This procedure covers the removal and replacement of the starter solenoid on the 2016-2021 Honda Civic 1.5L Turbo, which is typically serviced as part of the complete starter motor assembly.

Warnings

Tools required

Parts

• Starter motor assembly with integrated solenoid × 1 — Use OEM Honda or equivalent
• Starter mounting bolt anti-seize compound × 1 — Use high-temperature anti-seize

Preparation

1. Park vehicle on a level surface and apply parking brake
2. Place wheel chocks behind rear wheels
3. Allow engine to cool completely if recently operated (minimum 2 hours)
4. Ensure you have the radio security code if equipped, as battery disconnection will reset the radio
5. Gather all tools and parts before beginning work

Procedure

1. 1

   Disconnect battery negative terminal
   Open the hood and locate the battery in the engine bay. Using a 10mm wrench, loosen the negative (-) battery terminal bolt. Remove the negative cable and position it away from the battery terminal to prevent accidental contact. Wait at least 3 minutes for electrical systems to discharge.
   Torque spec

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

   Raise and support vehicle
   Lift the front of the vehicle using a floor jack at the designated front jacking point. Support the vehicle securely on jack stands positioned under the frame rails. The starter is accessible from underneath on this model. Ensure the vehicle is stable before working underneath.
3. 3

   Remove engine undercover
   Locate and remove the plastic engine undercover/splash shield using a 10mm socket. There are typically 8-10 bolts and several plastic clips securing the undercover. Set aside the hardware and undercover in a safe location.
4. 4

   Locate the starter motor
   From underneath the vehicle, locate the starter motor on the transmission bell housing, positioned below and behind the engine block near the firewall. The starter is cylindrical and has electrical connections on the solenoid end. Use a flashlight to identify the mounting bolts and electrical connections.
5. 5

   Disconnect starter electrical connections
   Identify the two electrical connections on the starter solenoid: the main battery cable (larger wire with 12mm nut) and the signal wire connector (smaller push-on connector). First, remove the 12mm nut securing the battery cable to the solenoid stud using a 12mm socket. Pull the cable terminal straight off the stud. Then disconnect the smaller signal wire connector by pressing the release tab and pulling it off the solenoid terminal.
   ⚠Even with the battery disconnected, the battery cable at the starter carries residual charge. Do not allow it to contact ground
   Torque spec

   Battery Terminal Bolts6 Nm (4 lb-ft)
6. 6

   Remove upper starter mounting bolt
   Locate the upper starter mounting bolt which secures the starter to the transmission bell housing. This bolt is accessed from above or below depending on surrounding components. Use a 14mm socket with extension to remove this bolt. You may need to apply penetrating oil if the bolt is corroded. Keep this bolt separate as it may differ from the lower bolt.
   Torque spec

   Mounting Bolts32 Nm (24 lb-ft)
7. 7

   Remove lower starter mounting bolt
   Using a 14mm socket and extension, remove the lower starter mounting bolt from below the vehicle. This bolt is more easily accessible from underneath. Apply penetrating oil if needed. Once the bolt is loosened, support the starter motor weight with one hand as you remove the bolt completely.
   ⚠Support the starter motor before removing the final bolt. The unit weighs approximately 8-10 lbs and can drop suddenly
   Torque spec

   Mounting Bolts32 Nm (24 lb-ft)
8. 8

   Remove starter motor assembly
   With both mounting bolts removed and electrical connections detached, carefully maneuver the starter motor out of its mounting position. You may need to rotate or angle the starter to clear surrounding components. Lower the starter down and out from underneath the vehicle. Inspect the mounting surface on the bell housing for debris or damage.
9. 9

   Prepare new starter assembly
   Unbox the new starter motor assembly. Verify that the mounting bolt holes align with the original unit and that the electrical terminal configuration matches. Apply a thin coat of anti-seize compound to the threads of the mounting bolts (not the bolt heads). Ensure the starter drive gear rotates freely and the solenoid plunger moves smoothly when pressed.
10. 10

    Install new starter motor
    Position the new starter motor assembly into the mounting location on the transmission bell housing. Align the mounting holes with the threaded holes in the bell housing. You may need to rotate the starter to achieve proper alignment. Insert the lower mounting bolt first and thread it in by hand several turns, but do not tighten yet.
11. 11

    Install and torque mounting bolts
    Insert the upper mounting bolt and thread it in by hand. Once both bolts are started, tighten them evenly in an alternating pattern using a 14mm socket. Final torque both starter mounting bolts to 45 Nm (33 lb-ft) using a torque wrench. Verify the starter is seated flush against the bell housing with no gaps.
    Torque spec

    Mounting Bolts32 Nm (24 lb-ft)
12. 12

    Reconnect electrical connections
    Reconnect the starter electrical connections in reverse order of removal. First, push the small signal wire connector onto the solenoid terminal until it clicks into place. Then place the battery cable terminal onto the solenoid stud and secure it with the 12mm nut. Torque the terminal nut to 6 Nm (5 lb-ft). Ensure both connections are secure and properly seated.
    Torque spec

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

    Reinstall engine undercover
    Reinstall the plastic engine undercover/splash shield using the original mounting bolts and clips. Ensure all fasteners are properly seated and tightened. Verify the undercover is secure and not interfering with any moving components.
14. 14

    Lower vehicle and reconnect battery
    Carefully lower the vehicle from the jack stands and remove the jack. Reconnect the negative battery terminal to the battery post and tighten the terminal bolt to 6 Nm (4 lb-ft) using a 10mm wrench. Do not overtighten the battery terminal bolt as this can damage the terminal or battery post.
    Torque spec

    Battery Terminal Bolts6 Nm (4 lb-ft)

Reassembly

1. Ensure all electrical connections at the starter are secure and properly routed
2. Verify the engine undercover is properly installed with all fasteners tight
3. Double-check that no tools or parts were left in the engine bay or under the vehicle
4. If radio security code is required, have it ready for entry after battery reconnection

Verification

• Turn the ignition key to the ON position (do not start) and verify that dashboard warning lights illuminate normally
• Attempt to start the engine. The starter should engage immediately with a smooth cranking sound. The engine should start normally
• Listen for any unusual grinding, clicking, or whining noises from the starter during cranking
• Start the engine 3-4 times from cold to verify consistent starter operation
• Check for any electrical burning smells or smoke from the starter area during operation
• Verify that the starter disengages properly after the engine starts (no continued grinding noise)
• Inspect underneath the vehicle for any fluid leaks that may have resulted from the repair
• Reset the radio and clock as needed after battery disconnection

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