Ignition Coil Primary
2015 Ford F-150 · 5.0L V8 Coyote
Sensor Type
inductive
Waveform Type
pulse-width
Location
Individual coil-on-plug assemblies mounted directly on each spark plug, valve cover mounted (8 total coils)
Pins
3-pin connector
Idle Frequency
20.8 Hz
Timebase
10ms/div
Voltage Scale
50V/div
Trigger
5V, falling edge
Wiring
Black (ground), Red/Light Blue (12V switched power), Gray/Yellow or other color (PCM trigger signal - varies by cylinder position)
Expected Voltage Range
At Idle
0V to 12V
At Higher RPM
0V to 12V
Expected Pattern
Square wave showing dwell period at ground, then spike to 200-300V during coil collapse, followed by oscillations settling to battery voltage
Known-Good Waveform
Clean dwell period at near 0V for approximately 2-3ms at idle, sharp rise to 200-300V spike during coil shutoff, followed by 3-5 dampened oscillations before settling at battery voltage. Current limiting should show smooth flat dwell with no irregularities.
Common Failure Patterns
Weak spike below 150V or extended ringing oscillations beyond normal dampening
Cause: Failing coil windings, excessive secondary resistance, or weak coil insulation breakdown
Diagnostic Tips
Ford Coyote coils are prone to heat-related failures on cylinders 3, 4, 5, and 6 due to proximity to exhaust. Always check coil boot condition for carbon tracking and verify proper dielectric grease application.
Related Diagnostic Trouble Codes
P0351P0352P0353P0354
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
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