Four-Wheel Drive Systems Ford Explorer Sport Trac I

GENERAL SPECIFICATION

General Specification

TORQUE SPECIFICATIONS

Torque Specifications

Scheme 1

For transfer case repair procedures, refer to TRANSFER CASE - AUTOMATIC SHIFT .

The electronic shift on the fly system is an electronically-shifted four wheel drive system that allows the operator to choose between three different modes. The operator can switch between 2WD and 4WD HIGH modes at any speed. To engage or disengage 4WD LOW range, the vehicle speed must be less than 5 km/h (3 mph), the brake depressed, and the transmission must be in NEUTRAL.

The shift motor sense plate, an integral part of the electric shift motor, informs the four-wheel drive (4WD) control module to the position of the transfer case.

The digital TR sensor is located on the LH side of the automatic transmission; this sensor informs the 4WD Control Module when the automatic transmission is in the NEUTRAL position.

The electric shift motor is mounted externally at the rear of the transfer case. It drives a rotary cam which moves the mode fork and range fork within the transfer case between the 4WD HIGH, 4WD LOW and 2WD positions.

The 4WD shift motor is controlled by the 4WD Control Module to shift the transfer case between 4WD HIGH, 4WD LOW and 2WD modes.

System Function

Feature inputs

1. Brake ON/OFF Switch
2. Mode Select Switch (MSS)
3. Digital Transmission Range (TR) Sensor
4. Vehicle Speed Signal Transmitted From Powertrain Control Module (PCM)
5. Contact Plate Position Inputs A, B, C, D

Feature outputs

1. 4WD LOW indicator (ground when activated, open circuit when deactivated).
2. 4WD HIGH indicator (ground when activated, open circuit when deactivated).
3. 4WD shift motor outputs.

Shifts between 2WD and 4WD HIGH can be made at any speed. Listed below are the inputs and outputs needed by the 4WD Control Module to execute a change between any of these modes.

Feature inputs

1. Vehicle Speed Signal
2. Mode Select Switch

Feature outputs

1. 4WD HIGH cluster indicator (ground when activated, open circuit when deactivated).

When shifting into or out of LOW range, the 4WD Control Module requires that the vehicle speed is less than 5 km/h (3 mph), the brake is applied, and the transmission is in NEUTRAL.

Feature inputs

1. Mode Select Switch
2. Contact Plate Position Inputs A, B, C, D
3. Vehicle Speed Signal
4. Brake ON/OFF switch input (battery voltage when brake is depressed, open circuit when not activated).
5. Digital transmission range sensor (ground when transmission is in NEUTRAL, open circuit otherwise).

Feature outputs

1. 4WD shift motor outputs.
2. 4WD LOW cluster indicator (ground when activated, open circuit when deactivated).

Wiring Diagrams

For Explorer Sport wiring diagrams, see TRANSMISSION in SYSTEM WIRING DIAGRAMS article. For Explorer Sport Trac wiring diagrams, see TRANSMISSION in SYSTEM WIRING DIAGRAMS article.

Scheme 2

Transfer Case - Electronic Shift

The four-wheel drive electronic shift-on-the-fly feature electrically shifts the vehicle transfer case between 2WD, 4WD HIGH, and 4WD LOW. The system mode is selected by the operator through the mode select switch (MSS) on the instrument panel. The operator is informed which mode the system is in by two instrument cluster indicators, one for 4WD HIGH which appears as 4WD HIGH, and one for 4WD LOW, which appears as 4WD LOW. Shifts into 4WD HIGH can be made at any speed. When shifting into 4WD HIGH with the vehicle stationary, tooth blockage may occur preventing shift completion. When the vehicle is driven above 8 km/h (5 mph) the shift will complete. When shifting in or out of 4WD LOW, the four-wheel drive (4WD) control module requires that the vehicle speed be less than 5 km/h (3 mph), the brake pedal be applied, and the transmission be in NEUTRAL.

The gearmotor encoder assembly is mounted externally on the transfer case. It drives a rotary cam which moves the mode fork and range fork within the transfer case between the 4WD HIGH, 4WD LOW, and 2WD range positions.

The four-wheel drive (4WD) control module controls the shift motor encoder assembly that shifts between 4WD HIGH, 4WD LOW, and 2WD modes.

The 4WD Control Module accomplishes shifts by interpreting inputs from the following

1. Mode Select Switch (MSS)
2. Vehicle Speed Signal
3. Encoder Plate Position
4. Brake Pedal Switch
5. Digital Transmission Range (TR) Sensor
6. Ignition Switch
7. Gearmotor Encoder Assembly

Based on these inputs, the 4WD Control Module controls the shifts into 2WD, 4WD HIGH or 4WD LOW with the following outputs

1. Gearmotor (Clockwise)
2. Gearmotor (Counterclockwise)

Scheme 3

1. Visually inspect for the following obvious signs of mechanical and electrical damage.
2. If the concern remains after the inspection, connect the scan tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the scan tool menu. If the scan tool does not communicate with the vehicle: Check that the program card is correctly installed. Check the connections to the vehicle. Check the ignition switch position.
3. If the scan tool still does not communicate with the vehicle, refer to the scan tool manufacturer's manual.
4. Carry out the DATA LINK DIAGNOSTICS test. If the scan tool responds with: CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to «MODULE COMMUNICATIONS NETWORK»(/ford/explorer-sport-trac/i-2000-2005/remont/communication-devices/#module-communications-network) article. NO RESP/NOT EQUIP for 4WD Control Module, go to «PINPOINT TEST B: NO COMMUNICATION WITH FOUR-WHEEL DRIVE (4WD) CONTROL MODULE»(/ford/explorer-sport-trac/i-2000-2005/remont/transfer-case/#four-wheel-drive-systems) . SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out the 4WD Control Module self-test.
5. If the DTCs retrieved are related to the concern, go to «4WD CONTROL MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX»(/ford/explorer-sport-trac/i-2000-2005/remont/transfer-case/#four-wheel-drive-systems) table to continue diagnostics.
6. If no DTCs related to the concern are retrieved, carry out the Electronic Shift Function Test. Refer to «PINPOINT TEST A: ELECTRONIC SHIFT FUNCTIONAL TEST»(/ford/explorer-sport-trac/i-2000-2005/remont/transfer-case/#four-wheel-drive-systems__pinpoint-test-a-electronic-shift-functional) .

4WD CONTROL MODULE DIAGNOSTIC TROUBLE CODE (DTC) INDEX

Pinpoint Test A: Electronic Shift Functional Test

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1. Remove the mode select switch (MSS) knob.
2. Remove the audio unit.
3. Remove the screws and pull the instrument panel center finish panel out of the instrument panel.
4. Disconnect the harness connector, remove the two screws and the MSS.
5. To install, reverse the removal procedure.

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Scheme 52

1. Set the mode select switch to the 4X4 HIGH position.
2. Raise and support the vehicle.
3. Disconnect the gearmotor encoder assembly harness connector.
4. Remove the bracket bolt and the gearmotor encoder assembly mounting bolts and remove the gearmotor encoder assembly.
5. Remove the grease from the motor adapter and check for any nicks or burrs. If any damage is found, repair or install a new gearmotor encoder assembly as necessary. For additional information, refer to «TRANSFER CASE SHIFT MOTOR»(/ford/explorer-sport-trac/i-2000-2005/remont/transfer-case/#transfer-case-automatic-shift) in TRANSFER CASE - AUTOMATIC SHIFT article.
6. To install, reverse the removal procedure. Apply a coat of Multi-Purpose Grease DOAZ-19584-AA or equivalent meeting Ford specification ESB-M1C93-B to the gearmotor encoder assembly.

Scheme 53

1. Remove the passenger cowl side trim panel.
2. Remove the four wheel drive (4WD) control module. Disengage the locking tangs and remove the harness connectors. Remove the screws. Remove the four wheel drive (4WD) control module.
3. To install, reverse the removal procedure.

See also:
• TRANSFER CASE - AUTOMATIC SHIFT
• MODULE COMMUNICATIONS NETWORK
• SYSTEM TESTS
• GAUGES & INSTRUMENT PANELS
• PINPOINT TEST B: NO COMMUNICATION WITH FOUR-WHEEL DRIVE (4WD) CONTROL MODULE
• PINPOINT TEST A: ELECTRONIC SHIFT FUNCTIONAL TEST