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)

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Voltage Signal: Testing and Inspection

ECU System:





To test the Battery Signal to the ECU locate pin #3 of connector C50-3 on the ECU, and test for the presence of power. Battery voltage should be read at this pin at all times.

NOTE: To test pins do not remove the connector from the ECU, instead insert a straight pin or needle from the backside of the connector to access the pin.