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:




Wiring Diagram For Crank Signal:






CIRCUIT DESCRIPTION:

Crank signal is a 12.0 volt signal to the ECM during cranking to allow enrichment and cancel diagnostics until engine is running.

TEST DESCRIPTION: The 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 and then go "OFF" when the engine is running.

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