Cranking Signal: Description and Operation

PURPOSE
Sends engine cranking signal to engine control module (ECM) terminal 1C.

REMARKS
Enables ECM to adjust various control outputs for improved engine starts under varying conditions.

OPERATION
The engine cranking signal affects the operation of the following ECM output systems and/or devices:
- Fuel injection quantity
- Fuel injection timing
- Idle air control valve (idle speed)
- A/C relay (A/C cut-off control system)
- Ignition control module (ignition timing control)
- Pressure regulator control solenoid valves (fuel pressure)
- Coolant fan relay (coolant fan control)