Fuel Injector
2017 Toyota Camry · 2.5L I4
Sensor Type
inductive
Waveform Type
pulse-width
Location
Four fuel injectors mounted in intake manifold runners, accessed from top of engine
Pins
2-pin connector
Idle Frequency
20 Hz
Timebase
5ms/div
Voltage Scale
20V/div
Trigger
12V, falling edge
Wiring
Power supply (white or pink from EFI relay), Ground signal from ECM (brown, black, gray, or blue for cylinders 1-4)
Expected Voltage Range
At Idle
0V to 14V
At Higher RPM
0V to 14V
Expected Pattern
Battery voltage drops sharply to 0V when injector opens, inductive spike to 50-80V when closing, pulse width 2-3.5ms at idle
Known-Good Waveform
Injector should show clean square wave drop from battery voltage to near 0V with sharp transitions. Pulse width at idle is typically 2.5-3.5ms depending on temperature and fuel trim. Inductive kickback spike when injector closes should reach 50-80V with single sharp peak and quick decay. All four injectors should show identical pulse widths within 0.1ms.
Common Failure Patterns
Slow ramp down when opening or slow ramp up when closing, reduced inductive spike
Cause: High resistance in injector windings, typical resistance should be 13.4-14.2 ohms at 68°F
One injector shows significantly different pulse width than others at idle
Cause: Partially clogged injector or ECM attempting to compensate for vacuum leak at that cylinder
Diagnostic Tips
2AR-FE injectors rarely fail mechanically but can develop restrictions from fuel quality issues. Compare pulse widths between all four cylinders; variance exceeding 0.2ms indicates flow imbalance or vacuum leak. Check connector terminals for corrosion at injector and ECM.
Related Diagnostic Trouble Codes
P0200P0201P0202P0203P0204
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
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