Transfer Case - Four Wheel Drive (4wd) Systems Ford Taurus X I

SPECIFICATIONS

TORQUE SPECIFICATIONS TABLE

TORQUE SPECIFICATIONS TABLE

The All-Wheel Drive (AWD) system consists of the following

1. Power Transfer Unit (PTU)
2. Rear driveshaft
3. 4X4 control module (coupling device control module) (located behind the RH side instrument panel)
4. Rear axle with coupling device

Torque from the engine is transferred through the transaxle to the PTU. This torque is transferred from the driveshaft to the rear axle, which drives the rear halfshafts. The AWD system, referred to as an Active Torque Coupling (ATC) system, is always active and requires no driver input.

The AWD system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. During normal operation, most of the torque is delivered to the front wheels. If wheel slip between the front and rear wheels is detected, or if the vehicle is under heavy acceleration, the AWD system increases torque to the rear wheels to prevent or control wheel slip.

Serviceable components of the PTU are limited to the output shaft seal and flange, intermediate shaft seal and deflector, and the PTU-transaxle compression seal. No internal components are serviced. There should be no need to remove the PTU cover. If any of the internal geared components, bearings, case cover or shafts are worn or damaged, a new PTU must be installed.

Special Tools Illustration Tool Name Tool Number 73III Automotive Meter 105-R0057 or equivalent Flex Probe Kit 105-R025C Vehicle Communication Module (VCM) and Integrated Diagnostic System (IDS) software with appropriate hardware, or equivalent scan tool

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Principles of Operation

The vehicle is equipped with an All-Wheel Drive (AWD) system, also referred to as Active Torque Coupling (ATC), that is always active and requires no driver input. The system has no Mode Select Switch (MSS).

The system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. During normal operation, most of the torque is sent to the front wheels. If wheel slip between the front and rear wheels is detected or if the vehicle is under heavy acceleration (high throttle position), the AWD system increases torque to the rear wheels to prevent or control wheel slip.

The system consists of a Power Transfer Unit (PTU), 4X4 control module, rear axle and a solenoid actuated ATC device. Based on the amount of current sent to the clutch, the module varies the torque sent to the rear wheels by sending a duty cycle to the ATC device, located inside the rear axle. For concerns with the PTU, refer to TRANSFER CASE - POWER TRANSFER UNIT (PTU) article.

The 4X4 control module also provides the brake system with its current clutch duty cycle and determines whether or not the brake system may take command of the clutch duty cycle.

Note. The ATC solenoid is not repairable. If a new component is required, the ATC solenoid and rear axle are installed as an assembly. Refer to REAR DRIVE AXLE/DIFFERENTIAL article.

The active, on-demand AWD system uses data from other systems as inputs to the 4X4 control module. The 4X4 control module uses the inputs to determine the appropriate amount of current to send to the ATC solenoid that delivers the desired torque to the rear wheels. Specific inputs to the 4X4 control module are

1. Accelerator pedal position via the High Speed Controller Area Network (HS-CAN)
2. Transaxle range from the Transmission Control Module (TCM) via the HS-CAN
3. Brake system status from the ABS module via the HS-CAN
4. Wheel speed from all 4 wheels from the ABS module via the HS-CAN

4X4 control module outputs are

1. Solid-state clutch (pulse-width modulated signal) to the ATC solenoid
2. Percent of torque transfer commanded signal to the ABS module via the HS-CAN
3. Torque request available signal to the ABS module via the HS-CAN

Heat Protection Mode - During very extreme off-road operation, the AWD system utilizes a heat protection mode to protect the ATC solenoid (part of rear axle) from damage. If the system detects an overheat condition, it enters a locked mode. If the heat in the system continues to rise once in the locked mode, the 4X4 control module disables the ATC solenoid. Allow the system to cool down at least 10 minutes with the ignition switch in the ON position.

Inspection and Verification

1. Verify the customer concern.
2. Inspect for obvious signs of mechanical or electrical damage. VISUAL INSPECTION CHART Mechanical Electrical Active Torque Coupling (ATC) solenoid (part of rear axle) Power Transfer Unit (PTU) Rear Drive Unit (RDU) Halfshafts and CV joints Driveshaft and U-joints Fluid leaks Wheel/tire size and brand Matching tire size and brand Tire pressure Voltage Regulator (VR) fuse(s): 11 (10A) 34 (5A) 4X4 control module Wiring harness Connector(s) Circuitry
3. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.
4. If the cause is not visually evident, connect the scan tool to the Data Link Connector (DLC).
5. If the scan tool does not communicate with the VCM: check the VCM connection to the vehicle. check the scan tool connection to the VCM. refer to «MODULE COMMUNICATIONS NETWORK»(/ford/taurus-x/i-2007-2009/remont/communication-devices/#module-communications-network-system) article, No Power To The Scan Tool, to diagnose no communication with the scan tool.
6. If the scan tool does not communicate with the vehicle: verify the ignition key is in the ON position. refer to «MODULE COMMUNICATIONS NETWORK»(/ford/taurus-x/i-2007-2009/remont/communication-devices/#module-communications-network-system) article to diagnose no response from the PCM.
7. Carry out the network test. If the scan tool responds with no communication for one or more modules, refer to «MODULE COMMUNICATIONS NETWORK»(/ford/taurus-x/i-2007-2009/remont/communication-devices/#module-communications-network-system) article. If the network test passes, retrieve and record continuous memory DTCs.
8. Clear the DTCs and carry out the self-test diagnostics for the 4X4 control module.
9. If the DTCs retrieved are related to the concern, go to the 4X4 Control Module DTC Table. For all other DTCs, refer to «MULTIFUNCTION ELECTRONIC MODULES»(/ford/taurus-x/i-2007-2009/remont/communication-devices/#multifunction-electronic-modules-system) article.
10. If no DTCs related to the concern are retrieved, go to «Symptom Chart - Four Wheel Drive System»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems) .

DTC Tables

4X4 CONTROL MODULE DTC TABLE

Symptom Chart - Four Wheel Drive System

Symptom Chart - Four Wheel Drive System

Pinpoint Test A: All-Wheel Drive (AWD) System Functional Test

Refer to appropriate SYSTEM WIRING DIAGRAMS article, All Wheel Drive (AWD) for schematic and connector information.

Normal Operation

The All-Wheel Drive (AWD) system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. During normal operation, most of the torque is delivered to the front wheels. If wheel slip between the front and rear wheels is detected, or if the vehicle is under heavy acceleration, the AWD system increases torque to the rear wheels to prevent or control wheel slip.

This pinpoint test is intended to diagnose the following

1. AWD system concern without on-demand or continuous DTCs

Note. Carry out a thorough inspection and verification as outlined before carrying out this pinpoint test. Refer to Inspection and Verification .

1. A1 CHECK FOR WRENCH LIGHT PROVE-OUT Turn the ignition to the ON position and observe the wrench light. Does the wrench light illuminate for 3 seconds and then turn OFF? YES : Go to A2 . NO : REFER to «INSTRUMENT CLUSTER (IC), MESSAGE CENTER, AND WARNING CHIMES»(/ford/taurus-x/i-2007-2009/remont/gauges-instrument-panels/#information-center) article for further diagnosis of the Instrument Cluster (IC).
2. A2 CHECK FOR Active Torque Coupling (ATC) SOLENOID (PART OF REAR AXLE) LOCK Drive the vehicle on a dry, hard surface in turns while applying the accelerator pedal. Is driveline wind-up present in turns? YES : With the ignition switch in ON position, allow the ATC solenoid to cool down for at least 10 minutes and repeat the test. CHECK for wind-up again. If no wind-up is found, Go to A3 . If still present, go to «Pinpoint Test F»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems) . NO : Go to A3 .
3. A3 CHECK FOR VALID ACCELERATOR PEDAL POSITION MONITORING THE ACCELERATOR PEDAL POSITION (AP) PID Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module Monitor the AP PID while pressing the accelerator pedal. Does the accelerator pedal position match the AP PID percent value? YES : Go to A4 . NO : REFER to the «Introduction - Gasoline Engines»(/ford/taurus-x/i-2007-2009/remont/testing-diagnostics/#engine-controls-introduction-except-diesel-hybrid) article to diagnose the accelerator pedal position sensor concern.
4. A4 CHECK 4X4 CONTROL MODULE WHEEL SPEED SENSOR PIDs Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module While driving the vehicle at 48 km/h (30 mph), monitor the following wheel speed sensor PIDs: Left Front Wheel Speed Sensor (LF_WSPD) Left Rear Wheel Speed Sensor (LR_WSPD) Right Front Wheel Speed Sensor (RF_WSPD) Right Rear Wheel Speed Sensor (RR_WSPD) Are all 4 wheel speeds within 2 km/h (1.2 mph) of each other? YES : Go to A5 . NO : Go to «Pinpoint Test F»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems__pinpoint-test-f-dtc-p1635) .
5. A5 CHECK VEHICLE ACCELERATION IN A STRAIGHT LINE Carry out 3 accelerations from 0-48 km/h (0-30 mph) in a straight line (one each with low, medium and full accelerator pedal application). Does the vehicle pulsate or shudder while accelerating? YES : Go to «Pinpoint Test F»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems__pinpoint-test-f-dtc-p1635) . NO : Go to A6 .
6. A6 CHECK VEHICLE TURNING ABILITY Drive the vehicle in a fully locked turn, on dry pavement, at 8 km/h (5 mph). Does the vehicle bind in the turn or resist turning? YES : Go to «Pinpoint Test F»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems__pinpoint-test-f-dtc-p1635) . NO : Go to A7 .
7. A7 CHECK FOR TORQUE AT REAR WHEELS USING PWM OUTPUT CONTROL COMMAND #1 (CLCH_SOL) ACTIVE COMMAND Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module Using the scan tool, command CLCH_ SOL to energize the ATC solenoid to a constant 100% applied. Drive the vehicle in a fully locked turn, on dry pavement, at 8 km/h (5 mph). Does the vehicle bind in the turn or resist turning? YES : END the active command. The concern can not be duplicated at this time. RETURN the vehicle to the customer. NO : END the active command. CHECK that the driveshaft rotates when the transaxle is in gear. If yes, go to «Pinpoint Test E»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems__pinpoint-test-e-vehicle-binds-in) . If no, CHECK the Power Transfer Unit (PTU). REFER to «TRANSFER CASE - POWER TRANSFER UNIT (PTU)»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-power-transfer-unit-ptu) article.

Pinpoint Test B: DTC B1317/B1318 - Battery Voltage is High/Low (4X4 Control Module)

Refer to appropriate SYSTEM WIRING DIAGRAMS article, All Wheel Drive (AWD) for schematic and connector information.

If the 4X4 control module observes an overpower or underpower voltage condition, DTCs are set and the 4X4 control module may not allow Four-Wheel Drive (4WD) operation.

1. DTC B1317 Battery Voltage High - When the 4X4 control module detects battery voltage greater than 16 volts for at least 10 seconds, DTC B1317 is set.
2. DTC B1318 Battery Voltage Low - When the 4X4 control module detects battery voltage less than 9 volts for at least 10 seconds, with the engine running at 1,500 RPM or greater, DTC B1318 is set.

This pinpoint test is intended to diagnose the following

1. Fuses
2. Wiring, terminals or connectors
3. 4X4 control module

Note. DTCs B1317, B1318 or B1676 can be set if the vehicle has been recently jump started, the battery has been recently charged or the battery has been discharged. The battery may become discharged due to excessive load(s) on the charging system from aftermarket accessories or if the vehicle has been left unattended with the accessories on.

Note. Carry out a thorough inspection and verification before proceeding with the pinpoint test. Refer to Inspection and Verification .

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1. B1 RETRIEVE ALL CONTINUOUS MEMORY DTCs Continuous Memory Diagnostic Trouble Codes (CMDTCs) IN ALL MODULES Enter the following diagnostic mode on the diagnostic tool: Self Test - All CMDTCs Is B1317, B1318 or B1676 present in more than one module AND P0563, P0620, P0625, P0626 or P065B present in the PCM? YES : REFER to «CHARGING SYSTEM - GENERAL INFORMATION»(/ford/taurus-x/i-2007-2009/remont/charging-system/#charging-system-general-information) article for diagnosis of the battery and charging system. NO : Go to B2 .
2. B2 CHECK BATTERY CONDITION Refer to «BATTERY, MOUNTING AND CABLES»(/ford/taurus-x/i-2007-2009/remont/body-electrical/#battery-mounting-and-cables) article and carry out the Battery - Condition Test. Does the battery pass the condition test? YES : If the battery passed the condition test but required a recharge, REFER to «CHARGING SYSTEM - GENERAL INFORMATION»(/ford/taurus-x/i-2007-2009/remont/charging-system/#charging-system-general-information) article to diagnose the charging system. CLEAR all continuous memory DTCs. TEST the system for normal operation. If the battery passed the condition test and did not require a recharge, go to B3 . NO : INSTALL a new battery. CLEAR all continuous memory DTCs. TEST the system for normal operation.
3. B3 CHECK THE CHARGING SYSTEM VOLTAGE NOTE: Do not allow the engine RPM to increase above 2,000 RPM while performing this step or the generator may self excite and result in default charging system output voltage. If engine RPM has gone above 2,000 RPM, shut the vehicle off and restart the engine before performing this step. Start the engine. Measure the voltage of the battery. For DTC B1317, turn off all accessories and run the engine at 1,500 RPM for a minimum of 2 minutes. For DTC B1318, turn on headlights and HVAC fan on high and run engine at 1,500 RPM for a minimum of 2 minutes. Is the battery voltage between 13-15.2 volts? YES : Go to B4 . NO : REFER to «CHARGING SYSTEM - GENERAL INFORMATION»(/ford/taurus-x/i-2007-2009/remont/charging-system/#charging-system-general-information) article to diagnose the charging system. CLEAR all continuous memory DTCs. TEST the system for normal operation.
4. B4 CHECK FOR VOLTAGE BY MONITORING THE MODULE SUPPLY VOLTAGE (VBAT_4X4) PID Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module With the engine running, monitor the battery voltage VBAT_4X4 PID. Is the battery voltage less than 9 or greater than 15.5 volts? YES : If voltage is less than 9 volts, go to B5 . If voltage is greater than 15.5 volts, INSTALL a new 4X4 control module. REFER to «4X4 Control Module»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems) . CLEAR all continuous memory DTCs. REPEAT the self-test. NO : Go to B7 .
5. B5 CHECK CIRCUIT GD148 (BK/WH) FOR AN OPEN Key in OFF position. Disconnect: 4X4 Control Module C281 Measure the resistance between 4X4 control module C281-15, circuit GD148 (BK/YE), harness side and ground. Repeat this measurement while wiggling the harness. Is the resistance less than 5 ohms? YES : Go to B6 . NO : REPAIR the circuit. CLEAR all continuous memory DTCs. REPEAT the self-test.
6. B6 CHECK POWER TO 4X4 CONTROL MODULE Key in ON position. Measure the voltage between 4X4 control module C281-5, circuit SBP11 (BU/RD), harness side and ground; and between 4X4 control module C281-4, circuit CBP34 (VT/BN), harness side and ground. Is the voltage greater than 10 volts? YES : Go to B7 . NO : VERIFY Smart Junction Box (SJB) fuse(s) 11 (10A) and 34 (5A) are OK. If fuse(s) are OK, REPAIR the circuit in question. If SJB fuse(s) are not OK, REFER to the Wiring Diagram Manual to identify possible causes of the circuit short. CLEAR all continuous memory DTCs. REPEAT the self-test.
7. B7 CHECK FOR CORRECT 4X4 CONTROL MODULE OPERATION Disconnect the 4X4 control module. Check the harness and component side connectors for: corrosion. pushed-out/bent pins. Connect the 4X4 control module and make sure it seats correctly. Operate the system and determine if the concern is still present. Is the concern still present? YES : INSTALL a new 4X4 control module. REFER to «4X4 Control Module»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems) . CLEAR the continuous memory DTCs. REPEAT the self-test. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR all continuous memory DTCs. REPEAT the self-test.

Pinpoint Test C: DTC U0415 - 4X4 Control Module Received No/Invalid Data From ABS Module

Refer to appropriate SYSTEM WIRING DIAGRAMS article, All Wheel Drive (AWD) for schematic and connector information.

The All-Wheel Drive (AWD) system uses data from other systems as inputs to the 4X4 control module. The 4X4 control module uses the inputs to determine the appropriate duty cycle to send to the Active Torque Coupling (ATC) solenoid (part of rear axle) that delivers the desired torque to the rear wheels. Specific inputs to the 4X4 control module are: accelerator pedal position output from the PCM, brake system status and all 4 wheel speeds from the ABS module. Communication between the 4X4 control module and other modules is obtained through the High Speed Controller Area Network (HS-CAN). If the 4X4 control module loses communication with, or receives invalid data from any of the necessary modules, DTCs are set and the 4X4 control module may not allow Four-Wheel Drive (4WD) operation.

1. DTC U0415 Invalid Data Received from Anti-lock Brake System (ABS) Control Module - When the 4X4 control module receives invalid HS-CAN bus data or invalid wheel speed(s) from the ABS module for more than 5 seconds, this DTC is set.

This pinpoint test is intended to diagnose the following

1. ABS module

Note. Carry out a thorough inspection and verification as outlined before carrying out this pinpoint test. Refer to Inspection and Verification .

1. C1 CHECK FOR ABS MODULE DTCs Key in ON position. Carry out the ABS module self-test. Review the results of the ABS module self-test. Are any DTCs present? YES : REFER to «VEHICLE DYNAMIC SYSTEMS»(/ford/taurus-x/i-2007-2009/remont/anti-locktraction-control/#anti-lock-brake-system) article for further diagnosis of the ABS. NO : Go to C2 .
2. C2 CHECK WHEEL SPEED SENSORS PIDs Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module While driving the vehicle at 48 km/h (30 mph), monitor the following wheel speed sensor PIDs: Left Front Wheel Speed Sensor (LF_WSPD) Left Rear Wheel Speed Sensor (LR_WSPD) Right Front Wheel Speed Sensor (RF_WSPD) Right Rear Wheel Speed Sensor (RR_WSPD) Do the 4 wheel speed sensors match the speedometer and are they within 2 km/h (1.2 mph) of each other? YES : The system is operating correctly at this time. CLEAR the DTCs. REPEAT the self-test. NO : INSPECT for proper tire size and tire inflation. If no concerns with the tires are found, REFER to «VEHICLE DYNAMIC SYSTEMS»(/ford/taurus-x/i-2007-2009/remont/anti-locktraction-control/#anti-lock-brake-system) article for further diagnosis of the ABS.

Pinpoint Test D: DTCs P1824/P1825 - 4-Wheel Drive Clutch Relay Circuit Failure/4-Wheel Drive Clutch Relay Open Circuit

Refer to appropriate SYSTEM WIRING DIAGRAMS article, All Wheel Drive (AWD) for schematic and connector information.

The All-Wheel Drive (AWD) system uses data from other systems as inputs to the 4X4 control module. The 4X4 control module uses the inputs to determine the appropriate duty cycle to send to the Active Torque Coupling (ATC) solenoid (part of rear axle) that delivers the desired torque to the rear wheels. If the 4X4 control module loses communication with, or receives invalid data from any of the necessary modules, DTCs are set and the 4X4 control module may not allow 4WD operation.

1. DTC P1824 4-Wheel Drive Clutch Relay Circuit Failure - When the 4X4 control module detects a short to ground on the ATC solenoid feedback circuit, this DTC is set.
2. DTC P1825 4-Wheel Drive Clutch Relay Open Circuit - When the 4X4 control module detects an open or short to ground on the ATC solenoid command or feedback circuit for more than 2 seconds, this DTC is set.

This pinpoint test is intended to diagnose the following

1. Tire/axle out of range
2. ATC solenoid (part of rear axle)
3. 4X4 control module
4. Power Transfer Unit (PTU)
5. Wiring, terminals or connectors

Note. Carry out a thorough inspection and verification as outlined before carrying out this pinpoint test. Refer to Inspection and Verification .

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1. D1 CHECK FOR 4X4 CONTROL MODULE DTCs Key in ON position. Carry out the 4X4 control module self-test. Are any DTCs received? YES : For DTC P1824 or P1825, go to D2 . For all other DTCs, REFER to the «4X4 CONTROL MODULE DTC TABLE»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems) . NO : Go to D2 .
2. D2 CHECK CIRCUITS CCF21 (VT/WH) AND RCF21 (WH/VT) FOR A SHORT TO GROUND WITH ATC SOLENOID (PART OF REAR AXLE) CONNECTED Key in OFF position. Disconnect: 4X4 Control Module C281 Measure the resistance between 4X4 control module C281-8, circuit CCF21 (VT/WH), harness side and ground; and between 4X4 control module C281-16, circuit RCF21 (WH/VT), harness side and ground. Are the resistances greater than 10,000 ohms? YES : Go to D5 . NO : Go to D3 .
3. D3 CHECK CIRCUITS CCF21 (VT/WH) AND RCF21 (WH/VT) FOR A SHORT TO GROUND WITH C314 DISCONNECTED Disconnect: ATC Solenoid Jumper Harness C314 Measure the resistance between 4X4 control module C281-8, circuit CCF21 (VT/WH), harness side and ground; and between 4X4 control module C281-16, circuit RCF21 (WH/VT), harness side and ground. Are the resistances greater than 10,000 ohms? YES : Go to D4 . NO : REPAIR the circuit(s) in question. CLEAR the DTCs. REPEAT the self-test.
4. D4 CHECKING THE ATC SOLENOID JUMPER HARNESS NOTE: The ATC solenoid jumper harness must be secured to prevent damage to the wiring. Disconnect: ATC Solenoid C4347 Inspect the ATC solenoid jumper harness for damage. Is the ATC solenoid jumper harness damaged? YES : REPAIR or INSTALL a new ATC solenoid jumper harness. CLEAR the DTCs. REPEAT the self-test. NO : INSTALL a new rear axle assembly. REFER to «REAR DRIVE AXLE/DIFFERENTIAL»(/ford/taurus-x/i-2007-2009/remont/differentials-drive-axles/#rear-drive-axledifferential) article. CLEAR the DTCs. REPEAT the self-test.
5. D5 CHECK CIRCUITS CCF21 (VT/WH) AND RCF21 (WH/VT) FOR AN OPEN WITH ATC SOLENOID CONNECTED Connect: ATC Solenoid C4347 and ATC Solenoid Jumper Harness C314 Measure the resistance between 4X4 control module C281-8, circuit CCF21 (VT/WH), harness side and 4X4 control module C281-16, circuit RCF21 (WH/VT), harness side. Is the resistance less than 10 ohms? YES : Go to D8 . NO : Go to D6 .
6. D6 CHECK CIRCUITS CCF21 (VT/WH) AND RCF21 (WH/VT) FOR AN OPEN AT C314 Disconnect: ATC Solenoid Jumper Harness C314 Measure the resistance between 4X4 control module C281-8, circuit CCF21 (VT/WH), harness side and ATC solenoid jumper harness C314-1, circuit CCF21 (VT/WH). Repeat this measurement while wiggling the harness. Measure the resistance between 4X4 control module C281-16, circuit RCF21 (WH/VT), harness side and ATC solenoid jumper harness C314-2, circuit RCF21 (WH/VT), harness side. Repeat this measurement while wiggling the harness. Are the resistances less than 5 ohms? YES : Go to D7 . NO : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
7. D7 CHECK THE ATC SOLENOID CIRCUIT FOR AN INTERNAL OPEN NOTE: The Active Torque Coupling (ATC) solenoid jumper harness must be secured to prevent damage to the wiring. Disconnect: ATC Solenoid C4347 Measure the resistance between ATC solenoid C4347-1, circuit CCF21 (VT/WH), component side, and ATC solenoid C4347-2, circuit RCF21 (WH/VT), component side. Repeat this measurement while wiggling the harness. Is the resistance less than 10 ohms? YES : REPAIR or INSTALL a new ATC solenoid jumper harness. CLEAR the DTCs. REPEAT the self-test. NO : INSTALL a new rear axle assembly. REFER to «REAR DRIVE AXLE/DIFFERENTIAL»(/ford/taurus-x/i-2007-2009/remont/differentials-drive-axles/#rear-drive-axledifferential) article. CLEAR the DTCs. REPEAT the self-test.
8. D8 CHECK CIRCUIT GD148 (BK/YE) FOR AN OPEN Measure the resistance between 4X4 control module C3253-15, circuit GD148 (BK/YE), harness side and ground. Repeat this measurement while wiggling the harness. Is the resistance less than 5 ohms? YES : Go to D9 . NO : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
9. D9 CHECK THE 4X4 CONTROL MODULE POWER CIRCUITS Key in ON position. Measure the voltage between 4X4 control module C281-5, circuit SBP11 (BU/RD), harness side and ground; and between 4X4 control module C281-4, circuit CBP34 (VT/BN), harness side and ground. Are the voltages greater than 10 volts? YES : Go to D10 . NO : CHECK Smart Junction Box (SJB) fuses 11 (10A) and 34 (5A). REPAIR the circuit in question for open or short to ground. CLEAR the DTCs. REPEAT the self-test.
10. D10 CHECK FOR CORRECT 4X4 CONTROL MODULE OPERATION Disconnect: 4X4 Control Module C281 Check the harness and component side connectors for: corrosion. pushed-out/bent pins. Check the ATC solenoid jumper harness between the 4X4 control module and the ATC solenoid, located on the rear subframe. Connect the 4X4 control module and make sure it seats correctly. Operate the system and determine if the concern is still present. Is the concern still present? YES : INSTALL a new 4X4 control module. REFER to «4X4 Control Module»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems) . CLEAR the DTCs. REPEAT the self-test. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

Pinpoint Test E: Vehicle Binds in a Turn or Resists Turning/Pulsates or Shudders in a Straight Line

Refer to appropriate SYSTEM WIRING DIAGRAMS article, All Wheel Drive (AWD) for schematic and connector information.

The All-Wheel Drive (AWD) system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. During normal operation, most of the torque is sent to the front wheels. If wheel slip between the front and rear wheels is detected or the vehicle is under heavy acceleration, the AWD system increases torque to the rear wheels.

This pinpoint test is intended to diagnose the following

1. Rear axle
2. Wheels/tires
3. PCM
4. ABS module
5. 4X4 control module
6. Circuitry

Note. Carry out a thorough inspection and verification as outlined before carrying out this pinpoint test. Refer to Inspection and Verification .

1. E1 CHECK FOR TORQUE AT THE REAR WHEELS Key in OFF position. Disconnect: Active Torque Coupling (ATC) Solenoid (part of rear axle) C4347 Drive the vehicle in a straight line on dry pavement. Is a pulsation or shudder still present? YES : REFER to «DRIVELINE SYSTEM - GENERAL INFORMATION»(/ford/taurus-x/i-2007-2009/remont/axle-shafts/#driveline-system-general-information) article for additional axle diagnosis. NO : Go to E2 .
2. E2 CHECK TO SEE IF ATC SOLENOID IS BEING COMMANDED ON MONITORING 4WD CLUTCH PWM STATUS (4WDCPWMST) PID Key in OFF position. Connect: ATC Solenoid C4347 Key in ON position. Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module Monitor the 4WDCPWMST PID. Drive the vehicle no faster than 8 km/h (5 mph) in tight turns on dry pavement while monitoring the ATC solenoid duty cycle. Is the duty cycle greater than 20%? YES : Go to E3 . NO : Go to «Pinpoint Test F»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems__pinpoint-test-f-dtc-p1635) .
3. E3 CHECK FOR THE CORRECT WHEEL SPEEDS USING THE WHEEL SPEED SENSORS PIDs Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module While driving the vehicle at 48 km/h (30 mph), monitor the following wheel speed sensor PIDs: Left Front Wheel Speed Sensor (LF_WSPD) Left Rear Wheel Speed Sensor (LR_WSPD) Right Front Wheel Speed Sensor (RF_WSPD) Right Rear Wheel Speed Sensor (RR_WSPD) Are all 4 wheel speeds within 2 km/h (1.2 mph) of each other? YES : Go to E4 . NO : Go to «Pinpoint Test F»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems__pinpoint-test-f-dtc-p1635) .
4. E4 CHECK FOR VALID ACCELERATOR PEDAL POSITION MONITORING ACCELERATOR PEDAL POSITION (AP) PID Key ON Engine OFF (KOEO). Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module Monitor AP PID while pressing/releasing the accelerator pedal. Does the accelerator position match the PID percent value? YES : Go to E5 . NO : REFER to the «Introduction - Gasoline Engines»(/ford/taurus-x/i-2007-2009/remont/testing-diagnostics/#engine-controls-introduction-except-diesel-hybrid) article to diagnose the engine control system.
5. E5 CHECK FOR CORRECT 4X4 CONTROL MODULE OPERATION Disconnect the 4X4 control module. Check the harness and component side connectors for: corrosion. pushed-out/bent pins. Check the ATC solenoid jumper harness between the 4X4 control module and the ATC solenoid, located on the rear subframe. Connect the 4X4 control module and make sure it seats correctly. Operate the system and determine if the concern is still present. Is the concern still present? YES : INSTALL a new 4X4 control module. REFER to «4X4 Control Module»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems) . CLEAR the DTCs. REPEAT the self-test. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

Pinpoint Test F: DTC P1635 - Tire/Axle Out of Acceptable Range

Refer to appropriate SYSTEM WIRING DIAGRAMS article, All Wheel Drive (AWD) for schematic and connector information.

The All-Wheel Drive (AWD) system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. During normal operation, most of the torque is sent to the front wheels. If wheel slip between the front and rear wheels is detected or the vehicle is under heavy acceleration, the AWD system increases torque to the rear wheels.

1. DTC P1635 Tire/Axle Out of Acceptable Range - When the 4X4 control module detects inappropriate mini spare or road wheels/tires (greater than 7% across the front and rear axle or 14% at one wheel) installed, this DTC is set.

This pinpoint test is intended to diagnose the following

1. Wheels/tires
2. Wheel speed sensors
3. ABS module
4. 4X4 control module

Note. Carry out a thorough inspection and verification as outlined before carrying out this pinpoint test. Refer to Inspection and Verification .

1. F1 CHECK THE RECENT TIRE USAGE Check with customer about recent tire usage or installation. Has a tire been installed on the vehicle recently that was not originally supplied with the vehicle? YES : INFORM the customer to only use tires of the type supplied with the vehicle. CLEAR the DTCs. REPEAT the self-test. NO : Go to F2 .
2. F2 CHECK TIRE SIZE AND BRAND Check the tire size and the brand of tire. Are all 4 tires the same size and brand? YES : Go to F3 . NO : INSTALL tires that are the same size and brand. INFORM the customer to only use the same size tires and brand. CLEAR the DTCs. REPEAT the self-test.
3. F3 CHECK TIRE AIR PRESSURES Check the air pressure in all 4 tires. Are all 4 tires at the recommended air pressure? YES : Go to F4 . NO : ADJUST the tire air pressures. CLEAR the DTCs. REPEAT the self-test. INFORM the customer to maintain the correct tire air pressure.
4. F4 CHECK FOR CORRECT WHEEL SPEEDS Connect the diagnostic tool. Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module While driving the vehicle at 48 km/h (30 mph), monitor the following wheel speed sensor PIDs: Left Front Wheel Speed Sensor (LF_WSPD) Left Rear Wheel Speed Sensor (LR_WSPD) Right Front Wheel Speed Sensor (RF_WSPD) Right Rear Wheel Speed Sensor (RR_WSPD) Are all 4 wheel speeds within 2 km/h (1.2 mph) of each other? YES : Go to F5 . NO : The ABS module is sending invalid wheel speed data to the 4X4 control module. REFER to «VEHICLE DYNAMIC SYSTEMS»(/ford/taurus-x/i-2007-2009/remont/anti-locktraction-control/#anti-lock-brake-system) article for additional ABS diagnosis.
5. F5 CHECK FOR CORRECT 4X4 CONTROL MODULE OPERATION Disconnect: 4X4 Control Module C281 Check for: corrosion. pushed-out pins. Connect the 4X4 control module and make sure it seats correctly. Operate the system and determine if the concern is still present. Is the concern still present? YES : INSTALL a new 4X4 control module. REFER to «4X4 Control Module»(/ford/taurus-x/i-2007-2009/remont/transfer-case/#transfer-case-four-wheel-drive-4wd-systems) . CLEAR the DTCs. REPEAT the self-test. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.

REMOVAL AND INSTALLATION

1. Working in the passenger compartment, pull the carpet out-of-the way, then disconnect the 4X4 control module electrical connector.
2. Disconnect the glove compartment rod. Rotate the glove compartment downward.
3. Carefully pry the 4X4 control module and bracket assembly from the holding bracket.
4. Remove the 4X4 control module and bracket assembly from the vehicle.
5. To install, reverse the removal procedure.

See also:
• TRANSFER CASE - POWER TRANSFER UNIT (PTU)
• REAR DRIVE AXLE/DIFFERENTIAL
• MODULE COMMUNICATIONS NETWORK
• MULTIFUNCTION ELECTRONIC MODULES
• MODULE CONFIGURATION
• Introduction - Gasoline Engines
• WHEELS AND TIRES
• BRAKE SYSTEM - GENERAL INFORMATION
• SUSPENSION SYSTEM - GENERAL INFORMATION
• DRIVELINE SYSTEM - GENERAL INFORMATION
• VEHICLE DYNAMIC SYSTEMS
• INSTRUMENT CLUSTER (IC), MESSAGE CENTER, AND WARNING CHIMES
• CHARGING SYSTEM - GENERAL INFORMATION
• BATTERY, MOUNTING AND CABLES
• Symptom Chart - Four Wheel Drive System
• Pinpoint Test B
• Pinpoint Test F
• Pinpoint Test D
• Pinpoint Test C
• Pinpoint Test A
• Pinpoint Test E
• Inspection and Verification