Fuel Injector
2018 Jeep Wrangler · 3.6L V6
Sensor Type
inductive
Waveform Type
pulse-width
Location
Port fuel injectors mounted in intake manifold rail, one per cylinder on each bank
Pins
2-pin connector
Idle Frequency
16.67 Hz
Timebase
10ms/div
Voltage Scale
20V/div
Trigger
6V, falling edge
Wiring
Dark Green/Orange (12V power from ASD relay) and individual driver wires per cylinder (PCM ground switching)
Expected Voltage Range
At Idle
0V to 65V
At Higher RPM
0V to 70V
Expected Pattern
12V hold voltage during off-time, drops to 0V when PCM grounds injector, inductive spike to 50-65V at turn-off with current decay lasting 0.2-0.5ms
Known-Good Waveform
At idle, pulse width should be 2.5-4.5ms with injector firing once per engine cycle (sequential). Battery voltage should be present during off-time, sharp pull-down to near 0V when energized, and clean inductive spike to 50-65V at turn-off. Current ramp during on-time should be smooth without hash or noise.
Common Failure Patterns
Inductive spike exceeds 80V or shows multiple oscillations
Cause: High resistance in injector coil or corroded connector pins
Voltage does not pull to ground, stays near 12V
Cause: Open injector coil winding or failed PCM driver circuit
Diagnostic Tips
The 3.6L uses sequential port injection; verify injector resistance of 11-13 ohms at room temperature. Common issue is contaminated fuel causing internal varnish deposits affecting spray pattern without setting injector-specific codes.
Related Diagnostic Trouble Codes
P0200P0201P0202P0203P0204
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
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