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

Oscilloscope Patterns and Waveforms

Manufacturer Specific Pattern

SGC signal




- PCM terminal: 85 (+) <-> 86(-)
- Oscilloscope setting: 0.5 V/DIV (Y), 10 ms/DIV (X), AC range
- Vehicle condition: Idle after warm up