This procedure covers the removal and replacement of the input speed sensor (turbine shaft speed sensor) on the 10R80 automatic transmission used in 2015-2020 Ford F-150 trucks with the 5.0L Coyote V8 engine.

Warnings

Tools required

Parts

• Transmission input speed sensor (TSS) × 1 — Use OEM Ford sensor or equivalent quality aftermarket
• Sensor O-ring seal × 1 — Often included with sensor assembly
• Motorcraft MERCON LV ATF × 2 — XT-10-QLVC

Fluids

• Motorcraft MERCON LV ATF — 2 qt

Preparation

1. Park vehicle on level surface and apply parking brake firmly
2. Place wheel chocks behind rear wheels
3. Allow transmission to cool completely if vehicle was recently driven (minimum 2 hours)
4. Raise front of vehicle to comfortable working height and support securely on jack stands at frame rails
5. Verify vehicle is stable before going underneath
6. Locate transmission input speed sensor on driver side of transmission case (approximately mid-body location)

Procedure

1. 1

   Disconnect battery negative terminal
   Disconnect the negative battery terminal to prevent any electrical shorts or fault codes during sensor replacement. Use a 10mm wrench to loosen the terminal clamp and move cable away from battery post.
2. 2

   Access sensor from underneath
   Position yourself under the driver side of the vehicle. The input speed sensor is located on the driver side of the transmission case, approximately at mid-body. It will have a single electrical connector and is secured by one 10mm bolt. Identify the sensor and ensure adequate clearance to access both the electrical connector and mounting bolt.
3. 3

   Disconnect electrical connector
   Press the release tab on the sensor electrical connector and carefully pull connector straight away from sensor. Do not twist or pull on wires. If connector is stubborn, spray with electrical contact cleaner and work gently to avoid damage. Inspect connector terminals for corrosion or damage.
   ⚠Do not pull on wires to disconnect connector. Use only the connector body to prevent wire damage.
4. 4

   Position drain pan
   Place a drain pan with at least 2 gallon capacity directly beneath the input speed sensor. Approximately 1-2 quarts of transmission fluid will drain when the sensor is removed. Position the pan to catch fluid that will flow from the sensor bore.
5. 5

   Remove sensor mounting bolt
   Using a 10mm socket with extension, remove the single mounting bolt securing the input speed sensor to the transmission case. Keep the bolt in a safe location for reinstallation or replacement.
6. 6

   Extract old sensor
   Carefully pull the sensor straight out of the transmission case bore. Fluid will begin draining immediately. Allow fluid to drain completely into the pan. Once drained, remove the old O-ring seal from the sensor (if not already separated) and inspect the sensor bore in the transmission case for debris or damage.
   ⚠Transmission fluid will flow out when sensor is removed. Ensure drain pan is properly positioned.
7. 7

   Clean sensor bore
   Wipe the sensor bore opening in the transmission case with a clean shop towel. Remove any debris, old seal material, or metal particles. The bore must be clean to ensure proper seal of the new sensor. Do not allow debris to enter the transmission case.
8. 8

   Prepare new sensor
   Remove new input speed sensor from packaging. Verify new O-ring seal is properly seated in the sensor groove. Lightly coat the O-ring with clean MERCON LV ATF to aid installation and prevent damage during insertion. Do not use petroleum-based lubricants.
9. 9

   Install new sensor
   Carefully insert the new sensor straight into the transmission case bore. Push firmly until the sensor mounting flange is flush against the transmission case. Do not cross-thread or force the sensor at an angle. The sensor should slide in smoothly with light resistance from the O-ring seal.
10. 10

    Install and torque mounting bolt
    Install the sensor mounting bolt and hand-tighten. Using a torque wrench, tighten the sensor bolt to specification. Ensure sensor remains properly seated and flush with case during tightening.
    Torque spec

    Sensor Bolts14 Nm (10 lb-ft)
11. 11

    Reconnect electrical connector
    Push the electrical connector onto the new sensor until it clicks into place. Tug gently on the connector to verify it is fully locked. Ensure connector weather seal is properly seated to prevent moisture intrusion.
12. 12

    Refill transmission fluid
    Locate the transmission fill plug on the side of the transmission case. Remove the fill plug and use a fluid transfer pump to add approximately 2 quarts of Motorcraft MERCON LV ATF (or the amount that was drained). Fill until fluid begins to trickle from the fill hole with transmission at operating temperature, or slightly below fill hole when cold. Reinstall fill plug and torque to specification.
    ℹ️Final fluid level must be verified with transmission at operating temperature (160-180°F) on level ground with engine running in Park.
    Torque spec

    Fill Plug42 Nm (31 lb-ft)
13. 13

    Reconnect battery
    Reconnect the negative battery terminal and tighten securely with 10mm wrench. Ensure good connection to prevent voltage drop or starting issues.

Reassembly

1. Ensure all electrical connections are properly locked and weather seals are seated
2. Verify drain pan has been removed from under vehicle before lowering
3. Lower vehicle carefully from jack stands
4. Dispose of used transmission fluid properly at a recycling center or parts store

Verification

• Start engine and verify no transmission fluid leaks from sensor location
• Allow transmission to reach operating temperature (160-180°F), then verify proper fluid level at fill plug with engine running in Park on level ground
• Using a scan tool, verify input speed sensor is reading properly and providing data to PCM (sensor should show 0 RPM in Park with engine running)
• Road test vehicle through all gears and verify smooth shifting with no transmission fault codes
• Check for diagnostic trouble codes; clear any codes that were set during battery disconnection
• Recheck fluid level after road test and top off if necessary
• Inspect sensor area for leaks after road test

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