Networked Illumination Operation

The dimmable switches and components are illuminated when the headlamp switch is in the PARK, ON, or AUTO position. The system-wide illumination intensity is determined by the BCM based on based on inputs from the ambient light sensor and the dimmer switch (internal to the headlamp switch).

The BCM sends the dimming level message to the GWM on the HS-CAN1. The GWM divides the signal between the MS-CAN, HS-CAN2, and the HS-CAN3 sending messages to the following modules:

The rear door modules receive their dimming level message from the BCM on a LIN connected to the DDM or PDM. The driver side window control switch also uses a LIN to communicate with the DDM.

MS-CAN 

• PDM
• DDM
• FCIM

HS-CAN2 

• GSM

HS-CAN3 

• IPC
• APIM
• RACM (China only)

If the message is not received, or invalid; a CM DTC is set in the respective module, and the illumination level defaults to full intensity.

The IPC allows a 5 second delay before setting a CM DTC and switching to full intensity. During the 5 second delay, the IPC operates at the illumination intensity last received from the BCM.