electrical issues - ensure clean metal-to-metal contact
    Torque spec

    Ground Bolt13 Nm (10 lb-ft)

    Ground Strap Bolts12 Nm (9 lb-ft)
12. 12

    Reconnect battery positive cable
    Position battery positive cable terminal onto fuse box connection post. Install terminal bolt and tighten to specification. Do not overtighten as this can strip threads or crack housing. Reinstall protective cover if equipped.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)
13. 13

    Reconnect main harness connectors
    Using photos as reference, reconnect all harness connectors to fuse box in correct positions. Push each connector firmly until it clicks into place. Engage any secondary locks. Gently tug on each connector to verify it is fully seated and locked.
    ⚠Verify each connector is in correct position - mismatched connectors can damage modules
14. 14

    Reinstall battery and connect terminals
    Place battery back into tray ensuring it seats fully. Install hold-down bracket and tighten bolt. Clean battery terminals with wire brush if corroded. Connect positive terminal first, then negative terminal. Tighten terminal bolts to specification - do not overtighten. Apply terminal protector spray to prevent corrosion.
    ⚠Connect positive terminal first during installation, opposite of removal order
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)
15. 15

    Reinstall components and fuse box cover
    If air intake duct was removed, reinstall it by connecting to throttle body and tightening hose clamp. Reconnect any vacuum lines or sensors. Install fuse box cover by aligning tabs and pressing down until clips engage. Verify cover is fully seated.

Reassembly

1. Double-check that all electrical connectors are fully seated and locked
2. Verify battery terminals are tight and corrosion-protected
3. Ensure no tools or parts are left in engine bay
4. Confirm fuse box cover is properly installed with all clips engaged

Verification

• Turn ignition to ON position (do not start) - verify dash lights illuminate normally with no unusual warning lights
• Check that all electrical accessories function: headlights, turn signals, wipers, windows, radio, climate control
• Start engine and verify it runs normally with no warning lights
• Test operation of all safety systems including horn and brake lights
• Check for proper charging system operation (battery light should extinguish after starting)
• Perform power window auto-up/down initialization if windows do not auto-up: roll window fully down, then hold up switch for 2 seconds after window reaches top
• Reset clock and radio presets as needed
• Scan for diagnostic trouble codes with OBD-II scanner to verify no electrical faults are present

More procedures for this vehicle