DESCRIPTION & OPERATION
Note. This article includes Cutaway and RV Cutaway.
The 6-way power seats provide horizontal, vertical and tilt adjustments. System consists of control switch, seat regulator motor, vertical and horizontal screw drives and gear mechanism, housing assembly and necessary wiring. Seat function switches are mounted on side of seat trim panel. Power seat circuits are protected by fuses and/or circuit breakers located in fuse panel and power distribution box.
Horizontal movement is controlled by a transmission, lead screw and motor attached to the movable section of the track. Vertical drive unit is located on left side of the movable track. Vertical operation energizes center and rear armatures and vertical drive units move seat up or down. In tilt operation, armatures move front or rear vertical drive screws to adjust seat. The motor unit is serviced as an assembly.
COMPONENT LOCATIONS
| Component | Location |
|---|---|
| Air Bag Diagnostic Monitor (1) | Behind Right Kick Panel |
| Air Bag Sliding Contact | Top Of Steering Column |
| Data Link Connector | Below Driver's Side Of Instrument Panel, To Right Of Steering Column |
| Forward/Reverse Seat Motor | Front Motor In Seat Track Assembly |
| Powertrain Control Module | Left Rear Of Engine Compartment, Near Brake Master Cylinder |
| Seat Control Switch | Outside Seat Trim Panel |
| (1) Air bag diagnostic monitor may also be referred to as Electronic Crash Sensor (ECS) module. | |
| (1) | Air bag diagnostic monitor may also be referred to as Electronic Crash Sensor (ECS) module. |
COMPONENT LOCATIONS
TROUBLE SHOOTING
Verify customers concern by operating power seat. Visually inspect for obvious signs of mechanical and electrical damage. If no visual damage is evident, diagnose by symptom. See SYMPTOM INDEX table under SYSTEM TESTS. Before performing individual component tests or system tests, check the following for possible cause of system malfunction
- Blown fuse.
- Loose or corroded connectors.
- Damaged wiring.
- Damaged motors.
- Faulty switches.
- Seat track.
SYSTEM TESTS
Note. Before beginning system testing, perform TROUBLE SHOOTING .
Verify customer complaint by operating power seat. Visually inspect for obvious sign of mechanical and electrical damage. If no visual damage is evident, repair by symptom. See SYMPTOM INDEX . A digital volt-ohmmeter is required to test the power seat system. See WIRING DIAGRAMS for terminal numbers.
SYMPTOM INDEX
TEST A: POWER SEAT INOPERATIVE
Note. Before beginning this test, ensure seat and seat track are free from all obstructions.
- Disconnect seat control switch harness connector. Measure voltage between ground and seat control switch harness connector terminal No. 3 (Black/White wire). (Scheme 1) If battery voltage exists, repair short to power in Black/White wire. If battery voltage does not exist, go to next step.
- Measure resistance between ground and seat control switch harness connector terminal No. 1 (Black wire). If resistance is less than 5 ohms, replace seat control switch. If resistance 5 ohms or more, repair open in Black wire.
Scheme 1
TEST B: POWER SEAT NOISY
Ensure ignition is off. Check alignment of seat track to floor and seat bottom. If seat track is out of alignment, align seat track. If seat track is not out of alignment, replace seat track assembly.
TEST C: POWER SEAT LOOSE
Check fastening hardware for proper installation. If hardware is loose, tighten hardware. If hardware is not loose, replace seat track assembly.
TEST D: POWER SEAT DOES NOT MAKE FULL TRAVEL
Remove driver's seat. See SEAT ASSEMBLY under REMOVAL & INSTALLATION. Check for any obstructions in seat track. If any obstructions exist, remove obstructions and grease seat track. If no obstructions exist, replace seat track assembly.
TEST E: HORIZONTALLY/VERTICALLY OPERATION INOPERATIVE
Note. Before beginning this test, ensure seat and seat track are free from all obstructions.
- Operate seat in all directions. If seat does not move horizontally, go to next step. If seat does not move vertically, go to step 5.
- Disconnect forward/reverse seat motor harness connector. Forward/reverse seat motor is first motor from front of seat. Measure voltage between forward/reverse seat motor harness connector Yellow/White and Red/White wires. Operate seat control switch in both horizontal directions, while observing voltmeter. If voltage does not change from less than -10 volts to more than 10 volts, go to next step. If voltage changes from less than -10 volts to more than 10 volts, replace seat track assembly.
- Disconnect seat control switch harness connector. Measure resistance of Yellow/White wire between seat control switch harness connector terminal No. 5 and forward/reverse seat motor harness connector. (Scheme 1) Resistance should be less than 5 ohms. Measure resistance between ground and seat control switch harness connector terminal No. 5 (Yellow/White wire). Resistance should be more than 10 k/ohms. If resistance is as specified, go to next step. If resistance is not as specified, repair open or short to ground in Yellow/White wire.
- Measure resistance of Red/White wire between seat control switch harness connector terminal No. 2 and forward/reverse seat motor harness connector. Resistance should be less than 5 ohms. Measure resistance between ground and seat control switch harness connector terminal No. 2 (Red/White wire). Resistance should be more than 10 k/ohms. If resistance is as specified, replace seat control switch. If resistance is not as specified, repair open or short to ground in Red/White wire.
- Operate tilting functions. If only forward tilting function works, go to next step. If only rear tilting function works, go to step 9. If no tilting functions work, replace seat control switch.
- Disconnect rear tilt seat motor harness connector. Measure voltage between rear tilt seat motor harness connector Red/Light Green and Yellow/Light Green wires. Operate seat control switch in both rear tilting directions, while observing voltmeter. If voltage does not change from less than -10 volts to more than 10 volts, go to next step. If voltage changes from less than -10 volts to more than 10 volts, replace seat track assembly.
- Disconnect seat control switch harness connector. Measure resistance of Red/Light Green wire between seat control switch harness connector terminal No. 4 and rear tilt seat motor. (Scheme 1) Resistance should be less than 5 ohms. Measure resistance between ground and seat control switch harness connector terminal No. 4 (Red/Light Green wire). Resistance should be more than 10 k/ohms. If resistance is as specified, go to next step. If resistance is not as specified, repair open or short to ground in Red/Light Green wire.
- Measure resistance of Yellow/Light Green wire between seat control switch harness connector terminal No. 7 and rear tilt seat motor harness connector. Resistance should be less than 5 ohms. Measure resistance between ground and seat control switch harness connector terminal No. 7 (Yellow/Light Green wire). Resistance should be more than 10 k/ohms. If resistance is as specified, replace seat control switch. If resistance is not as specified, repair open or short to ground in Yellow/Light Green wire.
- Disconnect front tilt seat motor harness connector. Measure voltage between front tilt seat motor harness connector Red/Light Blue and Yellow/Light Blue wires. Operate seat control switch in both front tilting directions, while observing voltmeter. If voltage does not change from less than -10 volts to more than 10 volts, go to next step. If voltage changes from less than -10 volts to more than 10 volts, replace seat track assembly.
- Disconnect seat control switch harness connector. Measure resistance of Red/Light Blue wire between seat control switch harness connector terminal No. 6 and front tilt seat motor. (Scheme 1) Resistance should be less than 5 ohms. Measure resistance between ground and seat control switch harness connector terminal No. 6 (Red/Light Blue wire). Resistance should be more than 10 k/ohms. If resistance is as specified, go to next step. If resistance is not as specified, repair open or short to ground in Red/Light Blue wire.
- Measure resistance of Yellow/Light Blue wire between seat control switch harness connector terminal No. 8 and front tilt seat motor harness connector. Resistance should be less than 5 ohms. Measure resistance between ground and seat control switch harness connector terminal No. 8 (Yellow/Light Blue wire). Resistance should be more than 10 k/ohms. If resistance is as specified, replace seat control switch. If resistance is not as specified, repair open or short to ground in Yellow/Light Blue wire.
COMPONENT TESTS
Note. Some individual component testing is not available from manufacturer. See SYMPTOM CHART table under SYSTEM TESTS.
SEAT CONTROL SWITCH
Remove seat control switch and disconnect harness connector. Measure resistance between seat control switch terminals with switch in appropriate position. See SEAT CONTROL SWITCH RESISTANCE table. (Scheme 2) If resistance is not as specified, replace seat control switch.
| Switch Position | Between Terminals No. | Ohms |
|---|---|---|
| Neutral (1) | 1 & 3 | More Than 5 |
| Entire Seat Down | 1, 7 & 8; 3, 4 & 6 | Less Than 5 |
| Entire Seat Up | 1, 4 & 6; 3, 7 & 8 | Less Than 5 |
| Forward | 1 & 2; 3 & 5 | Less Than 5 |
| Rearward | 1 & 5; 2 & 3 | Less Than 5 |
| Front Down | 1 & 8; 3 & 6 | Less Than 5 |
| Front Up | 1 & 6; 3 & 8 | Less Than 5 |
| Rear Down | 1 & 7; 3 & 4 | Less Than 5 |
| Rear Up | 1 & 4; 3 & 7 | Less Than 5 |
| (1) Resistance between terminal No. 1 and all other terminals (except terminal No. 3) should be less than 5 ohms. | ||
| (1) | Resistance between terminal No. 1 and all other terminals (except terminal No. 3) should be less than 5 ohms. |
SEAT CONTROL SWITCH RESISTANCE
Scheme 2
REMOVAL & INSTALLATION
| CAUTION | When battery is disconnected, vehicle computer and memory systems may lose memory data. Driveability problems may exist until computer systems have completed a relearn cycle. See COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION before disconnecting battery. |
| WARNING | On vehicle with automatic seat belt tensioner, the back-up power supply must be depleted before repairs are performed. |
Disconnect negative battery cable and wait one minute before proceeding with removal. Remove seat track lower shield, if equipped. Remove insulators covering mounting nuts and/or bolts. Remove mounting nuts, bolts and washers. Lift seat slightly and disconnect harness connectors. Remove seat assembly. To install, reverse removal procedure.
SEAT CUSHION
Note. Procedure may vary slightly depending on seat size and power options.
- Remove seat and track assembly. See «SEAT ASSEMBLY»(/ford/econoline/i-1985-2013/remont/seats/#power-seats) . Remove screws from left side shield. Carefully disconnect and tag air hoses from lumbar/bolster support switches, if equipped. Disconnect switch-to-motor connectors. Remove left side shield. Remove remaining shields.
- Remove hog rings securing lower portion of seatback cover. Slide seatback cover up enough to remove seatback frame bolts. Remove seatback. Disconnect air line from lumbar and bolster bladders, if equipped. Remove hog rings securing cover rods to seat frame. Remove cover and cushion. To install, reverse removal procedure.
Power seat motors are not serviceable. If power seat motor is defective, entire seat track assembly must be replaced. See SEAT CUSHION . Remove 2 retaining nuts to right seat track, by using fastener access holes. Remove 3 retaining nuts to left seat track. Gently pull power seat connectors from seat support. Remove seat support from seat track. Remove retaining bolts securing seat track to seat cushion. Remove 2 front seat track nuts securing seat track to seat cushion. Disconnect power seat motor connector. Remove seat track from seat cushion. To install, reverse removal procedure. Tighten retaining nuts and bolts to specifications. See TORQUE SPECIFICATIONS .
Disconnect negative battery cable an wait one minute before proceeding with removal. Remove side shield retaining screws. Remove side shield. Remove 2 switch retaining screws. Remove switch and housing. Disconnect electrical connector. Remove control switch. To install, reverse removal procedure.
TORQUE SPECIFICATIONS
| Application | Ft. Lbs. (N.m) |
|---|---|
| Front Seat Track-To Seat Cushion Nuts | 25-34 (34-46) |
| Left Front Seat Track Support Bolts | 25-34 (34-46) |
| Right Front Seat Track Support Bolts | 25-34 (34-46) |
| Seat Track Mounting Bolts | 34-46 (46-63) |
| Seat Track-To-Seat Cushion Bolts | 25-34 (34-46) |
TORQUE SPECIFICATIONS
See also:
• SYMPTOM INDEX
• TROUBLE SHOOTING
• A
• B
• C
• D
• E
• SEAT CUSHION