Operation CHARM: Car repair manuals for everyone.

ZR2

On a vehicle with the ZR2 option, the daytime running lamps utilize the low beam headlamps equipped with a long life bulb in a parallel circuit Voltage is supplied by the headlamp power relay as in normal low beam operation to each low beam headlamp bulb however the ground is controlled by the DRL relay. When the BCM requests for DRL operation, it will apply battery positive voltage energizing the headlamp power relay coil and ground activating the DRL relay coil. The DRL relay bypasses the multifunction headlamp dimmer switch completing the headlamp low beam ground circuit to G102. The parameters required to operate the system are the same as a vehicle without the ZR2 option.

"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