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Is the resistance greater than 10,000 ohms?

 

Yes

 

GO to 

B16

 

No

 

REPAIR circuit 780 (DB). CLEAR the DTCs. TEST the system for normal operation. 

 

B16

 CHECK CIRCUIT 780 (DB) FOR SHORT TO POWER

 

 

 

 

Measure the voltage between GEM C241-8, circuit 780 (DB), and ground. 

 

Is any voltage indicated?

 

Yes

 

REPAIR circuit 780 (DB). CLEAR the DTCs. TEST the system for normal operation. 

 

No

 

GO to 

B17

 

B17

 CHECK CIRCUIT 682 (DB) FOR OPEN

 

 

 

 

GEM C239 

 

 

Measure the resistance between mode switch C230-2, circuit 682 (DB), and GEM C239-21, 

circuit 682 (DB). 

 

Is the resistance less than 5 ohms?

 

Yes

 

GO to 

B18

 

No

 

REPAIR circuit 682 (DB). CLEAR the DTCs. TEST the system for normal operation. 

 

B18

 CHECK CIRCUIT 682 (DB) FOR SHORT TO GROUND

 

Measure the resistance between GEM C239-21, circuit 682 (DB), and ground. 

Page 36 of 74

1998 F-150/250 Workshop Manual

1/11/2011

http://www.fordtechservice.dealerconnection.com/pubs/con...

Summary of Contents for 1998 F-150

Page 1: ...l Shift on the Fly ESOF Vacuum Schematic 4WD Tables Table 1 4WD Mode Switch Input Resistances SECTION 308 07A Transfer Case General Information 1998 F 150 250 Workshop Manual DIAGNOSIS AND TESTING Pro...

Page 2: ...PASSED retrieve and record the continuous diagnostic trouble codes DTCs erase the continuous DTCs and perform self test diagnostics for the GEM 6 If the DTCs retrieved are related to the concern go t...

Page 3: ...or Section 413 01B B1428 Safety Belt Lamp Circuit Open or Short to Ground GEM REFER to Section 413 01A or Section 413 01B B1431 Wiper RUN PARK Relay Coil Circuit Open or Short to Ground GEM REFER to S...

Page 4: ...P1867 Transfer Case Contact Plate Open or Short to Ground GEM GO to Symptom Chart P1876 Transfer Case 2 Wheel Drive Solenoid Open or Short to Ground GEM GO to Pinpoint Test C P1877 Transfer Case 2 Wh...

Page 5: ...B OFFO G 4WDSGEM 4WD Mode INVLD 2WD 4WDLOW 4WDHIGH OFFO G 4WDSOL 4WD Solenoid Status ON OFF ON B OFFO G Active Command Display Action PID LATCH PID LATCH ON OFF WINDSHIELD WIPER WIPER RLY ON OFF WIND...

Page 6: ...ze Properly But Does Engage at Rest ESOF clutch relay Transfer case electric clutch Transfer case clutch armature Hub release spring Circuitry GO to Pinpoint Test E No Communication With the Module GE...

Page 7: ...E If the vehicle is equipped with a manual transmission depress the clutch pedal while turning the ignition switch to the START position Monitor the GEM PID IGN_GEM and rotate the ignition switch 1157...

Page 8: ...GO to A41 If DTC P1867 GO to A41 If DTC P1891 GO to A41 If DTC P1876 GO to Pinpoint Test C If DTC P1877 GO to Pinpoint Test C No GO to A6 A6 CHECK THE HIGH LAMP INDICATOR TRIGGER THE GEM ACTIVE COMMAN...

Page 9: ...mode switch in the 4H position Does the GEM PID indicate 4WDHGH Yes GO to A10 No GO to A11 A10 CHECK THE 4WD MODE SWITCH MONITOR THE GEM PID 4WDSGEM 4L Place the mode switch in the 4L position Does th...

Page 10: ...the mode switch REFER to Section 308 07B CLEAR the DTCs TEST the system for normal operation A12 CHECK THE 4WD MODE SWITCH 4H Place the mode switch in the 4H position Measure the resistance between th...

Page 11: ...08 07B CLEAR the DTCs TEST the system for normal operation A14 CHECK CIRCUIT 780 DB FOR OPEN GEM C241 Measure the resistance between mode switch C230 3 circuit 780 DB and GEM C241 8 circuit 780 DB Is...

Page 12: ...DB and ground Is any voltage indicated Yes REPAIR circuit 780 DB CLEAR the DTCs TEST the system for normal operation No GO to A17 A17 CHECK CIRCUIT 682 DB FOR OPEN GEM C239 Measure the resistance bet...

Page 13: ...de switch C230 2 circuit 682 DB and ground Is any voltage indicated Yes REPAIR circuit 682 DB CLEAR the DTCs TEST the system for normal operation No REPLACE the GEM REFER to Section 419 10 CLEAR the D...

Page 14: ...n due to viscous drag in the transfer case especially if cold If this occurs the front driveline can easily be stopped Place the mode switch in the 2H position Only the rear driveshaft should spin Doe...

Page 15: ..._CCW and MTR_CW indicate OFF Yes GO to A33 No If the GEM PID displays OFFO G GO to A26 A26 CHECK THE VOLTAGE TO THE TRANSFER CASE SHIFT RELAYS COILS CIRCUIT 704 DG LG Transfer Case Shift Relays C221 M...

Page 16: ...rmal operation A29 CHECK CIRCUITS 781 O LB AND 782 BR W FOR SHORT S TO GROUND Measure the resistance between transfer case shift relays C221 8 circuit 782 BR W and ground and between transfer case shi...

Page 17: ...icated Yes REPAIR circuit 781 O LB CLEAR the DTCs TEST the system for normal operation No GO to A32 A32 CHECK THE TRANSFER CASE SHIFT RELAYS COILS Measure the resistance between the transfer case shif...

Page 18: ...O to A35 No GO to A34 A34 CHECK THE VOLTAGE TO THE TRANSFER CASE SHIFT RELAYS SWITCH CIRCUIT 704 DG LG Transfer Case Shift Relays C221 Measure the voltage between transfer case shift relays C221 3 cir...

Page 19: ...nd 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 REP...

Page 20: ...tion A39 CHECK CIRCUIT 778 O FOR OPEN Measure the resistance between transfer case shift relays C221 10 circuit 778 O and transfer case assembly C201 14 circuit 778 O Is the resistance less than 5 ohm...

Page 21: ...or normal operation A41 CHECK THE CONTACT PLATE SWITCHES Monitor the GEM PIDs PLATE_A PLATE_B PLATE_C and PLATE_D Place the mode switch in 2H and record the GEM PIDs Depress the brake pedal Place the...

Page 22: ...A not indicate OPEN Yes GO to A44 No GO to A43 A43 CHECK THE CIRCUIT 771 P Y TO THE CONTACT PLATE SWITCH A MONITOR THE GEM PID PLATE_A Connect a jumper wire between transfer case assembly C201 10 circ...

Page 23: ...tem for normal operation A45 CHECK CIRCUIT 771 P Y FOR OPEN Measure the resistance between transfer case assembly C201 5 circuit 771 P Y and GEM C241 21 Is the resistance less than 5 ohms Yes GO to A4...

Page 24: ...O to A48 A48 CHECK CIRCUIT 762 Y W FOR OPEN Measure the resistance between transfer case assembly C201 10 and GEM C241 12 circuit 762 Y W Is the resistance less than 5 ohms Yes REPLACE the GEM REFER t...

Page 25: ...241 Measure the resistance between transfer case assembly C201 1 circuit 770 W and ground Is the resistance greater than 10 000 ohms Yes REPLACE the GEM REFER to Section 419 10 CLEAR the DTCs TEST the...

Page 26: ...N TEST the system for normal operation No REPLACE the GEM REFER to Section 419 10 CLEAR the DTCs TEST the system for normal operation A54 MONITOR THE GEM PID PLATE_C FOR OPEN Monitor the GEM PID PLATE...

Page 27: ...ms Yes REPLACE the GEM REFER to Section 419 10 CLEAR the DTCs TEST the system for normal operation No REPAIR circuit 764 BR W CLEAR the DTCs CYCLE the ignition OFF then ON TEST the system for normal o...

Page 28: ...EM PID PLATE_D FOR OPEN Monitor the GEM PID PLATE_D Does the GEM PID PLATE_D not indicate OPEN Yes GO to A61 No GO to A60 A60 CHECK CIRCUIT 763 O W TO THE CONTACT PLATE SWITCH D MONITOR THE GEM PID PL...

Page 29: ...IRCUIT 763 O W FOR OPEN Measure the resistance between transfer case assembly C201 13 circuit 763 O W and GEM C241 18 circuit 763 O W Is the resistance less than 5 ohms Yes GO to A63 No REPAIR circuit...

Page 30: ...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 fuse...

Page 31: ...No REPAIR the ignition circuit s RUN ACC circuit 297 BK LB RUN circuit 1040 R LB START circuit 32 R LB or circuit 481 GY Y in question CLEAR the DTCs TEST the system for normal operation B5 RETRIEVE...

Page 32: ...C P1891 GO to B31 No GO to B6 B6 CHECK THE HIGH LAMP INDICATOR TRIGGER THE GEM ACTIVE COMMAND HIGH LAMP ON Trigger the GEM active command HIGH LAMP to ON then OFF The 4x4 indicator should illuminate t...

Page 33: ...GO to B10 No GO to B11 B10 CHECK THE 4WD MODE SELECT SWITCH MONITOR THE GEM PID 4WDSGEM 4L Place the mode switch in the 4L position Does the GEM PID indicate 4WDLOW Yes GO to B20 No GO to B11 B11 CHE...

Page 34: ...lace the mode switch in the 4H position Measure the resistance between the mode switch terminals 2 and 3 Is the resistance between 1050 and 1150 ohms Yes GO to B13 No REPLACE the mode switch REFER to...

Page 35: ...PEN GEM C241 Measure the resistance between mode switch C230 3 circuit 780 DB and GEM C241 8 circuit 780 DB Is the resistance less than 5 ohms Yes GO to B15 No REPAIR circuit 780 DB CLEAR the DTCs TES...

Page 36: ...m for normal operation No GO to B17 B17 CHECK CIRCUIT 682 DB FOR OPEN GEM C239 Measure the resistance between mode switch C230 2 circuit 682 DB and GEM C239 21 circuit 682 DB Is the resistance less th...

Page 37: ...R the DTCs TEST the system for normal operation No REPLACE the GEM REFER to Section 419 10 CLEAR the DTCs TEST the system for normal operation B20 CHECK BRAKE PEDAL POSITION BPP SWITCH INPUT MONITOR T...

Page 38: ...BPP switch C252 circuit 10 LG R and circuit 511 LG Monitor the GEM PID BOO_GEM Does the GEM PID display ON Yes REPLACE the BPP switch REFER to Section 417 01 CLEAR the DTCs TEST the system for normal...

Page 39: ...Verify the GEM PID NTRL_SW displays NTRL Verify the GEM PID NTRL_SW displays notNTRL when the transmission is in any position other than NEUTRAL Do the GEM PIDs indicate correctly Yes GO to B28 No GO...

Page 40: ...ns REPLACE the GEM REFER to Section 419 10 CLEAR the DTCs TEST the system for normal operation B27 CHECK THE VEHICLE SPEED SENSOR VSS MONITOR THE GEM PID VSS_GEM Monitor the GEM PID VSS_GEM while driv...

Page 41: ...ess than 5 ohms Yes GO to B30 No REPAIR circuit 679 GY BK CLEAR the DTCs TEST the system for normal operation B30 CHECK THE CIRCUITS BETWEEN THE GEM AND THE FUSE JUNCTION PANEL GEM C267 Measure the re...

Page 42: ...the PIDs Place the mode switch in the 4L position and record the PIDs Compare the GEM PIDs with Table 4 Contact Plate Sensor Position Codes refer to 4WD Tables Do the GEM PIDs agree with Table 4 Yes...

Page 43: ...Y FOR SHORT TO GROUND Measure the resistance between GEM C241 21 circuit 771 P Y and ground Is the resistance greater than 10 000 ohms Yes REPLACE the GEM REFER to Section 419 10 CLEAR the DTCs TEST t...

Page 44: ...the system for normal operation No GO to B37 B37 CHECK CIRCUIT 762 Y W FOR SHORT TO POWER Measure the voltage between GEM C241 12 circuit 762 Y W and ground Is any voltage indicated Yes REPAIR circui...

Page 45: ...770 W TO THE CONTACT PLATE SWITCH B MONITOR THE GEM PID PLATE_B Connect a jumper wire between transfer case assembly C201 1 circuit 770 W and C201 10 circuit 762 Y W Monitor the GEM PID PLATE_B Does t...

Page 46: ...stance between transfer case assembly C201 1 circuit 770 W and GEM C241 20 circuit 770 W Is the resistance less than 5 ohms Yes GO to B43 No REPAIR circuit 770 W CLEAR the DTCs CYCLE the ignition OFF...

Page 47: ...R THE GEM PID PLATE_C Connect a jumper wire between transfer case assembly C201 9 circuit 764 BR W and C201 10 circuit 762 Y W Monitor the GEM PID PLATE_C Does the GEM PID PLATE_C indicate CLOSED Yes...

Page 48: ...ation B48 CHECK CIRCUIT 764 BR W FOR SHORT TO POWER Measure the voltage between transfer case assembly C201 9 circuit 764 BR W and ground Is any voltage indicated Yes REPAIR circuit 764 BR W CLEAR the...

Page 49: ...tem for normal operation No GO to B52 B51 CHECK CIRCUIT 763 O W FOR SHORT TO GROUND GEM C241 Measure the resistance between GEM C241 18 circuit 763 O W and ground Is the resistance greater than 10 000...

Page 50: ...er case assembly C201 13 circuit 763 O W and ground Is any voltage indicated Yes REPAIR circuit 763 O W CLEAR the DTCs CYCLE the ignition OFF then ON TEST the system for normal operation No REPLACE th...

Page 51: ...er than 10 volts Yes REPLACE the fuse junction panel CLEAR the DTCs TEST the system for normal operation No REPAIR circuit 1052 T BK CLEAR the DTCs TEST the system for normal operation C4 CHECK THE IG...

Page 52: ...st A If DTC P1820 GO to Pinpoint Test A If DTC P1822 GO to Pinpoint Test A If DTC P1824 GO to Pinpoint Test E If DTC P1826 GO to Pinpoint Test E If DTC P1828 GO to Pinpoint Test A If DTC P1830 GO to P...

Page 53: ...ne running refer to Section 100 02 Spin one front tire The other front tire should spin in the opposite direction Is the axle disconnect working properly Yes EXIT the active command modes LOWER the ve...

Page 54: ...o GO to C12 C12 CHECK 4WD AND 2WD VACUUM HUB SOLENOID CIRCUITS MONITOR THE GEM PIDS 4WDSOL AND 2WDSOL Monitor the GEM PIDs 4WDSOL and 2WDSOL while triggering the GEM active commands AXLE ENGG and AXLE...

Page 55: ...VACUUM SOLENOIDS MONITOR THE GEM PIDS 4WDSOL AND 2WDSOL Monitor the GEM PIDS 4WDSOL and 2WDSOL while triggering the GEM active commands AXLE ENGG and AXLE DSCN to ON Do the GEM PIDS 4WDSOL and 2WDSOL...

Page 56: ...17 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 s...

Page 57: ...05 R and 4WD vacuum solenoid C180 circuit 605 R Is the resistance less than 5 ohms Yes GO to C21 No REPAIR circuit 605 R CLEAR the DTCs TEST the system for normal operation C21 CHECK CIRCUIT 145 GY BK...

Page 58: ...question CLEAR the DTCs TEST the system for normal operation C24 CHECK THE 4WD AND 2WD VACUUM SOLENOIDS CLOSED Connect Vacuum Pump to the feed line of the vacuum solenoid being tested Monitor the GEM...

Page 59: ...e 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...

Page 60: ...rcuit 1052 T BK CLEAR the DTCs TEST the system for normal operation D4 CHECK THE IGNITION STATES MONITOR THE GEM PID IGN_GEM NGS NOTE If the vehicle is equipped with a manual transmission depress the...

Page 61: ...If DTC P1832 GO to Pinpoint Test C If DTC P1834 GO to Pinpoint Test C If DTC P1838 GO to Pinpoint Test A If DTC P1846 GO to Pinpoint Test A or B If DTC P1850 GO to Pinpoint Test A or B If DTC P1854 GO...

Page 62: ...SHORT TO GROUND Instrument Cluster C236 Measure the resistance between 4x4 HIGH GEM C241 9 circuit 210 LB and ground 4x4 LOW GEM C241 10 circuit 975 BR Y and ground Are the resistances greater than 1...

Page 63: ...ONITOR THE GEM PIDS 4WDHIGH AND 4WDLOW Monitor the GEM PIDs 4WDHIGH and or 4WDLOW while triggering the GEM active commands HIGH LAMP and LOW LAMP to ON Does the PID indicate ON B Yes REPLACE the GEM R...

Page 64: ...inpoint Test A If DTC P1846 GO to Pinpoint Test A or B If DTC P1850 GO to Pinpoint Test A or B If DTC P1854 GO to Pinpoint Test A or B If DTC P1858 GO to Pinpoint Test A or B If DTC P1876 GO to Pinpoi...

Page 65: ...o ON Does the GEM PID 4WDELCL indicate ON Yes GO to E7 No If the PID displays ON B GO to E5 E5 CHECK THE ESOF CLUTCH RELAY ESOF Clutch Relay Check the ESOF clutch relay refer to Component Test Is the...

Page 66: ...D 4WDELCL indicate OFF Yes GO to E12 No If the PID displays OFFO G GO to E8 E8 CHECK THE VOLTAGE TO THE ESOF CLUTCH RELAY COIL CIRCUIT 294 W LB ESOF Clutch Relay Measure the voltage between ESOF clutc...

Page 67: ...Yes GO to E11 No REPAIR circuit 976 O CLEAR the DTCs TEST the system for normal operation E11 CHECK CIRCUIT 976 O FOR OPEN Measure the resistance between ESOF clutch relay connector pin 2 circuit 976...

Page 68: ...E15 E13 CHECK CIRCUIT 779 BR FOR VOLTAGE DE ENERGIZED Transfer Case Assembly C201 Trigger the GEM active command SHFT CLCH to OFF Measure the voltage between transfer case assembly C201 16 circuit 77...

Page 69: ...AGE ESOF Clutch Relay Measure the voltage between ESOF clutch relay connector pin 3 circuit 704 DG LG and ground Is the voltage greater than 10 volts Yes GO to E16 No CHECK power distribution box fuse...

Page 70: ...front axle Remove the front driveshaft refer to Section 205 01 Place the mode switch in the 2H position Rotate the tires between 20 and 25 mph 32 40 kph and shift into 4H Does the front output of the...

Page 71: ...al operation F2 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 F3 No GO to F5 F3 CHECK CIRCUIT 1052 T BK FOR VOLTAGE Fuse...

Page 72: ...HECK FUSE JUNCTION PANEL FUSE 15 5A AND POWER DISTRIBUTION BOX FUSE 22 50A GEM DISCONNECTED GEM C267 Replace the failed fuses Fuse 15 5A Fuse 22 50A Are the fuses OK Yes GO to F7 No If fuse 22 50A fai...

Page 73: ...nel C243 terminal 11 and fuse junction panel C267 terminal 16 Are the resistances less than 5 ohms Yes GO to F8 No REPLACE the fuse junction panel CLEAR the DTCs TEST the system for normal operation F...

Page 74: ...eration F10 CHECK THE FUSE JUNCTION PANEL FOR SHORT TO GROUND Measure the resistance between fuse junction panel C267 terminal 4 and ground Is the resistance greater than 10 000 ohms Yes REFER to Sect...

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