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

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Test U: No Communication With the Restraints Control Module

U1:






U1 - U3:






U3 - U4:






U5 - U6:






Normal Operation
The scan tool Communicates with the Restraints Control Module (RCM) monitors through the Data Link Connector (DLC) C251 pin 7, 70 (LB/WH).

Possible Causes
A no communication with the RCM fault can be caused by:
^ Wiring, terminals, or connectors.
^ A faulty Data Link Connector (DLC).
^ RCM is faulted.