This procedure covers the removal and replacement of the input speed sensor on the CVT transmission of a 2016-2021 Honda Civic with the 1.5L turbocharged engine.

Warnings

Tools required

Parts

• Input speed sensor (CVT) × 1 — 28820-5CK-003 or equivalent OEM
• Speed sensor O-ring × 1 — Use OEM specification

Fluids

• Honda DW-1 ATF — 1 qt

Preparation

1. Park vehicle on level ground and apply parking brake. Place wheel chocks behind rear wheels.
2. Allow engine and transmission to cool if vehicle was recently operated.
3. Raise and support the front of the vehicle on jack stands at proper lift points.
4. Remove driver's side front wheel for improved access (optional but recommended).
5. Remove plastic splash shield underneath driver's side if equipped to access sensor area.
6. Clean the area around the speed sensor to prevent contamination when opening the transmission.

Procedure

1. 1

   Locate the input speed sensor
   Identify the input speed sensor on the driver's side of the CVT transmission case. It is located near the left front axle area, mounted horizontally into the transmission housing with a single 10mm bolt. The sensor has an electrical connector attached to it.
2. 2

   Disconnect electrical connector
   Press the tab on the electrical connector and pull it straight off the input speed sensor. You may need to gently wiggle the connector while pulling. Use a plastic pick if the connector is difficult to release. Move the connector aside to provide clearance for sensor removal.
3. 3

   Position fluid catch pan
   Place a fluid catch pan directly beneath the input speed sensor location. Expect approximately 0.5 to 1 quart of transmission fluid to drain when the sensor is removed. Position shop towels around the area to catch any spray or drips.
4. 4

   Remove sensor mounting bolt
   Using a 10mm socket and ratchet, remove the single bolt securing the input speed sensor to the transmission case. Keep the bolt in a clean location for reinstallation.
   Torque spec

   Sensor Bolts10 Nm (8 lb-ft)
5. 5

   Extract the sensor
   Carefully pull the input speed sensor straight out of the transmission housing. It may require a slight twisting motion to break the O-ring seal. Transmission fluid will begin draining as soon as the sensor is removed. Allow fluid to drain into the catch pan for 1-2 minutes until flow stops.
6. 6

   Inspect and clean the bore
   Inspect the sensor bore in the transmission case for debris or metal particles. Wipe the mounting surface clean with a shop towel. Check the old sensor for physical damage or contamination. Inspect the old O-ring for damage, which may indicate the cause of sensor failure.
7. 7

   Prepare new sensor
   Remove the new input speed sensor from its packaging. Verify that a new O-ring is installed on the sensor body. If the O-ring is separate, install it into the groove on the sensor. Lightly coat the O-ring with clean Honda DW-1 ATF to aid installation and prevent damage.
8. 8

   Install new sensor
   Carefully insert the new input speed sensor straight into the transmission bore, ensuring the O-ring does not roll or pinch. Push the sensor in until it is fully seated against the transmission case. The sensor should sit flush with minimal resistance.
9. 9

   Install mounting bolt
   Thread the 10mm mounting bolt by hand to ensure it is not cross-threaded. Using a torque wrench, tighten the bolt to the specified torque of 10.0 Nm (8.0 lb-ft). Do not overtighten as this may damage the sensor housing or strip the aluminum threads in the transmission case.
   Torque spec

   Sensor Bolts10 Nm (8 lb-ft)
10. 10

    Reconnect electrical connector
    Push the electrical connector onto the new input speed sensor until it clicks into place. Gently tug on the connector to verify it is securely locked. Ensure the wiring is routed properly and not in contact with any hot or moving components.
11. 11

    Refill transmission fluid
    Locate the transmission dipstick (if equipped with dipstick) or the transmission fill plug on the passenger side of the transmission. Add Honda DW-1 ATF to replace the fluid lost during sensor removal, approximately 0.5 to 1.0 quart. On models without a dipstick, fluid must be added through the fill plug opening using a fluid pump or funnel with extension hose.
12. 12

    Check transmission fluid level
    With the engine running and transmission fluid at operating temperature (approximately 160-180°F), check the fluid level according to Honda's procedure. For vehicles with a dipstick, the level should be in the HOT range. For vehicles without a dipstick, fluid should be level with the bottom of the fill plug opening when warm. Add or remove fluid as necessary to achieve the correct level.

Reassembly

1. Reinstall the plastic splash shield underneath the driver's side if removed.
2. Reinstall the driver's side front wheel if removed and torque lug nuts to specification.
3. Lower the vehicle from jack stands and perform a final torque check on lug nuts.
4. Remove wheel chocks and tools from the work area.

Verification

• Start the engine and allow it to reach normal operating temperature while monitoring for fluid leaks around the input speed sensor.
• Shift through all transmission gear positions (P, R, N, D, S, L) while stationary to circulate fluid through the transmission.
• Using a scan tool, verify that the input speed sensor is providing a signal and there are no diagnostic trouble codes related to the speed sensor.
• Test drive the vehicle to confirm normal transmission operation and proper shift quality.
• After test drive, recheck transmission fluid level and top off if necessary.
• Perform a final inspection underneath the vehicle for any fluid leaks at the sensor location.

More procedures for this vehicle