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2WD Vacuum Solenoid C181
Measure the voltage between 4WD vacuum solenoid C180, circuit 294 (W/LB), and ground;
and between 2WD vacuum solenoid C181, circuit 294 (W/LB), and ground.
Are the voltages greater than 10 volts?
Yes
GO to
C17
.
No
REPAIR circuit 294 (W/LB) or REPLACE fuse junction panel fuse 23 (10A). CLEAR the DTCs.
TEST the system for normal operation.
C17
CHECK THE 4WD VACUUM SOLENOID FOR CONTINUITY
Measure the resistance between 4WD vacuum solenoid terminals 1 and 2.
Is the resistance between 50 and 100 ohms?
Yes
GO to
C18
.
No
REPLACE the 4WD vacuum solenoid. CLEAR the DTCs. TEST the system for normal
operation.
C18
CHECK THE 2WD VACUUM SOLENOID FOR CONTINUITY
Measure the resistance between 2WD vacuum solenoid terminals 1 and 2.
Is the resistance between 50 and 100 ohms?
Yes
GO to
C19
.
No
Page 56 of 74
1998 F-150/250 Workshop Manual
1/11/2011
http://www.fordtechservice.dealerconnection.com/pubs/con...