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