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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Cranking Signal: Testing and Inspection

Chart C-1B - Crank Signal:




Wiring Diagram for Chart C-1B - Crank Signal:





CHART C-1B - CRANK SIGNAL

Circuit Description:


The ECM uses crank signal information to provide cranking enrichment when the ECM is in a back-up mode.


Test Description: Numbers below refer to circled numbers on the diagnostic chart.

1. Checks for normal (cranking) voltage to terminal "C9" of ECM. Test light should be "ON" during cranking.


2. Checks to determine if source of blown fuse was a faulty ECM.