Oscilloscope Patterns and Waveforms
Inspection Using An Oscilloscope (Reference)
Fuel injection control signal
- PCM terminal
- No.1: 2A (+) <-> 3A (-)
- No.2: 2D (+) <-> 3A (-)
- No.3: 2G (+) <-> 3A (-)
- No.4: 2J (+) <-> 3A (-)
- Oscilloscope setting: 2.0 V/DIV (Y), 20 ms/DIV(X), DC range
- Vehicle condition: Idling after warm-up
IAC control signal
- PCM terminal: 2P (+) <-> 2Q (-)
- Oscilloscope setting: 2.0 V/DIV (Y), 25 ms/DIV (X), DC range
- Vehicle condition: Idling after warm-up (no electrical load)
Purge control signal
- PCM terminal: 3C (+) <-> 4A (-)
- Oscilloscope setting: 2.0 V/DIV (Y), 10 ms/DIV (X), DC range
- Vehicle condition:
- ECT: above 80 °C {176 °F}
- D range and 7.5 km/h {5 mph} or below
IGT control signal
- PCM terminal:
- 3F (+) <-> 4A (-)
- 3I (+) <-> 4A (-)
- Oscilloscope setting: 1.0 V/DIV (Y), 50 ms/DIV (X), DC range
- Vehicle condition: Idling after warm-up
Generator field coil signal
- PCM terminal: 3M (+) <-> 4A (-)
- Oscilloscope setting: 0.5 V/DIV (Y), 2.5 ms/DIV (X), DC range
- Vehicle condition: Idling after warm-up (no electrical load)
Engine speed signal
- PCM terminal: 3O (+) <-> 4A (-)
- Oscilloscope setting: 2.0 V/DIV (Y), 20 ms/DIV (X), DC range
- Vehicle condition: Idling
Vehicle speed signal
- PCM terminal: 3T (+) <-> 4A (-)
- Oscilloscope setting: 1.0 V/DIV (Y), 10 ms/DIV (X), DC range
- Vehicle condition: Driving 50 km/h [31 mph]
SGC signal
- PCM terminal: 3V (+) <-> 4A (-)
- Oscilloscope setting: 2.0 V/DIV (Y), 20 ms/DIV (X), DC range
- Vehicle condition: Idling
NE signal
- PCM terminal: 3Y (+) <-> 4A (-)
- Oscilloscope setting: 1.0 V/DIV (Y), 5.0 ms/DIV (X), DC range
- Vehicle condition: Idling
Oil control valve (OCV) signal
- PCM terminal: 4D (+) <-> 4A (-)
- Oscilloscope setting: 2.0 V/DIV (Y), 0.5 ms/DIV (X), DC range
- Vehicle condition: Idling after warm-up (no electrical load)
HO2S (front) signal
- PCM terminal: 4W (+) <-> 4A (-)
- Oscilloscope setting: 0.2 V/DIV (Y), 2.0 ms/DIV (X), DC range
- Vehicle condition: Idling after warm-up