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 spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Spark

The scan tool range is -64° to 64°. Displays the amount of spark advance the PCM is commanding. The PCM computes spark advance using coolant temperature, RPM, engine load, vehicle speed, and requests for timing retard (from the KS system, TCS etc.). The PCM controls the timing and sequencing of the ignition system.