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 key is used or an invalid PCM ID is received. PATS is controlled by the Instrument Panel Cluster (IPC). If there is a PATS concern that caused the engine to be disabled, the anti-theft light flashes rapidly in the IPC. Refer to Anti-Theft - Passive Anti-Theft System (PATS) Testing and Inspection to diagnose a PATS concern.

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

- Correctly coded ignition key from the IPC
- Clutch pedal applied from the Clutch Pedal Position (CPP) switch (vehicles equipped with manual transaxle)
- Transaxle in PARK or NEUTRAL from the Transmission Range (TR) sensor (vehicles equipped with automatic transaxle)
- 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 generates a key verification message. It sends this message to the PATS transceiver. The transceiver reads the key and sends a key verification message back to the IPC. If the message received does not match the key verified in the IPC memory, the engine will not crank and start. Once the IPC determines the correct programmed key was used to START the vehicle, the IPC 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. If the response from the PCM does not match the response in the IPC memory, PATS is not enabled and the engine does not crank. If both the key verification and PCM ID pass, PATS 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 Anti-Theft - Passive Anti-Theft System (PATS) Anti-Theft - Passive Anti-Theft System (PATS).

Vehicles equipped with an automatic transaxle have a TR sensor. The TR sensor prevents operation of the starter unless the transaxle is in NEUTRAL or PARK.

Vehicles equipped a manual transaxle have a CPP switch. The CPP switch prevents operation of the starter unless the clutch pedal is fully pressed.