B28 Check The Voltage To The Transfer Case Shift Motor — Active Command Cw/Ccw Off; B29 Check Circuits 777 (Y) And 778 (O) For Short(S) To Power; B30 Check Circuits 777 (Y) And 778 (O) For Open - Ford Expedition 1998 Workshop Manual

1998 Expedition/Navigator Workshop Manual
B28 CHECK THE VOLTAGE TO THE TRANSFER CASE SHIFT MOTOR — ACTIVE COMMAND CW/CCW OFF

B29 CHECK CIRCUITS 777 (Y) AND 778 (O) FOR SHORT(S) TO POWER

Transfer Case Shift Relays C221

B30 CHECK CIRCUITS 777 (Y) AND 778 (O) FOR OPEN

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Yes
GO to B31.
No
REPAIR circuit 704 (DG/LG). CLEAR the DTCs. TEST the system for normal operation.
NOTE: The CW/CCW active command is located in the 4-Wheel Electronic Shift active command menu.
Set the active command CW/CCW to OFF.
Measure the voltage between transfer case assembly C201-14, circuit 778 (O), and ground; and between transfer
case assembly C201-15, circuit 777 (Y), and ground.
Are the voltages greater than 10 volts?
Yes
GO to B29.
No
GO to B30.
Measure the voltage between transfer case assembly C201-14, circuit 778 (O) and ground; and between transfer
case assembly C201-15, circuit 777 (Y), and ground.
Is any voltage indicated?
Yes
REPAIR circuit 778 (O) and/or circuit 777 (Y). CLEAR the DTCs. TEST the system for normal operation.
No
REPLACE the transfer case shift relays. CLEAR the DTCs. TEST the system for normal operation.
NOTE: The CW/CCW active command is located in the 4-Wheel Electronic Shift active command menu.
Set the active command CW/CCW to OFF.
Measure the resistance between transfer case assembly C201-14, circuit 778 (O) and ground; and between
transfer case assembly C201-15, circuit 777 (Y), and ground.
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8/30/2010