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Home >> Ford Truck >> 2012 >> Explorer FWD L4-2.0L Turbo >> Repair and Diagnosis >> Body and Frame >> Seats >> Testing and Inspection >> Pinpoint Tests >> Seating - 3rd Row >> Diagnostic Routine F

Diagnostic Routine F




Diagnostic Routine F

Diagnostic Overview

Power-Fold Seat Motor (Backrest) and Sensor Functional Test - RH

Refer to Wiring Diagram Set 120 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

The PFSM (Power-Fold Seat Module) supplies voltage and ground to the power-fold seat motor to move the seat to and from the FOLD and NORMAL positions when selected by the seat control switch. When FOLD is selected, the backrest folds forward and releases the spring loaded headrest. If an obstruction is detected in the FOLD/NORMAL range of movement, the seat stops, reverses movement a few inches and then stops again until the obstruction is removed. When the obstruction has been removed, the seat control switch must be pressed again to reset the request. The seat goes to the power-fold seat motor home position (seat folded and latched to floor) and then continues with any seat position requested. If the PFSM (Power-Fold Seat Module) detects a power-fold seat motor circuit fault (open or short), motor operation is disabled. If a short to ground is present, the motor works in only one direction

A Hall-effect sensor is located inside each of the power-fold seat motor assemblies to detect motor movement and seat position to the PFSM (Power-Fold Seat Module). If the sensor does not detect motor movement during a request from the seat control switch, the PFSM (Power-Fold Seat Module) disables the power-fold seat motor output.

Visual Inspection and Diagnostic Pre-checks

Verify good battery condition before diagnosing the PFSM (Power-Fold Seat Module) system. Poor battery condition may interfere with PFSM (Power-Fold Seat Module) operation. If battery voltage drops below 10 volts, seat movement does not start. If battery voltage drops below 8 volts, a started seat movement stops.

Pinpoint Test

NOTE: Verify good battery condition before diagnosing the PFSM (Power-Fold Seat Module) system. Poor battery condition may interfere with PFSM (Power-Fold Seat Module) operation. If battery voltage drops below 10 volts, seat movement will not start. If battery voltage drops below 8 volts, a started seat movement will stop.

NOTE: The battery saver relay system will time-out after 10 minutes and disable the third row power seat operation. Meter voltage measurements will be inaccurate when this occurs, which could lead to misdiagnosis. To enable the battery saver relay system during diagnosis and testing, close and open any vehicle door.

1. CHECK THE PFSM (Power-Fold Seat Module) FOR OUTPUT VOLTAGE TO THE POWER-FOLD SEAT MOTOR
NOTICE: The following pinpoint test uses a test light to simulate normal circuit loads. Use only the test light recommended in the Special Tools table at the beginning. To avoid connector terminal damage, use the Flex Probe Kit for the test light probe connection to the vehicle. Do not use the test light probe directly on any connector.

NOTICE: This pinpoint test step directs testing circuits using a back-probe method. Use the special back-probe tool specified in the tool list. Do not force test leads or other probes into connectors. Adequate care must be exercised to avoid connector terminal damage while making sure that good electrical contact is made with the circuit or terminal. Failure to follow these instructions may cause damage to wiring, terminals, or connectors and subsequent electrical faults.

1. Access the PFSM (Power-Fold Seat Module). To access the PFSM (Power-Fold Seat Module), REFER to Power-Fold Seat Module (PFSM) .

2. Verify the vehicle is in PARK and the liftgate is open.

3. Verify the courtesy lights are on. If needed, close and open any door on the vehicle.

4. Measure:





5. Press the NORMAL button, then the FOLD button, and monitor the test light and allow the seat to complete any movement.

6. If the seat is already in the normal position, press the FOLD button instead.

Does the test light illuminate momentarily when either button is pressed?








2. CHECK THE RH (Right Hand) POWER-FOLD SEAT MOTOR AND CIRCUITS FOR A SHORT TO GROUND

1. Disconnect: PFSM (Power-Fold Seat Module) C4250B.

2. Measure:





Are the resistances greater than 10,000 ohms?








3. CHECK THE RH (Right Hand) POWER-FOLD SEAT MOTOR AND CIRCUITS FOR A SHORT TO GROUND

1. Disconnect: RH (Right Hand) Power-Fold Seat Motor.

- Remove the backrest latch outer cover to gain access to the RH (Right Hand) power-fold seat motor electrical connector. REFER to Seat - Exploded View .

2. Measure:





Are the resistances greater than 10,000 ohms?








4. CHECK THE RH (Right Hand) POWER-FOLD SEAT MOTOR AND CIRCUITS FOR AN OPEN

1. Disconnect: PFSM (Power-Fold Seat Module) C4250B.

2. NOTE: Typical motor resistance is 1.5 ohms.
Measure:





Is the resistance less than 5 ohms?








5. CHECK THE RH (Right Hand) POWER-FOLD SEAT MOTOR CIRCUITS FOR AN OPEN

1. Disconnect: RH (Right Hand) Power-Fold Seat Motor.

- Remove the backrest latch outer cover to gain access to the RH (Right Hand) power-fold seat motor electrical connector. REFER to Seat - Exploded View .

2. Measure:





Are the resistances less than 3 ohms?








6. CHECK THE PFSM (Power-Fold Seat Module) FOR OUTPUT VOLTAGE TO THE FOLD SENSOR
NOTICE: This pinpoint test step directs testing circuits using a back-probe method. Use the special back-probe tool specified in the tool list. Do not force test leads or other probes into connectors. Adequate care must be exercised to avoid connector terminal damage while making sure that good electrical contact is made with the circuit or terminal. Failure to follow these instructions may cause damage to wiring, terminals, or connectors and subsequent electrical faults.

1. Connect: PFSM (Power-Fold Seat Module) C4250B.

2. Verify the vehicle is in PARK and the liftgate is open.

3. Verify the courtesy lights are on. If needed, close and open any door on the vehicle.

4. Measure:





Is the voltage greater than 5 volts?








7. CHECK THE RH (Right Hand) POWER-FOLD SEAT MOTOR SENSOR AND CIRCUITS FOR A SHORT TO GROUND

1. Disconnect: PFSM (Power-Fold Seat Module) C4250B.

2. Disconnect: RH (Right Hand) Power-Stow Seat Motor.

- Remove the backrest latch outer cover to gain access to the RH (Right Hand) power-stow seat motor electrical connector. REFER to Seat - Exploded View .

3. Measure:





Is the resistance greater than 10,000 ohms?








8. CHECK THE RH (Right Hand) POWER-FOLD SEAT MOTOR SENSOR CIRCUITS FOR A SHORT TO GROUND

1. Disconnect: RH (Right Hand) Power-Fold Seat Motor.

- Remove the backrest latch outer cover to gain access to the power-fold seat motor electrical connector. REFER to Seat - Exploded View .

2. Measure:





Are the resistances greater than 10,000 ohms?








9. CHECK THE RH (Right Hand) POWER-FOLD SEAT MOTOR SENSOR CIRCUITS FOR AN OPEN

1. Disconnect: RH (Right Hand) Power-Fold Seat Motor.

- Remove the backrest latch outer cover to gain access to the power-fold seat motor electrical connector. REFER to Seat - Exploded View .

2. Disconnect: PFSM (Power-Fold Seat Module) C4250B.

3. Measure:





Are the resistances less than 3 ohms?








10. CHECK PFSM (Power-Fold Seat Module) CONNECTORS AND PINS FOR DAMAGE AND RETEST THE SYSTEM

1. Disconnect and inspect all PFSM (Power-Fold Seat Module) connectors.

2. Repair:

- corrosion (install new connector or terminals - clean module pins)
- damaged or bent pins - install new terminals/pins as necessary
- pushed-out pins - install new pins as necessary

3. Reconnect all previously disconnected electrical connectors.

4. Operate the seats and determine if the concern is still present.

Is the concern still present?







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