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

Module Circuit Function Icons



Module Circuit Function Icons






I/O Pull-Down Resistors (-)






I/O Pull-Up Resistors (+)






I/O High-Side Drive Switch (+)






I/O Low-Side Drive Switch (+)






I/O Bidirectional Switch (+/-)






Pulse-Width Modulation Symbol






Battery Voltage






Ignition Voltage






Voltage Reference






A/C Voltage






Low Reference






Ground






Serial Data






Antenna Signal - In






Antenna Signal - Out






Brake Apply