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
If it fails: lemon-manuals.org.ua

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Power Mode

The BCM monitors ignition 1 voltage circuit 339, ignition 2 voltage circuit 743 and the Engine Run Flag (ERF). The ERF is a serial data message from the engine controller. The BCM determines the state of the ignition switch for all modules on the serial data link.