Exterior Lighting - System Operation and Component Description: DRL
System Diagram
Network Message Chart
BCM Network Input Messages
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Gear position | PCM | Indicates the GSM request to the BCM. When the GSM has selected any position other than park, the BCM activates the DRL. |
DRL
For halogen headlamps, the DRL system utilizes the existing circuitry and components from the headlamp low beam system. The DRL system operates the low beam headlamps at a reduced intensity.
For LED headlamps, the DRL system operates the DRL/parking surround Light Emitting Diodes (LEDs) at full intensity using a PWM voltage circuit.
The BCM monitors the ignition status, the headlamp switch and autolamp status.
When the ignition is in ON, the BCM supplies voltage to each headlamp assembly.
The BCM monitors the ignition status, the headlamp switch and autolamp status.
There are two types of DRL, conventional (where it is required) and configurable.
When equipped with conventional DRL, the DRL are active in any headlamp switch position except the HEADLAMPS position.
The conventional DRL are activated when all of the following conditions are met:
- The ignition is ON.
- The headlamps switch is in OFF, PARKLAMPS or AUTOLAMPS position and the headlamps have not been turned on by the autolamp system.
- The transmission is not in PARK.
When equipped with configurable DRL, the DRL may be enabled through the IPC message center. When enabled, the DRL are active only in the AUTOLAMPS headlamp position. When autolamps request the headlamps on, the DRL are deactivated.
The configurable DRL are activated when all of the following conditions are met:
- The ignition is ON.
- The headlamps switch is in AUTOLAMPS position and the headlamps have not been turned on by the autolamp system.
- The transmission is not in PARK.
When the transmission is in not in PARK, the PCM sends a message over the HS-CAN1 to the BCM indicating the transmission is not in PARK.
For halogen headlamps, the BCM also provides Field Effect Transistor (FET) protection of the exterior lamps switched voltage and DRL output circuits. When an excessive current draw is detected, the BCM disables the affected circuit driver.