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)

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Sentry Key Immobilizer System(SKIS)

SENTRY KEY IMMOBILIZER SYSTEM(SKIS)
The Sentry Key Immobilizer System (SKIS) is an immobilizer system designed to prevent unauthorized vehicle operation. The system consists of a Sentry Key Immobilizer Module (SKIM), ignition key(s) equipped with a transponder chip and engine controller. When the ignition switch is turned on, the SKIM interrogates the ignition key. If the ignition key is "Valid" the SKIM sends a PCI Bus message to the engine controller indicating the presence of a valid ignition key. Upon receiving a "Valid" key signal the PCM/ECM will allow the engine to continue to operate.

For additional information on the SKIS, refer to the appropriate Powertrain Diagnostic information.