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
Spark
The scan tool displays
-64 to +64 degrees. Displays the spark timing being commanded by the PCM on the IC circuit. A negative (-) value indicates degrees BTDC, or spark advance. A positive value indicates degrees After Top Dead Center
(ATDC), or spark retard. Because the
Ignition Control Module (ICM) sets spark advance at a fixed value of
10 degrees BTDC while operating in Bypass mode, the displayed Spark advance only reflects true spark timing when the PCM has commanded IC mode.