Principles Of Operation - Without Intelligent Access (IA)

Starting System

Principles of Operation - Without Intelligent Access (IA)

NOTE: This vehicle is equipped with Passive Anti-Theft System (PATS) that disables the engine if an unprogrammed PATS (Passive Anti-Theft System) key is used or an invalid PCM ID is received. PATS (Passive Anti-Theft System) is controlled by the Instrument Panel Cluster (IPC). If there is a PATS (Passive Anti-Theft System) concern that caused the engine to be disabled, the anti-theft light flashes rapidly in the IPC (Instrument Panel Cluster). Refer to Antitheft and Alarm Systems to diagnose a PATS (Passive Anti-Theft System) concern.

The starting system is electronically controlled by the PCM. The PCM receives the following inputs:

- Correctly coded ignition key from the IPC (Instrument Panel Cluster)

- Clutch pedal applied from the Clutch Pedal Position (CPP) switch (vehicles equipped with manual transmission)

- Transmission in PARK or NEUTRAL from the Transmission Range (TR) sensor (vehicles equipped with automatic transmission)

- Request to start the engine, ignition switch in the START position

Under normal operation when the ignition is turned to the START position the IPC (Instrument Panel Cluster) generates a key verification message. It sends this message to the PATS (Passive Anti-Theft System) transceiver. The transceiver reads the key and sends a key verification message back to the IPC (Instrument Panel Cluster). If the message received does not match the key verified in the IPC (Instrument Panel Cluster) memory, the engine will not crank and start. Once the IPC (Instrument Panel Cluster) determines the correct programmed key was used to START the vehicle, the IPC (Instrument Panel Cluster) sends the PCM a request to crank and start the engine. When the PCM receives the message, it generates a response and sends it back to the IPC (Instrument Panel Cluster). If the response from the PCM does not match the response in the IPC (Instrument Panel Cluster) memory, PATS (Passive Anti-Theft System) is not enabled and the engine does not crank. If both the key verification and PCM ID pass, PATS (Passive Anti-Theft System) is enabled. The PCM recognizes the correct electronically coded passive key and provides voltage and ground to the starter relay coil. The starter relay coil is energized causing the relay contacts to close providing voltage to the starter solenoid, allowing the starter motor to crank and start the engine. The PCM disengages the starter once an engine rpm threshold is reached, a set crank time is exceeded or the ignition is turned OFF. For additional information, refer to Antitheft and Alarm Systems.

Vehicles equipped with an automatic transmission have a TR (Transmission Range) sensor. The TR (Transmission Range) sensor prevents operation of the starter unless the transmission is in NEUTRAL or PARK.

Vehicles equipped a manual transmission have a CPP (Clutch Pedal Position) switch. The CPP (Clutch Pedal Position) switch prevents operation of the starter unless the clutch pedal is fully pressed.