This procedure covers removal and replacement of the starter motor on a 2016-2021 Honda Civic with the 1.5L turbocharged engine, including disconnecting the battery, accessing the starter from underneath, and proper electrical reconnection.

Warnings

Tools required

Parts

• Starter motor assembly × 1 — OEM: 31200-5AA-A51 or equivalent

Preparation

1. Park vehicle on level surface and engage parking brake
2. Place wheel chocks behind rear wheels
3. Turn ignition to OFF position and remove key/fob from vehicle
4. Allow engine to cool if recently operated
5. Gather all tools and new starter motor
6. Raise front of vehicle and support securely on jack stands under manufacturer-specified jacking points

Procedure

1. 1

   Disconnect battery negative terminal
   Open the hood and locate the battery in the engine bay. Use a 10mm wrench to loosen the negative (-) battery cable nut. Remove the cable from the terminal and secure it away from the battery post to prevent accidental contact. Wait at least 3 minutes before proceeding.
2. 2

   Access starter from underneath
   Position yourself under the front of the vehicle. The starter is located on the passenger side (right side) of the engine, between the engine block and transmission bellhousing. You may need to remove the plastic engine undershield if equipped by removing the push clips and 10mm bolts.
3. 3

   Remove heat shield (if equipped)
   Some models have a heat shield covering the starter. If present, remove the heat shield mounting bolts using a 10mm socket. Set the shield and bolts aside for reinstallation.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
4. 4

   Disconnect starter solenoid electrical connection
   Locate the electrical connector on the starter solenoid (smaller connector). Press the release tab and pull the connector straight off the solenoid terminal. Do not pull on the wiring harness.
5. 5

   Remove B+ cable from starter solenoid
   Using a 12mm socket, remove the nut securing the large battery positive (B+) cable to the starter solenoid. Carefully pull the cable terminal off the solenoid stud. Move the cable aside and secure it to prevent it from contacting other components.
   ⚠Although battery is disconnected, the B+ cable remains energized from the underhood fuse box. Ensure it does not contact ground.
   Torque spec

   Starter Solenoid Nut12 Nm (9 lb-ft)
6. 6

   Remove upper starter mounting bolt
   Locate the upper starter mounting bolt which threads into the transmission bellhousing. This bolt may be difficult to access. Use a 14mm socket with an extension to remove this bolt completely. Keep track of the bolt as it is different from the lower bolt.
   Torque spec

   Starter Mounting Bolts50 Nm (37 lb-ft)
7. 7

   Remove lower starter mounting bolt
   Locate and remove the lower starter mounting bolt using a 14mm socket. This is typically the longer bolt and may require a long extension to reach. Note the bolt length and position for reinstallation. Support the starter with one hand as you remove the final bolt.
   ⚠Support the starter motor before removing the last bolt to prevent it from falling. The starter weighs approximately 8-10 lbs.
   Torque spec

   Starter Mounting Bolts50 Nm (37 lb-ft)
8. 8

   Remove starter motor
   With both mounting bolts removed, carefully slide the starter forward (away from the transmission) to disengage it from the alignment dowel pins. Rotate and maneuver the starter as needed to clear the surrounding components and remove it from the vehicle. The nose of the starter must clear the flywheel/flexplate ring gear.
9. 9

   Inspect mounting area and prepare new starter
   Inspect the flywheel/flexplate ring gear teeth for damage or wear. Clean the starter mounting surface on the bellhousing with a wire brush if needed. Verify the alignment dowel pins are present and in good condition. Compare the new starter to the old unit to confirm correct application.
10. 10

    Install new starter motor
    Position the new starter and carefully guide it into place, ensuring the nose engages properly with the bellhousing opening and the starter gear clears the ring gear teeth. Align the starter with the dowel pins on the bellhousing. Hand-thread both mounting bolts to ensure proper alignment before tightening.
11. 11

    Torque starter mounting bolts
    Using a torque wrench and 14mm socket with extension, torque both starter mounting bolts to specification. The longer bolt (typically lower position) may require a longer extension to achieve proper access and torque wrench angle. Torque both bolts in a cross pattern if possible.
    Torque spec

    Starter Mounting Bolts50 Nm (37 lb-ft)
12. 12

    Reconnect B+ cable to solenoid
    Place the battery positive cable terminal onto the starter solenoid stud. Install the nut and torque to specification using a 12mm socket and torque wrench. Ensure the connection is clean and secure.
    Torque spec

    Starter Solenoid Nut12 Nm (9 lb-ft)
13. 13

    Reconnect solenoid electrical connector
    Push the electrical connector onto the solenoid terminal until it clicks securely into place. Verify the connector lock tab is fully engaged. Ensure no wires are pinched or in contact with hot or moving components.
14. 14

    Reinstall heat shield and undershield
    If a heat shield was removed, reinstall it and torque the mounting bolts to specification. Reinstall any engine undershield or splash guards that were removed, ensuring all clips and fasteners are properly secured.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
15. 15

    Reconnect battery and verify operation
    Lower the vehicle from jack stands. Reconnect the negative battery cable to the battery terminal and torque the cable nut to specification using a 10mm socket and torque wrench. Ensure the connection is tight and corrosion-free.

Reassembly

1. Ensure all electrical connections are secure and properly routed away from heat sources and moving parts
2. Verify no tools or parts were left in the engine bay or under the vehicle
3. Double-check that all mounting bolts are torqued to specification
4. Confirm engine undershield and any removed panels are properly reinstalled

Verification

• Turn the ignition to the ON position and verify all warning lights illuminate normally on the instrument cluster
• Ensure the transmission is in Park (automatic) or Neutral (manual)
• Attempt to start the engine - it should crank smoothly and start normally
• Listen for any unusual noises from the starter area during cranking
• Verify the starter disengages immediately after engine starts (no grinding noise)
• Turn the engine off and attempt one more cold start to confirm proper operation
• Check for any fluid leaks or loose connections in the work area
• Reset radio presets and clock if needed, as battery disconnection will clear these settings

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