Dodge dakota 2002 Service Manual page 536

DR
WASHER FLUID INDICATOR (Continued)
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the indicator will
always be off when the ignition switch is in any posi-
tion except On or Start. The indicator only illumi-
nates when it is switched to ground by the
instrument cluster circuitry. The instrument cluster
will turn on the washer fluid indicator for the follow-
ing reasons:
• Washer Fluid Indicator Lamp-On Message -
Each time the cluster receives a washer fluid indica-
tor lamp-on message from the FCM indicating that a
low washer condition has been detected for sixty con-
secutive seconds, the washer fluid indicator is illumi-
nated and a single chime tone is sounded. The
indicator remains illuminated until the cluster
receives a washer fluid indicator lamp-off message
for sixty consecutive seconds from the FCM or until
the ignition switch is turned to the Off position,
whichever occurs first. The chime tone feature will
only repeat during the same ignition cycle if the
washer fluid indicator is cycled off and then on again
by the appropriate washer fluid lamp messages from
the FCM.
• Actuator Test - Each time the cluster is put
through the actuator test, the washer fluid indicator
will be turned on, then off again during the VFD por-
tion of the test to confirm the functionality of the
VFD and the cluster control circuitry.
The FCM continually monitors the washer fluid
level switch in the washer reservoir to determine the
level of the washer fluid. The FCM then sends the
proper washer fluid indicator lamp-on and lamp-off
messages to the instrument cluster. For further diag-
nosis of the washer fluid indicator or the instrument
cluster circuitry that controls the indicator, (Refer to
8 - ELECTRICAL/INSTRUMENT CLUSTER - DIAG-
NOSIS AND TESTING). For proper diagnosis of the
washer fluid level switch, the FCM, the PCI data
bus, or the electronic message inputs to the instru-
ment cluster that control the washer fluid indicator,
a DRBIII scan tool is required. Refer to the appro-
priate diagnostic information.
INSTRUMENT CLUSTER
WATER-IN-FUEL INDICATOR
DESCRIPTION
A water-in-fuel indicator is only found in the
instrument clusters for vehicles equipped with an
optional diesel engine. The water-in-fuel indicator is
located near the lower edge of the instrument cluster,
between the tachometer and the speedometer. The
water-in-fuel indicator consists of stencil-like cutout
of the International Control and Display Symbol icon
for "Water In Fuel" in the opaque layer of the instru-
ment cluster overlay. The dark outer layer of the
overlay prevents the indicator from being clearly vis-
ible when it is not illuminated. A red Light Emitting
Diode (LED) behind the cutout in the opaque layer of
the overlay causes the icon to appear in red through
the translucent outer layer of the overlay when the
indicator is illuminated from behind by the LED,
which is soldered onto the instrument cluster elec-
tronic circuit board. The water-in-fuel indicator is
serviced as a unit with the instrument cluster.
OPERATION
The water-in-fuel indicator gives an indication to
the vehicle operator when there is excessive water in
the fuel system. This indicator is controlled by a
transistor on the instrument cluster circuit board
based upon the cluster programming and electronic
messages received by the cluster from the Engine
Control Module (ECM) over the Programmable Com-
munications Interface (PCI) data bus. The water-in-
fuel indicator Light
completely controlled by the instrument cluster logic
circuit, and that logic will only allow this indicator to
operate when the instrument cluster receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the LED will
always be off when the ignition switch is in any posi-
tion except On or Start. The LED only illuminates
when it is provided a path to ground by the instru-
ment cluster transistor. The instrument cluster will
turn on the water-in-fuel indicator for the following
reasons:
8J - 43
Emitting Diode (LED) is