Pinpoint Test A: The Forward Collision Warning System Is Inoperative

Forward Collision Warning

Pinpoint Tests

Pinpoint Test A: The Forward Collision Warning System Is Inoperative

Refer to Wiring Diagram Set 136, Vehicle Emergency Messaging System for schematic and connector information. [1][2]Diagrams By Number

Normal Operation

The forward collision warning system is enabled when the ignition switch is in the RUN position. The Body Control Module (BCM) sends an ignition state message over the High Speed Controller Area Network (HS-CAN) to the Head Up Display (HUD) module. The LEDs that are internal to the HUD (Head Up Display) module illuminate for a few seconds to indicate the system is operational.

The radar sensor unit, which is integral to the Cruise-Control Module (C-CM), sends out a radar signal to the vehicle in the path of travel and receives the radar signal back to determine the distance and relative speed of that vehicle. The C-CM (Cruise-Control Module) sends a message via the HS-CAN (High Speed Controller Area Network) to the HUD (Head Up Display) module if the vehicle in the path of travel enters the preset gap for a collision warning. The HUD (Head Up Display) module receives a message from the C-CM (Cruise-Control Module) to flash the LEDs. The C-CM (Cruise-Control Module) also sends a message to the Instrument Panel Cluster (IPC) to activate a chime from the IPC (Instrument Panel Cluster) and gateways a message over the Infotainment Controller Area Network (ICAN) to mute the Audio Control Module (ACM) volume. The system can be disabled through the IPC (Instrument Panel Cluster) message center.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors

- C-CM (Cruise-Control Module)

- HUD (Head Up Display) module

- IPC (Instrument Panel Cluster)