This procedure covers the removal and replacement of the Transmission Range Sensor (TRS) on a 2015-2020 Ford F-150 with 3.5L EcoBoost engine, which monitors transmission gear position and communicates with the PCM.

Warnings

Tools required

Parts

• Transmission Range Sensor × 1 — Motorcraft DY-1341 or equivalent
• Transmission Range Sensor O-ring × 1 — Use OEM specification

Fluids

• Motorcraft MERCON LV ATF — 1 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Chock rear wheels for additional safety
3. Allow transmission to cool to ambient temperature if vehicle was recently driven
4. Disconnect negative battery terminal and wait 2 minutes for system discharge
5. Raise vehicle on lift or support securely on jack stands at manufacturer lift points
6. Remove plastic transmission bellhousing cover if equipped for better access

Procedure

1. 1

   Locate Transmission Range Sensor
   From underneath the vehicle, locate the TRS on the driver's side of the 10R80 transmission case, near the manual shift lever. The sensor is mounted with two bolts and has an electrical connector on top. Use a work light for better visibility in the confined space.
2. 2

   Disconnect Electrical Connector
   Press the locking tab on the TRS electrical connector and carefully pull the connector straight off the sensor. Do not pull on the wires. If the connector is stuck, use a small flathead screwdriver to gently release the locking tab while pulling.
3. 3

   Position Drain Pan
   Place a small drain pan directly below the TRS mounting location. Expect approximately 4-8 ounces of transmission fluid to drain when the sensor is removed. Keep shop towels handy to catch any fluid that misses the pan.
4. 4

   Remove Sensor Mounting Bolts
   Using a 10mm socket, remove the two bolts securing the TRS to the transmission case. Support the sensor with your hand as you remove the second bolt to prevent it from falling. Keep bolts in a clean location for inspection and reuse if threads are in good condition.
   Torque spec

   Sensor Bolts12 Nm (9 lb-ft)
5. 5

   Remove Transmission Range Sensor
   Carefully pull the TRS straight out from the transmission case. Do not twist or rock the sensor excessively as this may damage the internal detent mechanism. Allow residual fluid to drain into the pan. Inspect the old O-ring on the sensor body for damage or wear.
6. 6

   Clean Mounting Surface
   Clean the TRS mounting surface on the transmission case with a lint-free shop towel. Remove any debris, old O-ring material, or metal particles. Ensure the mounting surface is completely dry before installing the new sensor. Inspect the mounting bore for any damage or scoring.
7. 7

   Prepare New Sensor
   Remove the new TRS from packaging and verify it matches the old unit. Install the new O-ring onto the sensor body if not pre-installed. Lightly lubricate the O-ring with clean MERCON LV ATF to ease installation and prevent O-ring damage. Do not use petroleum-based lubricants.
8. 8

   Install New Transmission Range Sensor
   Align the TRS with the mounting bore, ensuring the sensor shaft engages properly with the internal detent mechanism. The sensor should slide in smoothly with light hand pressure. Do not force it. Verify the sensor is fully seated against the transmission case before proceeding.
9. 9

   Install and Torque Mounting Bolts
   Hand-start both TRS mounting bolts to ensure proper thread engagement. Tighten bolts in an alternating pattern (first one bolt partially, then the other, then back to torque spec) to ensure even seating. Use a torque wrench to tighten both bolts to specification.
   Torque spec

   Sensor Bolts12 Nm (9 lb-ft)
10. 10

    Reconnect Electrical Connector
    Push the electrical connector onto the TRS until you hear and feel a positive click indicating the locking tab has engaged. Gently tug on the connector to verify it is securely locked. Ensure no wire strain or rubbing against sharp edges.
11. 11

    Check and Top Off Transmission Fluid
    Check the transmission fluid level using the dipstick or fluid check procedure for your transmission type. Add MERCON LV ATF as needed to compensate for fluid lost during sensor removal. Do not overfill. Typically 0.5-1.0 quart will be sufficient.
12. 12

    Reinstall Underbody Components
    Reinstall the transmission bellhousing cover if it was removed. Verify all tools and shop towels have been removed from underneath the vehicle. Lower the vehicle to the ground.
13. 13

    Reconnect Battery and Clear Codes
    Reconnect the negative battery terminal. Use an OBD-II scanner to clear any stored DTCs related to the TRS. Record any other codes present that may require attention.

Reassembly

1. Ensure all electrical connections are secure and properly routed away from heat sources
2. Verify transmission fluid level is within normal range on dipstick or via fluid check procedure
3. Double-check that both TRS mounting bolts are torqued to specification
4. Confirm parking brake is released before test drive

Verification

• With engine running and foot on brake, verify that all gear positions display correctly on the instrument cluster as you shift through P-R-N-D-S-L
• Perform a test drive and verify smooth shifting through all gears with no delay or harsh engagement
• Verify reverse lights illuminate when transmission is shifted into reverse
• Use OBD-II scanner to confirm no TRS-related DTCs are present (P0705, P0708, P0709, etc.)
• Verify the engine will only start in Park and Neutral positions
• Check for any transmission fluid leaks around the TRS after test drive

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