Description And Operation: Operation

Electric Back Light (EBL):

With the Keyless Ignition Node (KIN) button in the RUN position, the EBL system will automatically turn off after an initial programmed time interval of about 10 minutes.
If the rear window defogger switch is pressed again during the same ignition cycle, the EBL system will automatically turn off after about five minutes.
The EBL system will also turn off if the KIN button is pressed to any position other than RUN or by manually pressing the rear window defogger switch a second time.

When the electric backlight button is pressed, a request signal is sent over the Controller Area Network - Interior High Speed (CAN-IHS) bus to the Body Control Module (BCM) to operate the EBL and the white indicator illuminates within the button. The HVAC module:

Detects the electric backlight enable switch has been pressed.
Broadcasts the message over the CAN-IHS bus.

The BCM:

Receives the "Electric Backlight Enable" request over the CAN-IHS bus.
Applies a Low Side Driver (LSD) in the Power Distribution Center (PDC) to engage the electric backlight relay.

NOTE:

The BCM contains the EBL system control circuitry, including the timer logic. The EBL system turns off automatically after 20 minutes of initial operation. Each following activation cycle of the EBL system will last 20 minutes. After 10 minutes the EBL system turns off automatically if the engine is NOT running (<960 RPM). In this situation the EBL switch in the ICS will remain ON for the duration of the 20 minutes cycle timer.

The EBL switch is diagnosed using a scan tool. There are no relevant DTCs for the switch; use the monitoring function of the scan tool to monitor the BCM inputs.

The EBL switch cannot be adjusted or repaired. Check the wiring and if the rear window defogger switch is inoperative or damaged, the ICS must be replaced.