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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Circuit Operation

A Scan Tool can be connected to the Data Link Connector (DLC) which allows the Scan Tool to communicate with either the Powertrain Control Module (PCM) or the Diagnostic Energy Reserve Module (DERM). System operations can then be monitored for diagnostic purposes.

There are two data lines access with a Scan Tool. Circuit 800 (TAN) UART data line allows the DERM to communicate with the Scan Tool. Circuit 1807 (PPL) CLASS-2 data line allows the PCM to communicate with a Scan Tool.