7 ELECTRONIC CONTROL SYSTEMS DIAGNOSTICS 551
WIF Circuit Operation
Figure 512 W IF circuit diagram
The WIF sensor uses two electrical contac
ts exposed
to the fuel supply. When water is present i
n the fuel
supply, the circuit between the contact
sisclosed. This
allows a 5 V signal at ECM Pin X2–9. When w
ater is
not present, the circuit is open an
dECMPinX2–9will
be0V.
Fault Detection / Management
The ECM continuously monitors the
WIF circuit for
in-range faults. The ECM does not
detect open or
short circuits in the WIF circ
uit. When the ECM
detects an in-range fault, DT
C 153 will be set.
WIF Diagnostic Trouble Codes
(DTCs)
DTCs are read using the Electr
onic Service Tool (EST)
or by counting the flashes fro
m the amber and red
ENGINE lamp.
DTC 153
WIF signal out-of-range high
• DTC 153 is set when the ECM detects an in-rang
e
voltage at or above 4.5 V at ECM Pin X2–9.
• DTC 153 is set when the WIF signal circui
tis
shortedtoV
REF
or V
BAT
.
• When DTC 153 is active, the FUEL FILTER l
amp
is not illuminated.
Tools
• EST with MasterDiagnostics® soft
ware
• EZ-Tech® interface cable
• Digital Multimeter (DMM)
• Breakout Box
EGES-270-1
Read all safety instructions in the "Safety Information" section of this manual before doing any procedures.
Follow all warnings, cautions, and notes.
© August 2008 Navistar, Inc.
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