Operation CHARM: Car repair manuals for everyone.
Hosted by mcallihan.com

Oscilloscope Patterns and Waveforms

Inspection Using An Oscilloscope (Reference)




HO2S (front) signal
PCM terminals

1AB(+) - 2H(-)

Oscilloscope setting
- 0.1 V/DIV (Y), 400 ms/DIV (X), DC range

Vehicle condition
- Idle after warm up (engine speed approx. 650 rpm, no load, P/S off, A/C off)




HO2S (front) heater control signal
PCM terminals

4A (+) - 1C(-)

Oscilloscope setting
- 4 V/DIV (Y), 200 ms/DIV (X), DC range

Vehicle condition
- Idle after warm up (engine speed approx. 650 rpm, no load, P/S off, A/C off)