RAM 1500 Truck 4WD V8-5.9L VIN Z (2002)
connector that is secured by a nut to a ground stud located on the right front fender inner shield in the engine compartment. The washer
pump/motor receives battery current on a washer pump/motor control circuit through a high side driver within the Front Control Module (FCM)
whenever the FCM receives an electronic message from the instrument cluster over the Programmable Communications Interface (PCI) data bus
requesting washer system operation. The instrument cluster monitors a resistor multiplexed hard wired input from the momentary washer switch
contacts within the multi-function switch on the steering column to determine when it should issue the electronic message requesting washer
system operation.
The washer pump/motor unit can be diagnosed using conventional diagnostic tools and methods. However, conventional diagnostic methods may
not prove conclusive in the diagnosis of the instrument cluster, the Front Control Module (FCM), or the electronic message inputs to or outputs
from the instrument cluster and the FCM that control the operation of the washer pump/motor unit. The most reliable, efficient, and accurate
means to diagnose the washer pump/motor unit, the instrument cluster, the FCM, or the electronic message inputs and outputs related to the washer
pump/motor unit operation requires the use of a DRB III scan tool. Refer to the appropriate diagnostic information.
