Symptom Chart
IGN_GEM 297 (BK/LG), 1040 (R/LB), 32 (R/LB), 687 (GY/Y) Ignition Switch States START, RUN, OFF, ACC
IGN_KEY 158 (BK/PK) Ignition Key-In/Out IN, OUT
INTLMP 402 (O/LG) Fuse Junction Panel (Internal) Interior Lamp Relay Circuit ON---, OFF---, ON-B-, ON O-G
LGATE_SW 700 (W/PK) Liftgate/Glass Switch Status AJAR, CLOSED
LRDR_SW 363 (BK/LB) LR Door Open Warning Lamp Switch AJAR, CLOSED
MTR_CCW 781 (O/LB) HI to LO Shift Relay Coil Status ON---, OFF---, ON-B-, OFFO-G
MTR_CW 782 (BR/W) LO to HI Shift Relay Coil Status ON---, OFF---, ON-B-, OFFO-G
NTRL_SW 463 (R/W) Transmission Range Sensor Input NTRL, not NTRL
P_DR_SW 345 (BK/PK) RH Door Open Warning Lamp Switch AJAR, CLOSED
PARK_SW 257 (W/R) Headlamp Control Input Switch ON - OFF
PLATE_A 771 (P/Y) Transfer Case Contact Plate Switch A OPEN, CLOSED
PLATE_B 770 (W) Transfer Case Contact Plate Switch B OPEN, CLOSED
PLATE_C 764 (BR/W) Transfer Case Contact Plate Switch C OPEN, CLOSED
PLATE_D 763 (O/W) Transfer Case Contact Plate Switch D OPEN, CLOSED
PLATEPW 762 (Y/W) Contact Plate Ground Output ON---, OFF---, ON-B-, OFFO-G
PWR_RLY 239 (W/O) ABS Active Input (A4WD Only) ON, OFF
R_WP_DN 592 (T) Rear Wiper DOWN Relay Status ON---, OFF---, ON-B-, OFF O-G
R_WP_MD 485 (PK/BK) Rear Wiper Mode Switch Status LOW, HIGH, WASH, OFF
R_WP_PK 587 (P/Y) Rear Wiper Park Sense PARK, notPRK
R_WP_SW 488 (DG) Rear Washer Relay Output ON---, OFF---, ON-B-, OFFO-G
R_WP_UP 591 (LG) Rear Wiper UP Relay Status ON---,OFF---, ON-B-, OFFO-G
RB_LMP 1008 (LG/O) Running Board Lamp Output Status OFF---, ON---, OFFO-G, ON-B-
RRDR_SW 346 (BK/W) RR Door Open Warning Lamp Switch AJAR, CLOSED
SBLTLMP 450 (DG/LG) Safety Belt Warning Indicator ON ---, OFF ---, ON-B-, OFFO-G
SPEEDWP N/A Speed Dependent Wiper Function ACTIVE, notACT
TRA_FSP 435 (Y/LB) Front Shaft Speed 0-225 KPH
TRA_RSP 772 (LB) Rear Shaft Speed 0-255 KPH
VSS_GEM 676 (PK/O), 679 (GY/BK) Vehicle Speed Sensor 0-255 KPH
WASH_SW 686 (T/R) Front Washer Relay Output ON---, OFF---, ON-B-, OFFO-G
WFL_LMP 82 (PK/Y) Low Washer Fluid Warning Indicator Circuit ON---, OFF---, ON-B-, OFFO-G
WFLUID 81 (R/LG) Low Washer Fluid Switch LOW, OK
WPHISP 647 (GY/LB) Front Wiper HI/LO Relay Status ON---, OFF---, ON-B-, OFFO-G
WPMODE 680 (LB/O), 684 (PK/Y) Front Wiper/Washer Switch Status WASH, OPEN, INVLD, OFF, INTVL1-7, LOW, HIGH
WPPK_PK N/A Front Wiper Park to Park Time 0 to 65 seconds
WPPRKSW 671 (LB) Front Wiper Motor Switch Status PARKED, not PRK
WPRUN 646 (Y/W) Front Windshield Wiper Run/Park Relay Status ON---, OFF---, ON- B-, OFFO-G
2WDSOL 145 (GY/BK) 2WD Solenoid Status ON---, OFF---, ON-B-, OFFO-G
4WD_LMP 994 (W) A4WD Indicator Status ON---, OFF---, ON-B-, OFFO-G
4WDCLST 976 (O) Four Wheel Drive Clutch Relay Control ON---, OFF---, ON-B-, OFFO-G
4WDHIGH 777 (Y) 4WD High Indicator Status ON---, OFF---, ON-B-, OFFO-G
4WDLOW 778 (O) 4WD Low Indicator Status ON---, OFF---, ON-B-, OFFO-G
4WDSGEM 780 (DB) 4WD Mode INVLD, A42D, 2WD, 4WDLOW, 4WDHIGH, OFFO-G
4WDSOL 605 (R) 4WD Solenoid Status ON---, OFF---, ON-B-, OFFO-G
Symptom Chart
Condition Possible Sources Action
The A4WD Indicator Flashes When the A4WD Mode Is Selected
A4WD clutch relay/circuit.
Hall effect speed sensors/circuits.
Transfer case electric clutch.
4WABS module/circuit.
GEM.
GO to Pinpoint Test
A.
The Vehicle Does Not Shift Between 2WD/A4WD and 4WD Modes Properly
A4WD mode switch/circuit.
A4WD clutch relay/circuit.
Contact plate sensors A, B, C and/or D
circuits.
Transfer case shift motor/circuit.
Transfer case shift relays.
Transfer case mechanism.
GEM.
GO to Pinpoint Test
B.
The Vehicle Does Not Shift Between 4WD HIGH and 4WD LOW Modes
Properly
A4WD mode switch/circuit.
VSS.
BPP switch.
Transfer case shift relays.
Transfer case mechanism.
Transmission range sensor.
GEM.
Digital transmission range (DTR) sensor.
GO to Pinpoint Test
C.
The Front Axle Is Not Engaging Properly (Transfer Case Motor Movement
OK)
4x4 solenoid/circuit.
4x2 solenoid/circuit.
Vacuum motor.
Vacuum lines.
Front differential mechanism.
GO to Pinpoint Test
D.
1998 Expedition/Navigator Workshop Manual
http://www.fordtechservice.dealerconnection.com/pubs/content/~WSWJ/~MUS~LEN/21/