engine

Crankshaft Position Sensor

for 2012 Ford F-150 3.5L V6 EcoBoost · 4WD

Difficulty

Moderate

Time

1.2 h

Tools

Steps

This procedure covers the removal and replacement of the crankshaft position sensor on the 2011-2014 Ford F-150 with the 3.5L EcoBoost engine.

Warnings

⚠Allow engine to cool completely before beginning work. The sensor is located near the transmission bellhousing and exhaust components.

⚠Disconnecting the battery will erase radio presets and may require drive cycle relearning for emissions monitors.

ℹ️The crankshaft position sensor is critical for engine operation. Ensure proper installation and connector engagement or the engine will not start.

Tools required

10mm socketEssential

Ratchet and extension setEssential

Torque wrench (5-25 Nm range)Essential

Pick or small flathead screwdriverEssential

Shop towelsEssential

Drain pan

Jack and jack standsEssential

Flashlight or work lightEssential

Vehicle ramps

Dielectric grease

Parts

Crankshaft position sensor × 1 — Motorcraft DY1094 or equivalent
O-ring seal (may be included with sensor) × 1 — Use OEM specification

Preparation

Ensure engine is cool to the touch
Park vehicle on level surface and engage parking brake
Disconnect negative battery cable and wait 5 minutes
Raise and secure the front of the vehicle on jack stands
Remove the plastic underbody shield/skid plate if equipped (typically 4-6 fasteners)
Allow adequate access to work from underneath the vehicle on the driver side

Procedure

1
Locate the crankshaft position sensor
From underneath the vehicle on the driver side, locate the crankshaft position sensor on the left side of the engine block near the transmission bellhousing. The sensor is positioned above the starter motor and points toward the crankshaft reluctor wheel. It has a single electrical connector with a gray or black housing.
2
Disconnect electrical connector
Press the red or gray locking tab on the electrical connector and carefully pull the connector straight off the sensor. If the connector is stuck due to corrosion, gently work it side to side while pulling. Do not pull on the wires themselves. Use a pick to carefully release the locking tab if needed.
3
Remove sensor mounting bolt
Using a 10mm socket with extension, remove the single bolt securing the crankshaft position sensor to the engine block. The bolt threads directly into the aluminum engine block. Keep track of this bolt as it can easily fall into the bellhousing area.
Torque spec
Crankshaft Position Sensor10 Nm (7 lb-ft)
4
Extract the sensor
Carefully pull the sensor straight out of its bore in the engine block. The sensor has an O-ring seal that may cause slight resistance. If the sensor is stuck, gently twist it while pulling to break the O-ring seal free. Do not pry against the engine block or sensor body as this may cause damage.
5
Inspect sensor bore and clean mounting surface
Inspect the sensor bore in the engine block for debris, metal shavings, or oil contamination. Wipe the mounting surface clean with a shop towel. Check for the old O-ring seal inside the bore and remove it if it remained in the block. Ensure no debris can fall into the engine during this process.
6
Prepare new sensor
Inspect the new crankshaft position sensor and verify it matches the old unit. Check that the new O-ring seal is properly seated in the groove on the sensor body. Optionally apply a light coating of clean engine oil to the O-ring to ease installation. Do not use any sealant or thread locker on the sensor or mounting bolt.
7
Install new sensor
Carefully insert the new sensor straight into the bore, ensuring the O-ring does not roll or pinch. Push the sensor firmly until it seats completely against the engine block mounting surface. The sensor should sit flush with no gap visible. Align the mounting hole with the threaded bore in the block.
8
Install and torque mounting bolt
Thread the mounting bolt by hand first to ensure proper thread engagement. Using a torque wrench, tighten the mounting bolt to 10.0 Nm (7.0 lb-ft). Do not overtighten as this can crack the sensor body or strip the aluminum threads in the engine block.
Torque spec
Crankshaft Position Sensor10 Nm (7 lb-ft)
9
Reconnect electrical connector
Push the electrical connector firmly onto the sensor until you hear or feel a distinct click indicating the locking tab has engaged. Gently tug on the connector to verify it is locked in place. Optionally apply a small amount of dielectric grease to the connector terminals for corrosion protection.
10
Reinstall underbody protection
Reinstall the plastic underbody shield or skid plate if previously removed. Ensure all fasteners are properly seated and tightened. Lower the vehicle from jack stands safely.
11
Reconnect battery and perform relearn
Reconnect the negative battery cable and tighten securely. The PCM may need to relearn idle and fuel trims. Start the engine and allow it to idle for at least 5 minutes. The engine should start normally and run smoothly without misfires or rough idle.

Reassembly

Ensure all electrical connectors are fully locked and secured
Verify the sensor mounting bolt is torqued to specification and not loose
Confirm underbody shields are reinstalled to protect components from road debris
Check that no tools or parts were left in the engine bay or under the vehicle

Verification

Start the engine and verify it starts normally without extended cranking
Confirm no check engine light illuminates related to crankshaft position sensor (P0335, P0336, P0338, P0339)
Allow engine to idle and verify smooth operation with no misfires
Use a scan tool to verify crankshaft position sensor signal is being read by the PCM
Test drive the vehicle to ensure normal engine operation under load and acceleration
Recheck for any oil leaks around the sensor installation area after test drive