Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the logical successor to CHARM, I recommend you try it!

Link: lemon-manuals.la

Except California Emission Regulation Applicable ATX Model

Inspection Using An Oscilloscope (Reference) (Except for California emission regulation applicable ATX model)

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. 700 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. 700 rpm, no load, P/S off, A/C off)