Operation CHARM: Car repair manuals for everyone.

Oscilloscope Patterns and Waveforms

Inspection Using An Oscilloscope (Reference)




HO2S signal
PCM terminals

- Front HO2S (right bank): 60 (+) - 25 (-)
- Front HO2S (left bank): 87 (+) - 25 (-)
- Rear HO2S (right bank): 35 (+) - 25 (-)
- Rear HO2S (left bank): 61 (+) - 25 (-)

Oscilloscope setting
- 0.5 V/DIV (Y), 500 ms/DIV (X), DC range

Vehicle condition
- Idle after warm up (no load)




HO2S heater control signal
PCM terminals

- Front HO2S heater (right bank): 93 (+) - 25 (-)
- Front HO2S heater (left bank): 94 (+) - 25 (-)
- Rear HO2S heater (right bank): 95 (+) - 25 (-)
- Rear HO2S heater (left bank): 96 (+) - 25 (-)

Oscilloscope setting
- 5 V/DIV (Y), 500 ms/DIV (X), DC range

Vehicle condition
- Idle after warm up (no load)