All Wheel Drive Systems. Diagnosis and Testing

DTC Chart: All Wheel Drive System - PCM

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

Network Dtcs (U-codes) are often the result of intermittent concerns such as damaged wiring or low battery voltage. In addition, vehicle repair procedures such as module reprogramming often set network DTCs. Replacing a module to fix a network DTC is unlikely to solve the concern. To prevent recurrence of network DTC concerns, inspect all network wiring, especially the connectors. Check the vehicle battery.
Refer to: Battery (414-01 Battery, Mounting and Cables, Diagnosis and Testing).

PCM DTC Chart

Trouble Code	Description	Action
P164D	AWD ID block is damaged or not programmed	PROGRAM the PCM with the Active Torque Coupling (ATC) solenoid barcode information using the Torque Coupling automatic configuration. Refer to: All Wheel Drive Systems - System Operation and Component Description (308-07A All Wheel Drive Systems, Description and Operation).
P181F	Clutch Control System Performance	This is an internal fault of the AWD relay module. INSTALL a new AWD relay module. Refer to: All Wheel Drive (AWD) Module (308-07A All Wheel Drive Systems, Removal and Installation).
P182B	Transfer Case Fluid Temperature Sensor Circuit Range/Performance	GO to Pinpoint Test F
P182C	Transfer Case Fluid Temperature Sensor Circuit Low	GO to Pinpoint Test F
P182D	Transfer Case Fluid Temperature Sensor Circuit High Signal Level	GO to Pinpoint Test F
P183D	Transfer Case Fluid Overtemperature	GO to Pinpoint Test F
P187B	Tire Size Out of Range - All Wheel Drive Disabled / Limited Function	GO to Pinpoint Test B
P188B	All Wheel Drive Clutch Control Circuit	GO to Pinpoint Test C
P188C	All Wheel Drive Relay Module Communication Circuit	CLEAR the DTCs. REPEAT the self-test. If the DTC returns, GO to Pinpoint Test D.
P188D	All Wheel Drive Relay Module Feedback Circuit	CLEAR the DTCs. REPEAT the self-test. If the DTC returns, GO to Pinpoint Test D.

Symptom Chart

The diagnosis in this manual assumes a certain level of skill and knowledge of Ford-approved diagnostic procedures.
REFER TO: Diagnostic Methods (100-00 General Information, Description and Operation).

In most cases, the PCM sets DTCs to aid in diagnosis. Refer to the DTC Chart before using the symptom chart. The Symptom column lists the vehicle condition. The Possible Sources column lists the specific vehicle condition details. The Action column lists the actions to perform to determine the cause of the condition. Each action lists the components that may cause the system fault and individual components of that system. Components are listed in disassembly order. Use the component list and required actions to focus on disassembly checks for the root cause of the concern.

Symptom Chart - All Wheel Drive Systems

Condition	Possible Sources	Action
Unable to duplicate customer concern; no DTCs present	Concern description is inaccurate	PERFORM the All Wheel Drive system functional test. GO to Pinpoint Test A
Vehicle has no or insufficient torque at the rear wheels	Fuse Wiring, Terminals or Connectors Active Torque Coupling (ATC) solenoid All-wheel drive relay module PCM	GO to Pinpoint Test C
	Wheels/Tires	Inspect the wheels and tires for damage. Refer to: Wheels and Tires (204-04A Wheels and Tires, Diagnosis and Testing).
	Rear Axle	Inspect the rear axle for damage. Refer to: Rear Axle and Differential (205-02 Rear Axle/Differential, Diagnosis and Testing).
	PTU mechanical fault	Inspect the PTU for damage. Refer to: Rear Axle and Differential (205-02 Rear Axle/Differential, Diagnosis and Testing).
Vehicle binds in turns or resists turning/shudders or jerks in a straight line	Wheels/Tires	Inspect the wheels and tires for damage. Refer to: Wheels and Tires (204-04A Wheels and Tires, Diagnosis and Testing).
	Wiring, Terminals or Connectors	GO to Pinpoint Test E
	Driveshaft	Inspect the propshaft for damage. Refer to: Propshaft (205-01 Propshaft, Diagnosis and Testing).
	Wiring, Terminals or Connectors Active Torque Coupling (ATC) solenoid All-wheel drive relay module	GO to Pinpoint Test E
	PTU mechanical fault	Inspect the PTU for damage. Refer to: Power Transfer Unit (308-07B Power Transfer Unit - 6-Speed Automatic Transmission - 6F35, Diagnosis and Testing). Refer to: Power Transfer Unit (308-07C Power Transfer Unit - 6-Speed Automatic Transmission - 6F50/6F55, Diagnosis and Testing).
	Driveshaft	Inspect the propshaft for damage. Refer to: Suspension System (204-00 Suspension System - General Information, Diagnosis and Testing).
	Wheel bearings	Inspect the wheel bearings for damage. Refer to: Suspension System (204-00 Suspension System - General Information, Diagnosis and Testing).
	ABS	INSPECT the ABS. Refer to: Anti-Lock Brake System (ABS) and Stability Control System (206-09 Anti-Lock Brake System (ABS) and Stability Control System, Diagnosis and Testing).
	Half Shafts	Inspect the half shafts for damage. Refer to: Rear Drive Half Shafts (205-05 Rear Drive Half Shafts, Diagnosis and Testing).
Tire/axle out of tolerance	Wheels/Tires	GO to Pinpoint Test B

Pinpoint Tests

All Wheel Drive System Functional Test

Normal Operation and Fault Symptoms

The all-wheel drive system is an active system, which means that it not only reacts to wheel slip between the front and rear axles, but also has the ability to anticipate wheel slip and transfer torque to the rear wheels before slipping occurs. The all-wheel drive system is active at all times and does not require operator input. The all-wheel drive system constantly monitors vehicle conditions and automatically adjusts torque distribution between the front and rear wheels. During normal operation, most of the torque is delivered to the front wheels. If wheel slip is detected between the front and rear wheels, if the vehicle is accelerating, or if the vehicle is being steered, the all-wheel drive system increases and distributes torque to the rear wheels as needed. When the all-wheel drive system is operating normally, there should be no noticeable speed difference between the front and rear axles when starting or driving the vehicle on any level surface. Traction should be similar to a part-time 4WD system in 4H (4X4 HIGH), but without binding in turns .

AWD_CLTCH_CMD PID percentage displayed on the scan tool is an inverse value. 95% = clutch released, 5% = clutch fully engaged.

Visual Inspection and Preliminary Diagnosis

• ABS Sensor Wiring
• Constant Velocity (CV) Joints
• Driveshaft
• Half Shafts
• Tire Size
• Tire Wear
• U-Joints

PINPOINT TEST A: AWD (ALL WHEEL DRIVE) SYSTEM FUNCTIONAL TEST

WARNING: When this test calls for driving the vehicle, drive the vehicle on a firm surface in an area free of traffic to prevent an accident. Failure to follow these instructions may result in personal injury.

NOTE: Check the applicable modules for diagnostic trouble codes (DTCs). If DTCs are set in other modules, diagnose these DTCs before continuing.

A1 CHECK THE ACTIVE TORQUE COUPLING ELECTROMAGNETIC CLUTCH

Drive the vehicle on a dry, firm surface while applying the accelerator pedal. Is there transmission binding in turns? Yes GO to Pinpoint Test E No GO to A2

A2 CHECK THE ABS WHEEL SPEED

Using a scan tool, drive the vehicle at 30 mph (48 km/h) and 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 1.2 mph (2 km/h) of each other? Yes GO to A3 No REFER TO: Anti-Lock Brake System (ABS) and Stability Control System (206-09 Anti-Lock Brake System (ABS) and Stability Control System, Diagnosis and Testing).

A3 CHECK VEHICLE ACCELERATION IN A STRAIGHT LINE

Perform 3 accelerations from 0 mph (0 km/h) to 30 mph (48 km/h) in a straight line (one each with light, medium, and full accelerator pedal application). Does the vehicle pulsate or jerk during acceleration? Yes GO to Pinpoint Test E No GO to A4

A4 CHECK VEHICLE TURNING ABILITY

Drive the vehicle in a fully locked turn, on dry asphalt, at 5 mph (8 km/h). Does the vehicle bind or resist turning? Yes GO to Pinpoint Test E No GO to A5

A5 CHECK REAR WHEEL TORQUE

Using the diagnostic scan tool, apply a constant 10% duty cycle to the active torque coupling (ATC) solenoid. On dry asphalt, drive the vehicle in a fully locked turn at 5 mph (8 km/h). Does the vehicle bind or resist turning? Yes EXIT the active command. CLEAR all DTCs, if set. End of the system functional test. The system is currently operating correctly. No CHECK the power transfer unit (PTU). REFER TO: Power Transfer Unit (308-07B Power Transfer Unit - 6-Speed Automatic Transmission - 6F35, Diagnosis and Testing). REFER TO: Power Transfer Unit (308-07C Power Transfer Unit - 6-Speed Automatic Transmission - 6F50/6F55, Diagnosis and Testing).

DTC P187B

Normal Operation and Fault Symptoms

The all-wheel drive system uses input from the ABS module wheel speed sensors as an input to the PCM. A spare tire of a different size (other than the provided spare tire), or large unequal tire sizes or incorrectly inflated tires between the front and rear axles may cause the all-wheel drive system to not function properly.

DTC Fault Trigger Conditions

Trouble Code	Description	Fault Trigger Conditions
P187B	Tire Size Out of Acceptable Range - All-Wheel Drive Disabled/Limited Function	When the PCM detects tires/wheels of improper size (more than 5% difference in size between the front and rear axles, or more than 14% difference in size on one wheel on the front or rear axle).

Possible Causes

• Wiring, Terminals or Connectors
• Wheels/Tires
• ABS system

Visual Inspection and Preliminary Diagnosis

• Check the tire size and inflation.

PINPOINT TEST B: DTC P187B

B1 CHECK FOR RECENT USE OF DIFFERENT SIZE TIRES

Ask the customer about recent tire replacements or installations. Was a tire recently installed on the vehicle that did not originally come with the vehicle, or was a temporary spare tire used? Yes The concern may have been caused by previously mismatched tires. ENSURE that the tires do not exceed original equipment manufacturer (OEM) sizes and that all 4 tires are the same size. No GO to B2

B2 CHECK TIRE SIZE AND BRAND

Check the tire size and brand. Are all 4 tires the same size and brand? Yes GO to B3 No The tire size must not exceed original equipment manufacturer (OEM) recommendations, and all 4 tires must be the same size and brand. INSTALL new tire(s) as necessary.

B3 CHECK TIRE AIR PRESSURE

Check the air pressure in all 4 tires. Is the air pressure in all 4 tires within specification? Yes GO to B4 No ADJUST the tire air pressure to specification.

B4 CHECK ABS WHEEL SPEED

Drive the vehicle at 30 mph (48 km/h) and 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 1.2 mph (2 km/h) of each other? Yes GO to B5 No The ABS module is sending incorrect wheel speed data to the PCM. REFER TO: Anti-Lock Brake System (ABS) and Stability Control System (206-09 Anti-Lock Brake System (ABS) and Stability Control System, Diagnosis and Testing).

B5 CHECK ABS AND AWD (ALL-WHEEL DRIVE) SYSTEM OPERATION

Ignition OFF. Disconnect the ABS, all-wheel drive relay module and active torque coupling (ATC) solenoid connectors. Check the following: corrosion (install new connector or terminals - clean module pins) damaged or bent pins - install new terminals/pins backed-out pins - install new pins as necessary Reconnect the ABS, all-wheel drive relay module and active torque coupling (ATC) solenoid connectors. Make sure they are fully seated and locked. Operate the system and determine if the concern is still present. Is the concern still present? Yes CHECK OASIS for applicable TSBs. If a TSB exists for this concern, STOP this test and FOLLOW the TSB instructions. If no TSB resolves this concern, Click here to access the Managed Routine (ABS). Internet Explorer version 11 or later is required to perform this Pinpoint test. No The system is currently operating correctly. The concern may have been caused by module connections. Refer to the root cause of any connector or terminal issues.

DTC P188B

For wiring diagrams and connector information, refer to Section 34 of the wiring diagrams.

Normal Operation and Fault Symptoms

The all-wheel drive system uses data from other systems as inputs to the PCM. The PCM uses these inputs to determine the appropriate time to send a signal and energize the all-wheel drive relay module to the active torque coupling (ATC) solenoid.

AWD_CLTCH_CMD PID percentage displayed on the scan tool is an inverse value. 95% = clutch released, 5% = clutch fully engaged.

DTC Fault Trigger Conditions

Trouble Code	Description	Fault Trigger Conditions
P188B	All Wheel Drive Clutch Control Circuit	When the PCM detects an open circuit, a short to ground or a voltage in the active torque coupling (ATC) solenoid supply and/or return circuit.

Possible Causes

• Wiring, Terminals or Connectors
• Active torque coupling (ATC) solenoid (part of the rear drive unit (RDU))
• All-wheel drive relay module
• PCM

Visual Inspection and Preliminary Diagnosis

• Active torque coupling (ATC) solenoid harness

PINPOINT TEST C: P188B

C1 CHECK THE ACTIVE TORQUE COUPLING SOLENOID

Ignition OFF. Disconnect the active torque coupling (ATC) solenoid C4347. Action: Positive lead Measurement/Action Negative lead C4347-1 C4347-2 Is the resistance between 1 and 3 ohms? Yes GO to C2 No INSTALL a new active torque coupling. REFER TO: Active Torque Coupling (205-02 Rear Axle/Differential, Removal and Installation).

C2 CHECK THE ACTIVE TORQUE COUPLING SOLENOID CIRCUITS FOR A SHORT TO VOLTAGE

Disconnect the all-wheel drive relay module C4379. The ignition is on. Action: Click to display the connectors Positive lead Measurement/Action Negative lead C4379-5 Ground C4379-8 Ground Is there voltage present? Yes REPAIR the circuit. No GO to C3

C3 CHECK THE ACTIVE TORQUE COUPLING SOLENOID CIRCUITS FOR A SHORT TO GROUND

Action: Click to display the connectors Positive lead Measurement/Action Negative lead C4379-5 Ground C4379-8 Ground Is the resistance greater than 10000 Ohms? Yes GO TO C4 No REPAIR the circuit.

C4 CHECK THE ACTIVE TORQUE COUPLING SOLENOID CIRCUITS FOR AN OPEN CIRCUIT

Action: Click to display the connectors Positive lead Measurement/Action Negative lead C4379-5 C4347-1 C4379-8 C4347-2 Is the resistance less than 3 ohms? Yes GO to C5 No REPAIR the open circuit.

C5 CHECK THE ACTIVE TORQUE COUPLING SOLENOID CIRCUITS FOR A SHORT CIRCUIT TOGETHER

Action: Click to display the connectors Positive lead Measurement/Action Negative lead C4379-5 C4379-8 Is the resistance greater than 10000 Ohms? Yes GO to C6 No REPAIR the circuits.

C6 CHECK THE PCM (POWERTRAIN CONTROL MODULE) OPERATION

Ignition OFF. Disconnect all PCM connectors. Repair: corrosion (install new connector or terminals - clean module pins) damaged or bent pins - install new terminals/pins backed-out pins - install new pins as necessary Reconnect all PCM, all-wheel drive relay module and active torque coupling (ATC) solenoid connectors. Make sure they are fully seated and locked. PERFORM the all-wheel drive cycle. REFER TO: All-Wheel Drive (AWD) Systems (308-07A). and determine if the concern remains. Is the concern still present? Yes CHECK OASIS for applicable TSBs. If a TSB exists for this concern, STOP this test and FOLLOW the TSB instructions. If no TSB addresses this concern, INSTALL a new all-wheel drive relay module. REFER TO: All-Wheel Drive Module — 2 L Duratorq-TDCi (110 kW/150 L PS) (308-07A). CLEAR the DTCs. PERFORM the all-wheel drive cycle, REFER TO: All-Wheel Drive (AWD) Systems (308-07A). If the DTC returns, Click here to access the guided routine (PCM). Internet Explorer version 11 or later is required to perform this Pinpoint test. No The system is currently operating correctly. The concern may have been caused by module connections. ADDRESS the root cause of any connector or terminal issues.

DTCs P188C, P188D

For wiring diagrams and connector information, refer to Section 34 of the wiring diagrams.

Normal Operation and Fault Symptoms

The all-wheel drive system uses data from other systems as inputs to the PCM. The PCM uses these inputs to determine the appropriate time to send a signal and energize the all-wheel drive relay module to the active torque coupling (ATC) solenoid.

DTC Fault Trigger Conditions

Trouble Code	Description	Fault Trigger Conditions
P188C	All Wheel Drive Relay Module Communication Circuit	When the PCM detects an open circuit, a short to ground or a voltage in the control circuit.
P188D	All Wheel Drive Relay Module Feedback Circuit	When the PCM detects an open circuit, a short to ground or a voltage in the feedback circuit.

Possible Causes

• Wiring, Terminals or Connectors
• All-wheel drive relay module
• PCM

Visual Inspection and Preliminary Diagnosis

• BJB fuse 12 (15A)

PINPOINT TEST D: AWD (ALL WHEEL DRIVE) SIGNAL CIRCUIT FAULT

D1 CHECK THE ALL-WHEEL DRIVE (AWD) RELAY VOLTAGE CIRCUIT

Ignition OFF. Disconnect the all-wheel drive relay module C4379. Inspect the connectors for damage or terminal pushout, corrosion, loose wires, and missing or damaged seals. The ignition is on. Action: Positive lead Measurement/Action Negative lead C4379-1 Ground Is the voltage greater than 11 volts? Yes GO to D2 No CHECK that BJB fuse 12 (15A) is good. If good, REPAIR the open circuit. If not good, CONSULT the wiring diagrams to determine the possible causes of the short circuit. CLEAR the DTCs.

D2 CHECK THE ALL-WHEEL DRIVE (AWD) RELAY MODULE GROUND CIRCUIT FOR AN OPEN CIRCUIT

Action: Click to display the connectors Positive lead Measurement/Action Negative lead C4379-1 C4379-4 Is the voltage greater than 11 volts? Yes GO to D3 No REPAIR the circuit.

D3 CHECK THE ALL-WHEEL DRIVE (AWD) RELAY MODULE CONTROL AND FEEDBACK CIRCUITS FOR A SHORT TO VOLTAGE

The ignition is on. Action: Click to display the connectors Positive lead Measurement/Action Negative lead C4379-1 C4379-4 Is there voltage present? Yes GO to D4 No REPAIR the circuit.

D4 CHECK THE ALL-WHEEL DRIVE (AWD) RELAY MODULE CONTROL AND FEEDBACK CIRCUITS FOR A SHORT TO GROUND

Action: Click to display the connectors Positive lead Measurement/Action Negative lead C4379-6 Ground C4379-3 Ground Is the resistance greater than 10000 Ohms? Yes GO to D5 No REPAIR the circuit.

D5 CHECK THE ALL-WHEEL DRIVE (AWD) RELAY MODULE CONTROL AND FEEDBACK CIRCUITS FOR AN OPEN CIRCUIT

Disconnect PCM 1.5 L C1915B. Disconnect PCM 2 L C1381B. Disconnect PCM 2.5 L C1551B. Disconnect PCM 2.7 L C1231B. Action: Click to display the connectors For 1.5 L Positive lead Measurement/Action Negative lead C4379-6 C1915B-46 C4379-3 C1915B-60 Click to display the connectors For 2 L Positive lead Measurement/Action Negative lead C4379-6 C1381B-46 C4379-3 C1381B-60 Click to display the connectors For 2.5 L Positive lead Measurement/Action Negative lead C4379-6 C1551B-46 C4379-3 C1551B-60 Click to display the connectors For 2.7 L Positive lead Measurement/Action Negative lead C4379-6 C1231B-46 C4379-3 C1231B-60 Is the resistance less than 3 ohms? Yes GO to D6 No REPAIR the circuit.

D6 CHECK THE ALL-WHEEL DRIVE (AWD) RELAY MODULE CONTROL AND FEEDBACK CIRCUITS FOR A SHORT CIRCUIT TOGETHER

Action. Click to display connectors Positive lead Measurement/Action Negative lead C4379-6 C4379-3 Is the resistance greater than 10000 Ohms? Yes GO to D3 No CHECK OASIS for applicable TSBs. If a TSB exists for this concern, STOP this test and FOLLOW the TSB instructions. If no TSB resolves this concern, Click here to access the guided routine (PCM). Internet Explorer version 11 or later is required to perform this Pinpoint test.

D7 CHECK THE PCM (POWERTRAIN CONTROL MODULE) FOR PROPER OPERATION

Ignition OFF. Disconnect all PCM connectors. Check the following: corrosion (install new connector or terminals - clean module pins) damaged or bent pins - install new terminals/pins backed-out pins - install new pins as necessary Connect all PCM connectors. Make sure they are fully seated and locked. PERFORM the all-wheel drive cycle. REFER TO: All-Wheel Drive Systems — Operation and Component Description (308-07A All-Wheel Drive Systems, Description and Operation). and determine if the concern remains. Is the concern still present? Yes CHECK OASIS for applicable TSBs. If a TSB exists for this concern, STOP this test and FOLLOW the TSB instructions. If no TSB resolves this concern, Click here to access the guided routine (PCM). Internet Explorer version 11 or later is required to perform this Pinpoint test. No The system is currently operating correctly. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.

Vehicle binds in turns or resists steering/surges or jerks on straight-line driving

For wiring diagrams and connector information, refer to Section 34 of the wiring diagrams.

Normal Operation and Fault Symptoms

The all-wheel drive system is an active system, meaning it not only reacts to wheel slip between the front and rear axles, but also has the ability to anticipate wheel slip and transfer torque to the rear wheels before slip occurs. The all-wheel drive system is active at all times and requires no operator input. The all-wheel drive system continuously monitors vehicle conditions and automatically adjusts torque distribution between the front and rear wheels. During normal operation, most of the torque is sent to the front wheels. If wheel slip is detected between the front and rear wheels, if the vehicle is accelerating, or if the vehicle is being steered, the all-wheel drive system increases and distributes torque to the rear wheels as needed. When the all-wheel drive system is operating normally, there should be no noticeable speed difference between the front and rear axles when starting or driving on any level surface. Traction should be similar to a part-time 4WD system in 4H (4X4 HIGH), but without binding in turns.

AWD_CLTCH_CMD PID percentage displayed on the scan tool is an inverse value. 95% = clutch released, 5% = clutch fully engaged.

Possible Causes

• Wiring, Terminals and Connectors
• Wheels/Tires
• ABS system
• All-wheel drive relay module
• Active Torque Coupling (ATC) Clutch

Visual Inspection and Preliminary Diagnosis

• Wheel Speed Sensor Wiring Harness

PINPOINT TEST E: VEHICLE DRAGS OR RESISTS TURNING/SHUDDERS OR JERKS IN A STRAIGHT LINE

E1 CHECK REAR WHEEL TORQUE

Ignition OFF. Disconnect the active torque coupling (ATC) solenoid C4347. Inspect the connector for damage or spread terminals, corrosion, loose wires, and missing or damaged seals. Drive the vehicle straight on a dry paved road. Is the shudder or vibration still present? Yes REFER TO: Rear Axle and Differential (205-02 Rear Axle/Differential, Diagnosis and Testing). No GO to E2

E2 CHECK PTU CLUTCH CONTROL PID

Ignition OFF. Connect the Active Torque Coupling (ATC) solenoid C4347. The ignition is on. Using the diagnostic scan tool, monitor the AWD_CLTCH_CMD# PID. Drive the vehicle at a steady 5 mph (8 km/h) through tight turns on a dry paved road while monitoring the Active Torque Coupling (ATC) solenoid duty cycle. Is the duty cycle less than 80%? Yes GO to E3 No GO to Pinpoint Test B

E3 CHECK WHEEL SPEED CORRECTLY

Drive the vehicle at 30 mph (48 km/h) and 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 1.2 mph (2 km/h) of each other? Yes GO to E4 No GO to Pinpoint Test B

E4 CHECK ALL-WHEEL DRIVE (AWD) RELAY MODULE OPERATION

Disconnect the all-wheel drive relay module C4379. Disconnect the active torque coupling (ATC) solenoid C4347. Check the following: corrosion (install new connector or terminals - clean module pins) damaged or bent pins - install new terminals/pins backed-out pins - install new pins as necessary Connect the All-Wheel Drive (AWD) Relay Module C4379. Connect the Active Torque Coupling (ATC) solenoid C4347 and make sure it is installed correctly. PERFORM the all-wheel drive cycle. REFER TO: All-Wheel Drive Systems — Operation and Component Description (308-07A All-Wheel Drive Systems, Description and Operation). and determine if the concern remains. Is the concern still present? Yes INSTALL a new All-Wheel Drive (AWD) relay module. REFER TO: All-Wheel Drive (AWD) Module (308-07A All-Wheel Drive Systems, Removal and Installation). No The system is currently operating correctly. The concern may have been caused by a loose or corroded connector. ADDRESS the root cause of any connector or pin issues.

P182B, P182K, P182D, P183D

For wiring diagrams and connector information, refer to Section 34 of the wiring diagrams.

Normal Operation and Fault Symptoms

The Power Transfer Unit (PTU) Fluid Temperature Sensor is located in the Power Transfer Unit (PTU) (6F50/55 only). It is a temperature-sensitive device called a thermistor. The sensor resistance value changes with temperature. The PCM monitors the voltage at the PTU fluid temperature sensor to determine the Power Transfer Unit (PTU) fluid temperature.

AWD_CLTCH_CMD PID percentage displayed on the scan tool is an inverse value. 95% = clutch released, 5% = clutch fully engaged.

DTC Fault Trigger Conditions

Trouble Code	Description	Fault Trigger Conditions
P182B	Transfer Case Fluid Temperature Sensor Circuit Range/Performance	This DTC sets when the PCM detects an open, short to ground or a voltage present in the sensor circuit.
P182C	Transfer Case Fluid Temperature Sensor Circuit Low	This DTC sets when the PCM detects a short to ground, open or low voltage in the sensor circuit.
P182D	Transfer Case Fluid Temperature Sensor Circuit High Signal Level	This DTC sets when the PCM detects a high voltage in the sensor circuit.
P183D	Transfer Case Fluid Overtemperature	This DTC sets in the PCM when the PTU fluid temperature exceeds the maximum operating temperature.

Possible Causes

• Wiring, Terminals and Connectors
• Power Transfer Unit (PTU) Fluid Temperature Sensor
• PCM

Visual Inspection and Preliminary Diagnosis

• Power Transfer Unit (PTU) Fluid Temperature Sensor Wiring Harness
• PTU operation is normal and quiet
• PTU fluid level

PINPOINT TEST F: P182B, P182C, P182D, P183D

F1 RETRIEVE AND RECORD ALL DTCS

Using the diagnostic scan tool, retrieve all DTCs. Is DTC P182B, P182C, P182D and/or P183D present? Yes For DTCs P182B, P182C, P182D GO to F2. For DTC P183D ONLY GO to F6. No The system is now operating correctly. Confirm that the power transfer unit is not overheating due to a mechanical concern. REFER TO: Power Transfer Unit (308-07C Power Transfer Unit - 6-Speed Automatic Transmission - 6F50/6F55, Diagnosis and Testing).

F2 CHECK THE PTU FLUID TEMPERATURE SENSOR SIGNAL VOLTAGE

Ignition OFF. Disconnect the PTU C1831. Inspect the connector for damage or spread terminals, corrosion, loose wires, and missing or damaged seals. The ignition is on. Action: Click to display the connectors Positive lead Measurement/Action Negative lead C1831-1 Ground Is the voltage greater than 4.1 volts? Yes GO to F3 No GO to F4

F3 CHECK THE PTU FLUID TEMPERATURE SENSOR GROUND CIRCUIT FOR AN OPEN

Action: Click to display the connectors Positive lead Measurement/Action Negative lead C1831-1 C1831-2 Is the voltage greater than 4.1 volts? Yes GO to F5 No REPAIR the circuit.

F4 CHECK THE PTU FLUID TEMPERATURE SENSOR SIGNAL CIRCUIT FOR AN OPEN

Ignition OFF. Disconnect the PCM C1231B. Engine 2.7 L, measure: Click to display connectors Positive lead Measurement/Action Negative lead C1831-1 C1231B-76 Is the resistance less than 3 ohms? Yes GO to F5 No REPAIR the circuit.

F5 CHECK THE PTU FLUID TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND

Action: Click to display the connectors Positive lead Measurement/Action Negative lead C1831-1 Ground Is the resistance greater than 10000 Ohms? Yes GO to F6 No REPAIR the circuit.

F6 CHECK THE PTU FLUID TEMPERATURE SENSOR RESISTANCE

Action: Positive lead Measurement/Action Negative lead PTU fluid temperature sensor component side, pin 1 PTU fluid temperature sensor component side, pin 2 Temperature C Temperature F MIN Ohms MAX Ohms MIN Volts MAX Volts -40 -40 2.541 M 4.545 M 4,96 4,98 -30 -22 1.367 M 2.337 M 4,93 4,96 -20 -4 766K 1.255 M 4,87 4,92 -10 14 444.9K 701.4K 4,78 4,86 0 32 267.1K 406.2K 4,65 4,77 10 50 164K 241.2K 4,46 4,62 20 68 103.6K 147.8K 4.19 4.40 25 77 83.21K 116.9K 4.03 4,27 30 86 67.23K 116.9K 3,85 4.12 40 104 44.67K 93.12k 3,45 3,75 50 122 30.35K 60.22K 3.01 3,33 60 140 21.04K 39.88K 2,56 2,87 70 158 14.86K 26.99K 2.13 2.14 80 176 10.68K 18.64K 1,74 1,98 90 194 7.79K 13.11K 1,40 1,60 100 210 5781 93.85K 1.12 1,27 110 230 4345 5038 0,89 1.01 120 248 3308 3771 0,71 0,79 130 266 2549 2859 0,57 0,63 140 284 1987 2194 0,45 0,49 150 302 1565 1703 0,36 0,39 Does the resistance match the temperature specification? Yes Click here to access the guided routine (PCM). Internet Explorer version 11 or later is required to perform this Pinpoint test. No INSTALL a new Power Transfer Unit (PTU) fluid temperature sensor.