PINPOINT TEST D: THE 4X4 HIGH AND/OR 4X4 LOW RANGE INDICATOR DO/DOES NOT OPERATE PROPERLY
Trigger the GEM active commands AXLE ENGG and AXLE DSCN to ON.
Apply vacuum and verify that the vacuum solenoids are open.
Are the solenoids open?
Yes
RELEASE the applied vacuum. GO to
C26
.
No
REPLACE the vacuum solenoid(s) in question. CLEAR the DTCs. TEST the system for normal
operation.
C26
CHECK THE VACUUM FEED LINES TO THE VACUUM MOTOR
Verify that the feed lines from the vacuum solenoids to the vacuum motor are OK.
Are the feed lines OK?
Yes
RECONNECT the vacuum lines; GO to
C27
.
No
REPAIR the feed line(s) in question. CLEAR the DTCs. TEST the system for normal operation.
C27
CHECK THE VACUUM MOTOR
Remove the linkage from the vacuum motor.
Trigger the GEM active commands AXLE ENGG to ON and AXLE DSCN to OFF.
Does the vacuum motor move to the engaged position?
Yes
REPAIR the center disconnect assembly; REFER to
Section 205-03
. CLEAR the DTCs. TEST
the system for normal operation.
No
REPAIR the vacuum motor. CLEAR the DTCs. TEST the system for normal operation.
CONDITIONS
DETAILS/RESULTS/ACTIONS
D1
CHECK THE VOLTAGE OUTPUT FROM FUSE JUNCTION PANEL FUSE 15 (5A)
Measure the voltage between fuse junction panel fuse 15 (5A) pin 1, and ground.
Is the voltage greater than 10 volts?
Yes
GO to
D4
.
Page 59 of 74
1998 F-150/250 Workshop Manual
1/11/2011
http://www.fordtechservice.dealerconnection.com/pubs/con...