Headlamps - Brazil and Argentina Only
System Diagram
| Item | Description |
|---|---|
| 1 | (without push button start) |
| 2 | (with push button start) |
| 3 | LH low beam |
| 4 | LH high beam |
| 5 | RH low beam |
| 6 | RH high beam |
| 7 | HS-CAN2 |
| 8 | BCM |
| 9 | LH Headlamp |
| 10 | RH Headlamp |
| 11 | SCCM |
| 12 | Headlamp switch |
| 13 | LH steering column multifunction switch |
| 14 | GWM |
| 15 | Ignition switch |
| 16 | HS-CAN1 |
| 17 | Start/Stop switch |
Network Message Chart
BCM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Headlamp flash to pass status | GWM | Indicates to the BCM a request for the high beams or flash-to-pass. |
GWM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Headlamp flash to pass status | SCCM | Indicates to the GWM a request for the high beams or flash-to-pass. |
| Auto high beam request | IPMA | Indicates to the GWM a request for the high beams based on the IPMA camera input. |
Low Beams
The BCM monitors the headlamp switch position by sending voltage signals on multiple circuits to the headlamp switch. There is one circuit for each headlamp switch position. At any given time, one of the signal circuits is switched to ground to indicate the headlamp switch position.
The BCM turns the parking lamps and headlamps on when the ignition is in RUN and the BCM detects a fault from the headlamp switch or wiring. This is normal behavior of the BCM when a fault has been detected with the inputs from the headlamp switch.
When the BCM receives a message requesting the headlamps on, it supplies voltage to the headlamp bulbs within each headlamp assembly.
The BCM also provides Field Effect Transistor (FET) protection of the exterior lamps switched voltage and low beam output circuits. When an excessive current draw is detected, the BCM disables the affected circuit driver. Refer to: Module Controlled Functions - System Operation and Component Description .
Manual Headlamp Leveling
By pressing the headlamp button and releasing it into the popped out position, the switch can be rotated into one of 4 headlamp level positions. This allows headlamp beam height to be adjusted according to vehicle load. Once the beam is adjusted, the button can be pressed again to lock in the headlamp beam height.
High Beams
The SCCM monitors the LH steering column multifunction switch for a high beam request. When the LH steering column multifunction switch is in the HIGH BEAMS position, the SCCM sends a message over the HS-CAN2 to the GWM, then the GWM sends the message to the BCM over the HS-CAN1.
When the low beams are on and the BCM receives a request for high beams, the low beam bulbs remain powered on and the high beam bulbs are also activated. This changes the headlamp beam pattern to illuminate a greater distance.
The BCM also provides Field Effect Transistor (FET) protection of the exterior lamps switched voltage and high beam output circuits. When an excessive current draw is detected, the BCM disables the affected circuit driver. Refer to: Module Controlled Functions - System Operation and Component Description .
Flash-To-Pass
The SCCM monitors the LH steering column multifunction switch for a flash-to-pass request. When the LH steering column multifunction switch is in the FLASH-TO-PASS position, the SCCM sends a message over the HS-CAN2 to the GWM then the GWM sends the message to the BCM over the HS-CAN1.
When the ignition is in RUN and the flash-to-pass is requested, the high beams are activated as long as the LH steering column multifunction switch is held in the flash-to-pass position.
Headlamp Exit Delay
When the ignition is OFF and the LH steering column multifunction switch is placed in the FLASH-TO-PASS position and released, the parking lamps and low beams are illuminated. They remain illuminated until:
- 3 minutes have elapsed with a door open.
- 30 seconds have elapsed after all doors are closed.
- the LH steering column multifunction switch is placed in the flash-to-pass position again.
- the ignition switches to RUN.
Within the 30 second delay and all the doors closed, opening any door results in the 3 minute timer restarting.