Engine Start-Up

THIS IS AN OPEN LOOP MODE.
When the starter motor is engaged, the Powertrain Control Module (PCM) receives input from:
^ Battery voltage

^ Crankshaft position (CKP) sensor

^ Engine coolant temperature (ECT) sensor

^ Intake air temperature (IAT) sensor

^ Throttle position sensor (TPS)

^ Camshaft position (CMP) sensor

^ Starter relay

Based on these inputs the PCM will:
^ Monitor crankshaft and camshaft position sensor. If signals are not received within 1 second, the PCM will shut down the Automatic Shutdown (ASD) and fuel pump relays.

^ Supply the injectors with a ground path, firing all injectors until the PCM determines crankshaft position.

^ Fire injectors in sequence, once PCM has determined crankshaft position.

^ Compare RPM Manifold Absolute Pressure (MAP) sensor reading to idle speed MAP sensor reading. If the PCM does not detect a minimum difference it will set a Diagnostic Trouble Code.

^ Determine proper ignition timing.