Headlamp Windshield Washer Pump - Operation

HEADLAMP

Headlamp washer pump/motor unit operation is completely controlled by the Body Control Module (BCM) (also known as the Signal Acquisition and Actuation Module/SAM) logic circuits based upon electronic wash command message inputs received from the Steering Control Module (SCM) (also known as the steering column module/MRM) based upon the multi-function switch position, and upon hard wired inputs from the headlamp switch (also known as the rotary light switch module) on the instrument panel. The BCM will only allow the headlamp washers to operate when the ignition switch is in the ON position and the headlamps are turned ON. The BCM uses high side drivers to energize or de-energize the headlamp washer system relay which, in turn, controls the operation of the headlamp washer pump/motor unit.

The hard wired circuits and components of the headlamp washer pump/motor unit may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. However, conventional diagnostic methods will not prove conclusive in the diagnosis of the headlamp washer pump/motor or the electronic controls or communication between other modules and devices that provide some features of the headlamp washer system. The most reliable, efficient, and accurate means to diagnose the headlamp washer pump/motor unit or the electronic controls and communication related to headlamp washer pump/motor unit operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.