This procedure covers the removal and replacement of the crankshaft position sensor on the 2021-2024 Ford F-150 with the 3.5L EcoBoost V6 engine.

Warnings

Tools required

Parts

• Crankshaft position sensor × 1 — Motorcraft DY1286 or equivalent
• Sensor O-ring seal × 1 — Usually included with sensor

Preparation

1. Ensure engine is completely cool
2. Park vehicle on level surface and engage parking brake
3. Disconnect negative battery cable to prevent accidental starter engagement
4. If recently driven, wait minimum 30 minutes for cooling
5. Raise and support front of vehicle on jack stands for better access (optional but recommended)
6. Remove passenger side front wheel for improved access if needed

Procedure

1. 1

   Access the sensor area
   From underneath the vehicle on the passenger side, locate the crankshaft position sensor mounted on the lower engine block between the engine and transmission bellhousing area. The sensor is positioned near the flywheel/flexplate and may require removal of heat shields or covers for access. Use a flashlight to clearly identify the sensor and its electrical connector.
2. 2

   Disconnect sensor electrical connector
   Locate the electrical connector on the crankshaft position sensor wiring harness. Press the locking tab and carefully pull the connector straight off the sensor. If the connector is difficult to remove, use a pick tool to release the locking mechanism. Inspect the connector terminals for corrosion or damage.
3. 3

   Remove wiring harness retainers
   Follow the sensor wiring harness and disconnect any retaining clips or brackets securing it to the engine block. This provides slack for sensor removal. Note the routing of the harness for proper reinstallation.
4. 4

   Remove crankshaft position sensor bolt
   Using a 10mm socket with extension, remove the single bolt securing the crankshaft position sensor to the engine block. Keep track of this bolt as it may have a specific shoulder design. If the bolt is difficult to access, a universal joint or swivel socket may be helpful.
   Torque spec

   Crankshaft Position Sensor10 Nm (7 lb-ft)
5. 5

   Extract the sensor
   Carefully pull the crankshaft position sensor straight out from the engine block. The sensor may be tight due to the O-ring seal. Gently twist while pulling if needed, but do not pry against the engine block. If sensor is seized, carefully work it back and forth to break the seal.
   ⚠Do not pry against the engine block surface as this can cause damage to the sealing surface.
6. 6

   Clean sensor bore
   Use a clean lint-free rag and brake cleaner to thoroughly clean the sensor bore in the engine block. Remove any oil residue, debris, or old O-ring material. Inspect the bore for damage or metal debris which could indicate internal engine problems. Ensure the bore is completely dry before installation.
7. 7

   Inspect old sensor
   Examine the removed sensor for damage, metal shavings on the tip, or oil contamination. Compare the old and new sensors to verify correct replacement part. Check that the new sensor includes a new O-ring seal.
8. 8

   Prepare new sensor
   Install the new O-ring seal onto the new crankshaft position sensor if not pre-installed. Lightly lubricate the O-ring with clean engine oil to ease installation and prevent damage. Do not use any sealant or thread locker on the sensor or mounting bolt.
9. 9

   Install new crankshaft position sensor
   Carefully insert the new sensor straight into the engine block bore, ensuring proper alignment. Push the sensor in by hand until it seats flush against the engine block mounting surface. Do not force the sensor or allow it to cock sideways during installation.
10. 10

    Install and torque sensor bolt
    Thread the sensor mounting bolt by hand to prevent cross-threading. Once hand-tight, use a torque wrench to tighten to specification. Ensure the sensor remains fully seated during tightening.
    Torque spec

    Crankshaft Position Sensor10 Nm (7 lb-ft)
11. 11

    Reconnect electrical connector
    Clean the electrical connector terminals with electrical contact cleaner if needed. Push the connector firmly onto the new sensor until you hear and feel the locking tab click into place. Gently tug on the connector to verify it is securely locked.
12. 12

    Secure wiring harness
    Route the sensor wiring harness according to the original path noted during removal. Reinstall all retaining clips and brackets to prevent the harness from contacting hot or moving components. Ensure adequate clearance from the exhaust system.
13. 13

    Reconnect battery
    Reconnect the negative battery cable and tighten securely. If the front wheel was removed, reinstall it and torque lug nuts to specification. Lower the vehicle from jack stands if raised.

Reassembly

1. Ensure all electrical connections are secure and properly locked
2. Verify wiring harness is properly routed and secured away from heat and moving parts
3. Confirm sensor mounting bolt is torqued to specification
4. Reinstall any heat shields or covers removed during access

Verification

• Turn ignition key to ON position (do not start) and verify no check engine light for crankshaft position sensor codes
• Start the engine and listen for smooth cranking and immediate start (sensor signal present)
• Allow engine to idle for 2-3 minutes and verify stable idle with no misfire or rough running
• Use a scan tool to verify the crankshaft position sensor is providing RPM signal to the ECM
• Test drive vehicle and confirm normal acceleration and performance with no check engine light
• Recheck for any fluid leaks around the sensor area after test drive

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