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

Information Bus



Data Communication Schematics

DLC Power, Ground and IPM






GMLAN - High Speed, Domestic w/UE1, F55 w/o F55






GMLAN - High Speed, Domestic W/UE1, K59, F55






GMLAN - High Speed, Export w/ TR7/LC3 w/o UE1






GMLAN - High Speed, Export w/ TR7/F55/LC3 w/o UE1






GMLAN - High Speed, Export w/ TT7/ TT8, F55, K59 w/o UE1






GMLAN - Low Speed 1 of 2






GMLAN - Low Speed 2 of 2






GMLAN - High Speed Serial Data Wake Up






Locations: The locations for the Connectors, Grounds, Splices, and Grommets shown within these diagrams can be found via their numbers at Vehicle Locations. Locations