System Diagnosis - Crank Signal

Crank Signal Chart:

Crank Signal Circuit:

Circuit Description:
Crank signal is an ignition voltage signal to the ECM during cranking to allow enrichment and cancel diagnostics until engine is operating with 12 volts no longer on the circuit.

Chart 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 and then go OFF" when engine is operating.

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