High Beams (Except Envoy, Diamond Edition W/HID and ZR2)

Battery positive voltage to the headlamp switch is supplied by the HDLP SW fuse in the IP fuse block. When the headlamp switch is in the HDLP position, the headlamp power relay coil is energized. A voltage signal is also sent to the Body Control Module (BCM) signaling that the headlamp switch is activated. When the headlamp switch is in the AUTO or PARK position and the ambient light sensor detects darkness, the BCM produces a voltage signal that will also energize the headlamp power relay. The headlamp power relay coil is grounded at G102. When the headlamp power relay is energized, the relay supplies battery voltage to the LT HDLP and RT HDLP fuses. The RH high beam headlamp receives current directly from the RT HDLP fuse. When the headlamp switch is in the HDLP position, the BCM removes the ground path to the headlamp grounding and DRL relay coils. This allows current to flow to the LH high beam headlamp through the normally closed contacts of the DRL relay. Both high beam headlamps are grounded by the multifunction headlamp dimmer switch in the high beam position through the normally closed contacts in the headlamp grounding relay to G200. A ground signal is also sent to the BCM in order to confirm high beam operation.

"For a description of the RPO Code(s) shown in this article or any of the images therein, refer to the RPO Code List found at Vehicle/Application ID". RPO Codes