PINPOINT TEST B: THE VEHICLE DOES NOT SHIFT BETWEEN 4WD HIGH AND 4WD LOW MODES PROPERLY
Yes
REPAIR circuit 763 (O/W). CLEAR the DTCs. CYCLE the ignition OFF then ON. TEST the
system for normal operation.
No
REPLACE the GEM; REFER to
Section 419-10
. CLEAR the DTCs. TEST the system for
normal operation.
CONDITIONS
DETAILS/RESULTS/ACTIONS
B1
CHECK THE VOLTAGE OUTPUT FROM FUSE JUNCTION PANEL FUSE 15 (5A)
Measure the voltage between fuse 15 (5A) pin 1 and ground.
Is the voltage greater than 10 volts?
Yes
GO to
B4
.
No
GO to
B2
.
B2
CHECK FUSE JUNCTION PANEL FUSE 15 (5A) AND POWER DISTRIBUTION BOX FUSE 22 (50A)
Fuse 15 (5A)
Fuse 22 (50A)
Are the fuses OK?
Yes
GO to
B3
.
No
REPLACE the fuse(s). CLEAR the DTCs. TEST the system for normal operation. If the fuse(s)
fail again, CHECK for a short to ground. REPAIR as necessary.
B3
CHECK CIRCUIT 1052 (T/BK) FOR VOLTAGE
Fuse Junction Panel C243
Measure the voltage between fuse junction panel C243-11, circuit 1052 (T/BK), and ground.
Page 30 of 74
1998 F-150/250 Workshop Manual
1/11/2011
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