System Operation
System Diagram
Item | Description |
---|---|
1 | PCM |
2 | Starter relay |
3 | Starter motor |
4 | BCM |
5 | Automatic transmission |
6 | Ignition switch |
Network Message Chart
Module Network Input Messages Powertrain Control Module (PCM)
Broadcast Message | Originating Module | Message Purpose |
---|---|---|
Ignition status | BCM | Provides the PCM with ignition mode. |
Starting System
The BCM controls the ignition modes and, in conjunction with the PCM , the starting system.
During a start event, when the ignition switch is turned to Start (without push button start) or the engine start/stop switch and the brake pedal are pressed (with push-button start), the PCM and BCM receive a request to start the engine. The PCM recognizes the correct inputs from the BCM and TR sensor and provides voltage and ground to energize the starter relay coil and close the starter relay contacts. The starter relay contacts close, providing voltage to the starter solenoid, allowing the starter motor to crank the engine. The PCM disengages the starter motor once an engine RPM threshold is reached, a set crank time is exceeded or the ignition switch is turned to off (without push button start) or the start/stop button is pressed (with push-button start).
If cumulative crank time exceeds 60 seconds within 60 minutes, the starter will be inhibited for 15 minutes to protect starter motor and the PCM sets a DTC . Refer to the Owner's Literature for more information.
Passive Anti-theft System (PATS)
This vehicle is equipped with PATS . PATS 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 a corresponding message in
the message center.
Refer to: Passive Anti-Theft System (PATS) -
System Operation and Component Description (419-01B Passive Anti-Theft
System (PATS) - Vehicles Without: Keyless Entry and Push Button Start,
Description and Operation).
(without Push Button Start) or
Refer to: Passive Anti-Theft System (PATS) - System Operation and
Component Description (419-01C Passive Anti-Theft System (PATS) -
Vehicles With: Keyless Entry and Push Button Start, Description and
Operation).
(with Push Button Start)
Auto-Start-Stop System
The Auto-start-stop system helps reduce fuel consumption by automatically shutting off the vehicle’s engine while the vehicle is at a complete stop and restarting the engine when the brake pedal is released. The system can be disabled through the auto-start-stop control switch on the instrument panel centerstack. The Auto-start-stop system is automatically enabled whenever the ignition is turned on.
The engine automatically restarts when:
The Auto-start-stop system may not turn the engine off under these conditions:
Refer to the Owner's Literature for additional information.
Component Description
Body Control Module (BCM)
Refer to: Module Controlled Functions - Overview (419-10 Multifunction Electronic Modules, Description and Operation).
Ignition Switch (without Push Button Start)
Refer to: Steering Wheel and Column Electrical Components -
Overview (211-05 Steering Wheel and Column Electrical Components,
Description and Operation).
Ignition Switch - Push Button Start (with Push Button Start)
The ignition switch - push button start (engine start/stop button)
is a momentary contact switch that is hardwired to the BCM and the PCM .
The ignition switch - push button start is used to obtain the OFF, ON
or START ignition modes. For more information,
Refer to: Steering
Wheel and Column Electrical Components - Overview (211-05 Steering Wheel
and Column Electrical Components, Description and Operation).
Integrated Keyhead Transmitter (IKT) (without Push Button Start)
Refer to: Passive Anti-Theft System (PATS) - System Operation and
Component Description (419-01B Passive Anti-Theft System (PATS) -
Vehicles Without: Keyless Entry and Push Button Start, Description and
Operation).
Passive Key (with Push Button Start)
Refer to: Passive Anti-Theft System (PATS) - System Operation and
Component Description (419-01C Passive Anti-Theft System (PATS) -
Vehicles With: Keyless Entry and Push Button Start, Description and
Operation).
Passive Anti-Theft Transceiver
Refer to: Passive Anti-Theft System (PATS) - System Operation and
Component Description (419-01B Passive Anti-Theft System (PATS) -
Vehicles Without: Keyless Entry and Push Button Start, Description and
Operation).
Powertrain Control Module (PCM)
The PCM provides power and ground to the starter relay to initiate cranking of the engine.
RTM
Refer to: Handles, Locks, Latches and Entry Systems - System
Operation and Component Description (501-14 Handles, Locks, Latches and
Entry Systems, Description and Operation).