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

Data Link Connector: Description and Operation

There are two data lines that can be accessed with a scan tool. The 800 circuit data line (CLASS 1) is the Powertrain Control Module (PCM) Data Line. It allows the PCM, Electronic Brake Control Module (EBCM) (if equipped), and the Diagnostic Energy Reserve Module (DERM) to communicate by transmitting data through CKT 800. The other data line (CLASS 2) is CKT 1807 which also allows the PCM to communicate.

A scan tool can be connected to the Data Link Connector (DLC); this allows the scan tool to communicate with the PCM Data Line. System operations can then be monitored for diagnostic purposes.