Vehicle Speed Sensor
2015 Ford F-150 · 5.0L V8 Coyote
Sensor Type
hall-effect
Waveform Type
dc-square
Location
On rear of transmission tail housing (2WD) or on transfer case output (4WD), reading tone ring on output shaft
Pins
3-pin connector
Timebase
20ms/div at 30mph, 10ms/div at 60mph
Voltage Scale
5V/div
Trigger
6V, rising edge
Wiring
White/Purple (signal output to PCM/instrument cluster), Gray/Black (ground), and Pink/Orange (12V power supply)
Expected Voltage Range
At Idle
0V to 0.3V
At Higher RPM
0V to 12V
Expected Pattern
Clean square wave switching between 0V and 12V, frequency proportional to output shaft speed
Known-Good Waveform
At 30mph, expect square wave at approximately 120-140Hz with clean transitions between 0V and 11-13V (battery voltage). Pulse width should be consistent with 50% duty cycle. At 60mph, frequency doubles to 240-280Hz. Signal should have sharp rise and fall times (less than 1ms) with no ringing or oscillation at transitions.
Common Failure Patterns
No signal output, voltage stuck at 0V or 12V
Cause: Failed Hall-effect sensor, no power or ground to sensor, broken internal circuit
Erratic or intermittent signal with missing pulses
Cause: Corroded connector pins, damaged sensor wiring, worn tone ring, excessive endplay in output shaft
Weak signal amplitude not reaching full battery voltage or slow rise times
Cause: Low supply voltage to sensor, high resistance in ground circuit, failing sensor output transistor
Diagnostic Tips
Verify 12V supply voltage and good ground at sensor connector with ignition on. This sensor feeds multiple modules including PCM, ABS, and instrument cluster - cross-reference speedometer operation with scan tool VSS data. On 4WD models, ensure sensor is reading transfer case output, not transmission output. Ford 10-speed transmissions (2017+) may use transmission internal speed sensor data instead of traditional VSS.
Related Diagnostic Trouble Codes
P0500P0501P0502P0503
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
Free, no signup. View all waveforms for this vehicle