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HomeWaveforms2021 Toyota CamryFuel Injector

Fuel Injector

2021 Toyota Camry · 2.5L I4 Hybrid

65V-7.5V-80V5ms/div | 20V/divpulse-width
Sensor Type
inductive
Waveform Type
pulse-width
Location
Port fuel injectors in intake manifold runner, side of cylinder head
Pins
2-pin connector
Idle Frequency
16.7 Hz
Timebase
5ms/div
Voltage Scale
20V/div
Trigger
6V, falling edge

Wiring

Red or Pink (12V power from EFI relay), individual ECM control wires vary by cylinder position

Expected Voltage Range

At Idle
-80V to 65V
At Higher RPM
-90V to 70V

Expected Pattern

12V supply drops to ground during injection, inductive kick to 60-70V at close, negative spike -70 to -90V at opening

Known-Good Waveform

Injector waveform shows 12V baseline dropping sharply to near 0V when ECM grounds the circuit. Opening shows negative inductive spike of -70 to -90V for approximately 0.2ms. Pulse width at idle is typically 2.5-3.5ms. At end of injection, positive inductive kick to 60-70V as magnetic field collapses, then clean return to 12V baseline with minimal oscillation.

Common Failure Patterns

Slow voltage drop at opening, reduced or absent negative spike, rounded transitions
Cause: High resistance in injector coil windings or connector corrosion, failing injector solenoid
Related DTCs: P0201, P0202, P0203, P0204
Excessive oscillation or ringing after closing spike, irregular pulse width
Cause: Shorted turns in injector coil or intermittent internal connection
Related DTCs: P0201, P0202, P0203, P0204, P0300
Extended pulse width above 8ms with rich condition codes
Cause: Weak fuel pressure from aging hybrid fuel pump, clogged fuel filter, or faulty pressure regulator
Related DTCs: P0171, P0172, P0087

Diagnostic Tips

Hybrid system uses electric fuel pump that cycles on/off with engine operation; verify fuel pressure before condemning injector pulse width. Compare all four injectors simultaneously to identify outliers. Port injection system prone to carbon buildup requiring periodic cleaning.

Related Diagnostic Trouble Codes

P0200P0201P0202P0203P0204
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.

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