Crankshaft Position Sensor
2021 Ford F-150 · 3.5L V6 EcoBoost
Sensor Type
hall-effect
Waveform Type
dc-square
Location
Right side of engine block, above the starter motor, reading a 36-tooth reluctor wheel with one missing tooth (36-1 pattern) on the crankshaft
Pins
3-pin connector
Idle Frequency
50 Hz
Timebase
20ms/div
Voltage Scale
2V/div
Trigger
2.5V, rising edge
Wiring
Gray/Yellow (signal), Black/White (ground), Orange/Blue (12V power supply)
Expected Voltage Range
At Idle
0.2V to 4.8V
At Higher RPM
0.1V to 5V
Expected Pattern
36-1 tooth pattern with square wave pulses, one missing tooth gap per crankshaft revolution for synchronization
Known-Good Waveform
Clean square wave transitions between 0.2V and 4.8V at idle (approximately 600 RPM), with 35 evenly-spaced pulses followed by one distinct gap representing the missing tooth. Pulse width decreases proportionally with RPM increase, but voltage levels remain consistent. Rise and fall times should be sharp, less than 1 microsecond.
Common Failure Patterns
Intermittent signal dropout or complete loss of square wave, may show erratic voltage fluctuations
Cause: Internal Hall-effect IC failure due to heat exposure from turbocharger proximity or oil contamination on sensor face
Rounded or sloped edges on square wave transitions, reduced voltage amplitude below 4V peak
Cause: Corroded connector terminals or damaged wiring harness, common where harness passes near exhaust components
Diagnostic Tips
On EcoBoost engines, verify oil cleanliness as timing chain wear can deposit metallic debris on the reluctor wheel. The sensor's proximity to the turbos makes heat-related failures common; check for oil weeping from the sensor seal which indicates bearing housing pressure issues.
Related Diagnostic Trouble Codes
P0335P0336P0337P0338P0339
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
Free, no signup. View all waveforms for this vehicle