B1970
CIRCUIT DESCRIPTIONWith the ignition switch in the ON position, the Body Control Module (BCM) supplies battery positive voltage to the HEADLAMPS relay coil, and the PARK LAMPS relay coil. The BCM monitors the voltage on the headlamp relay coil supply voltage circuit every 300 ms.
CONDITIONS FOR RUNNING THE DTC
^ The Ignition switch is in the ON position.
^ The exterior lamps are commanded on for at least 300 ms.
CONDITIONS FOR SETTING THE DTC
The headlamp relay coil supply voltage circuit is low for at least 600 ms.
ACTION TAKEN WHEN THE DTC SETS
The BCM turns OFF the exterior lamps output, until the condition for setting the DTC is no longer present.
CONDITIONS FOR CLEARING THE DTC
The DTC will clear when the voltage on the headlamp relay coil supply voltage circuit is no longer low for at least 600 ms.
TEST
