Collision Avoidance: Notes
Overview
The forward collision warning system alerts the driver of a collision risk with a red warning LED indicator bar located above the instrument panel (which is part of the HUD module) and an audible warning chime from the IPC.
System Operation
System Diagram
Network Message Chart
Network Message Chart - ACM
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Audio mute | C-CM | Data used to command audio mute during possible collision event so that the warning chime can be heard. |
Network Message Chart - C-CM
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| HUD data | HUD module | Used for HUD active, available and fault status. |
Network Message Chart - HUD Module
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Forward collision warning HUD flash command | C-CM | Flashes the HUD LED array when commanded. |
| Ignition status | BCM | Used for ignition switch position input. |
Network Message Chart - ABS Module
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Adaptive cruise control_brake deceleration request | C-CM | Request for braking when a slower vehicle ahead is detected by the C-CM. |
Network Message Chart - IPC
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Forward collision warning request | C-CM | Data used to command chime during a possible collision event. |
| Adaptive cruise control warning display | C-CM | Data used to command chime and messages during a possible collision event. |
Collision Avoidance Operation
The forward collision warning system works in conjunction with the adaptive cruise control system. During a possible collision event, the C-CM commands:
- the HUD to flash red warning LEDs.
- the IPC to activate a chime and commands.
- ACM to mute audio volume.
The forward collision warning system is activated when the vehicle is moving forward at a speed greater than 8 kmh (5 mph). The C-CM determines the distance and relative speed of the vehicle that is in the path of travel, utilizing a radar sensor (integral to the C-CM) to detect other vehicles that are moving in the same direction. If the C-CM determines that a collision is possible, the C-CM commands the HUD module LEDs to flash and the IPC to chime.
The forward collision warning system and audible warning chime can be enabled and disabled through the message center display in the IPC. The system reverts to on each ignition cycle. The HUD module and/or chime activates briefly to confirm the last setting.
For vehicles with a base IPC, the sensitivity of detection is changed in the message center from a high sensitivity (<----->) to a low sensitivity (<->). For vehicles with an optional IPC, there are three levels of sensitivity detection (LONG, NORMAL and SHORT) that are changed in the message center display.
If a MyKey® restricted key is in use, the MyKey® turns on the forward collision warning and will not allow the MyKey® user to disable the audio or visual forward collision warning system. However, the MyKey® user is able to adjust the forward collision warning sensitivity.
When a system fault is detected with the forward collision warning system the message COLLISION WARN NOT AVAILABLE, COLLISION WARN NOT AVAILABLE SENSOR BLOCKED, or COLLISION WARNING MALFUNCTION is displayed in the IPC message center.