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

Relay Test (F6)

This test allows the user to turn the relay on and off using the up arrow and down arrow keys on the TECH-1. The battery voltage supplied to the Electronic Brake Control Module (EBCM) through the relay contacts is displayed on the screen during the test. When the relay is commanded on, the voltage should be equal to the battery voltage. When the relay is off, the voltage should drop below 2 volts.

NOTE: Voltage will not drop to zero when the relay contacts are open due to capacitors in the EBCM. If voltage drops below 2 volts, the relay is operating properly.