Network Message Chart - Push Button Ignition Switch
GWM Module Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Ignition status | BCM | This message informs the GWM of the current ignition status; off, run, start, unknown or invalid. |
PCM Module Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Ignition status | BCM | This message informs the PCM of the current ignition status; off, run, start, unknown or invalid. |
Push Button Ignition Switch
The push button ignition switch is used to control the ignition mode.
There are 2 circuits the BCM monitors from the ignition switch to change the ignition mode. One circuit is monitored for voltage and the other for a ground signal. When the START/STOP button is pressed, one circuit routes battery voltage to the BCM while a voltage signal from the BCM on the second circuit is routed to ground, indicating a request to change the ignition state. Changing the ignition state from the OFF mode works in conjunction with the PATS. The BCM must recognize a valid programmed key before it changes the ignition mode out of OFF. Refer to: Passive Anti-Theft System (PATS) - System Operation and Component Description .
Refer to the following table for information about achieving the various ignition states.
| Ignition Entry Condition | Desired Ignition Mode | Action To Take |
|---|---|---|
| Off | ON (engine off) | Press the START/STOP button without applying the brake pedal. |
| Off or on | START | Apply and the brake pedal (automatic transmission) or fully apply the clutch (manual transmission) and then press the START/STOP button. |
| On (engine off) | OFF | Press the START/STOP button. |
| On (engine running) | OFF | Press and hold the START/STOP button. |
Ignition Mode LED Indicator
The ignition mode LED indicates the ignition mode of the vehicle. The BCM controls the voltage to the ignition mode LED indicator. Refer to the following table.
| Ignition Mode | Ignition Mode LED Indicator |
|---|---|
| Off | Off |
| On (engine off) | Flashing |
| On (engine running) | On |
OFF
The BCM controls the relays providing voltage to the vehicle electrical systems. When the ignition is in the ON mode, a single press and release of the START/STOP button changes the ignition to the OFF mode. No programmed key is required to change the ignition to the OFF mode when the vehicle is running.
If the vehicle is in motion, a momentary press of the START/STOP button does not shut the vehicle off. If the vehicle is moving at a speed greater than 15 km/h (9 mph), the START/STOP button must be pressed and held for longer than one second (or pressed 3 times within 2 seconds) to turn the ignition off.
When the BCM changes the ignition state to OFF, it communicates the ignition mode to the other modules by sending an ignition status message over the CAN.
ON
The BCM must recognize a programmed key before it changes the ignition mode out of OFF. When the START/STOP button is pressed when the ignition is off, the BCM checks the vehicle for a valid programmed key as part of the PATS function. If no valid programmed key is detected, the ignition remains off. Refer to: Passive Anti-Theft System (PATS) - System Operation and Component Description .
When the ignition is in the ON mode, the BCM activates the run/start relay to provide voltage to the vehicle electrical systems and communicates the ignition mode to the other modules by sending an ignition status message over the CAN.
When the vehicle enters ON mode, multiple indicators in the IPC prove out and the IPC displays the gear selection and the vehicle mileage.
START
If the brake pedal is applied when the START/STOP button is pressed with the ignition in the off mode, the vehicle temporarily goes into the START mode so long as a valid programmed key is detected within the vehicle.
In addition to activating the run/start relay, the BCM communicates the ignition mode to the other modules by sending an ignition status message over the CAN.
Once the ignition has entered START mode, the ignition mode indicator in the ignition switch illuminates.
The engine can be started from any ignition mode.
System Diagram - Steering Column Lock
Network Message Chart - Steering Column Lock
BCM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Engine RPM data | PCM | Provides the BCM with the engine speed to indicate if it is running or not. |
| Wheel rotation count | ABS module | Provides the BCM with the vehicle speed to indicate if it is moving or stationary. |
Steering Column Lock
The steering column lock is used to deter vehicle theft by electronically locking the steering column. This prevents the steering wheel from being rotated to turn the front wheels.
The steering column unlocks when:
- the passive entry feature is used to open the driver door.
- the driver door is opened after unlocking the vehicle with a RKE transmitter.
- the START/STOP button is pressed and a valid programmed passive key is detected.
- the remote start feature is activated.
The steering column locks after:
- the ignition is turned off and 45 seconds have elapsed since the delayed accessory feature has turned off.
- 45 seconds have elapsed since the remote feature turns off the vehicle.
The BCM controls the voltage provided to the steering column lock module using a relay (located in the BJB) and communicates with it over a LIN. The BCM monitors input from various systems to determine when to send a command to lock or unlock the steering column. The steering column lock module locks and unlocks the steering column as directed by commands received from the BCM.
If the BCM detects a fault from the steering column lock module or the LIN, the BCM prevents the vehicle from starting.
The BCM does not provide power to the steering column lock module when the vehicle is moving or the engine is running.
Steering Column Lock Messages
The message center displays a message when the BCM detects a fault from the steering column lock module.
The Steering Malfunction message displays when a fault with the electronic steering column lock system is present and must be diagnosed.
The Turn the wheel while starting message displays when the steering column lock module is unable to unlock the steering column because of a high amount of torque against the lock (such as when the wheels are against a curb when the vehicle is shut off). The torque against the steering column lock must be relieved for the steering column to unlock.
Turn the vehicle off, rotate and hold the steering wheel in one direction while turning the vehicle on. If the message displays again, turn the vehicle off, rotate and hold the steering wheel in the other direction while turning the vehicle on.