Fuel Injector
2021 Toyota RAV4 · 2.5L I4
Sensor Type
inductive
Waveform Type
pulse-width
Location
Port fuel injectors mounted in intake manifold rail, one per cylinder on intake side
Pins
2-pin connector
Idle Frequency
20 Hz
Timebase
10ms/div
Voltage Scale
20V/div
Trigger
6V, falling edge
Wiring
Brown or White (12V supply from EFI relay), individual color per cylinder for ECM ground control (Pink, Light Green, Yellow, Blue)
Expected Voltage Range
At Idle
0V to 14V
At Higher RPM
0V to 14V
Expected Pattern
Square wave pulse from battery voltage dropping to near 0V when ECM grounds circuit, followed by inductive kickback spike to 50-70V upon shutoff
Known-Good Waveform
At idle, injector should show pulse width of 2-4ms with clean square edges. Voltage drops from 12-14V to approximately 0.5V when activated, then shows sharp positive spike to 50-70V when ECM turns off ground path due to coil collapse. Current ramp should show smooth rise during pulse-on time indicating healthy winding resistance of 13-16 ohms.
Common Failure Patterns
Inductive spike reduced below 40V or absent, rounded pulse edges
Cause: Injector coil winding deterioration or internal short
Erratic pulse width variation or missing pulses at idle
Cause: ECM driver circuit fault or poor connector contact at injector
Diagnostic Tips
RAV4 A25A-FKS uses D-4S dual injection (port and direct) but only under certain conditions; at idle primarily port injection is active. Monitor all four injectors simultaneously to identify pattern inconsistencies. Injector connector C421-C424 corrosion is common in wet climates.
Related Diagnostic Trouble Codes
P0200P0201P0202P0203P0204
Always confirm waveform data with your vehicle's OEM service manual before diagnosing.
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