Chart C-1B Crank Signal Diagnosis

Crank Signal Circuit:

Circuit Description
Crank signal is a 12 volt signal to the ECM during cranking to allow enrichment and cancel diagnostics until engine is running and 12 volts is no longer on the circuit.

Crank Signal Diagnostic Chart C-1B:

Test Description
Number(s) below refer to circled number(s) 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.