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

Sentry Key Remote Entry Module System (SKREEM) Overview

The sentry key remote entry module system (SKREEM) is designed to prevent unauthorized vehicle operation. The system consists of a sentry key remote entry module (SKREEM), ignition key(s) equipped with a transponder chip and the ECM. When the ignition switch is turned on, the SKREEM interrogates the ignition key. If the ignition key is Valid or Invalid, the SKREEM sends a message to the ECM indicating ignition key status. Upon receiving this message the ECM will terminate engine operation or allow the engine to continue to operate.