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

Test K

PINPOINT TEST K: NO INTERNATIONAL STANDARDS ORGANIZATION (ISO) 9141 NETWORK COMMUNICATION


Test K1-K4:






Test K5-K8:






Normal Operation
The restraint control module (RCM) communicates with the diagnostic tool through the international standards organization (ISO) 9141 communications network. Circuit 4-EE1(GY/RD) receives and transmits data from the data link connector (DLC) to the RCM through in-line C214. The ability to communicate on the ISO 9141 network will be disabled if the circuit is open, shorted to ground or shorted to voltage.

Possible Causes
- circuit 4-EE1 (GY/RD) open or shorted
- RCM C310a
- DLC C251
- RCM
- ABS module