Starting System

This vehicle is equipped with a PATS that disables the engine from starting if an unprogrammed PATS key is used or an invalid PCM ID is received. The PATS is controlled by the BCM. If there is a PATS concern that disables the engine, the IPC displays the corresponding message in the message center. Refer to: Perimeter Anti-Theft Alarm - System Operation and Component Description .

Under normal operation, when the ignition is turned to START, the PCM receives the following inputs:

• Request to crank engine message from the BCM
• PATS enable message from the BCM
• Voltage from the run/start relay
• Correct transmission park or neutral input from the automatic transmission

When the PCM receives the correct inputs, voltage and ground is supplied to the starter relay coil. When the starter relay coil is energized, it provides voltage to the starter solenoid, allowing the starter motor to crank the engine.

The PCM disengages the starter once an engine Revolutions Per Minute (RPM) threshold is reached, a set crank time is exceeded or the ignition is turned OFF.