Transfer Case - Bw 4477 Cadillac CTS II

Approximate Fluid Capacities

Fastener Tightening Specifications

Spacer and Shim Specifications

Adhesives, Fluids, Lubricants, and Sealers

Scheme 1

Scheme 2

Scheme 3

DIAGNOSTIC CODE INDEX

DIAGNOSTIC CODE INDEX

Diagnostic Instructions

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

Diagnostic Fault Information

Circuit/System Description

The transfer case normally operates in 2WD mode. When all wheel drive (AWD) is requested, the transfer case control module (TCCM) sends 12 volts to the transfer case clutch coil (TCCC) via the clutch coil control circuit. This engages the transfer case clutch assembly through a ball and cam apply system. The TCCC is controlled by a high and low side driver. Both circuits must be activated to engage the system.

Conditions for Running the DTC

1. The ignition is ON.
2. System voltage is between 9 and 16 volts.

Conditions for Setting the DTC

The voltage seen by the transfer case control module is below 0.30 volts or above 0.70 volts for more than 5 seconds.

Action Taken When the DTC Sets

1. The vehicle will be in 2WD mode while the fault is present.
2. The SERVICE 4WD indicator remains illuminated for the remainder of the current ignition cycle.

Conditions for Clearing the DTC

1. The TCCM clears the DTC if the condition for setting the DTC is not currently present.
2. A history DTC clears after 40 consecutive warm up cycles without a fault present.
3. All DTCs can be cleared using a scan tool.
4. Clearing DTCs will also clear failure records.

Diagnostic Aids

1. Check failure records for further information on the conditions present when this DTC set.
2. Make sure system voltage is above 10.5 volts as Special Functions will not work correctly if the system is below this voltage.
3. The TCCM comes preprogrammed and is not flashable.

Reference Information

Schematic Reference

Transfer Case Control Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 35616: GM-Approved Terminal Test Kit

Circuit/System Testing

1. Ignition OFF, disconnect the X1 connector at the TCCM. Test terminals 4 and 5 X1, harness side, for proper pin retention using J 35616-2A: probe. Refer to «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs) . If both terminals test normal, reconnect the X1 connector at the TCCM.
2. Disconnect the X1 connector at the TCCC. Test terminals A and B X1, harness side, for proper pin retention using J 35616-4A. Refer to «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs) .
3. Ignition on. Using J 35616-4A: probe, connect a DMM between the clutch coil control circuit, pin A X1 TCCC, harness side, and a good ground. Using the scan tool special functions, command the clutch control ON. The DMM should indicate battery voltage. If the DMM indicates less than battery voltage, test the clutch coil control circuit for an open, high resistance or short to ground. If the circuit tests normal, replace the TCCM.
4. Using the scan tool special functions command the clutch control OFF. The DMM should indicate 2-4 volts. If the DMM indicates greater than 2-4 volts when it is commanded OFF, test the clutch coil control circuit for a short to voltage. If the circuit tests normal, replace the TCCM.
5. Using J 35616-4A: probe, connect a DMM between the clutch coil return circuit, pin B X1 TCCC harness side, and a good ground. Put the DMM on the audible selection for testing resistance. Using the scan tool special functions, command the clutch return circuit ON. The DMM should indicate continuity. If the DMM did not indicate continuity, test the clutch coil return circuit for an open, high resistance or a short to voltage. If the circuit tests normal, replace the TCCM.
6. Using the scan tool special functions, command the clutch return circuit OFF. The DMM should NOT indicate continuity. If the DMM indicates continuity, test the clutch coil return circuit for a short to ground. If the circuit tests normal, replace the TCCM.
7. Using J 35616-5: probe, test for 2-5 ohms of resistance between TCCC, pins A and B X1 TCCC. If the resistance is not within the specified range, replace the transfer case. Refer to «Transfer Case Assembly Replacement»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477) .

Repair Procedures

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for TCCM replacement, setup, and programming.
2. «Transfer Case Assembly Replacement»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

A transfer case will be equipped with one of nine different value transfer case resistors. The resistor value the unit is equipped with is dependent upon manufacturing tolerances and is a result of end of line testing at the manufacturer. A 5-volt reference is supplied to the resistor, and then it is read back via the clutch resistor signal circuit giving the module the voltage indicating what resistor value is present. Having the wrong resistor may cause the system to be less responsive to certain driving situations and also could damage the front axle. Depending on the resistor value used a customer may never know the system is not performing at optimum efficiency.

1. The ignition is ON.
2. System voltage is 9-16 volts.

DTC C0896 is not set.

1. System performance may be affected.
2. No DIC messages will be displayed.

1. The transfer case shift control module clears the DTC if the conditions for setting the DTC are not currently present.
2. A history DTC clears after 40 consecutive warm up cycles without a fault present.
3. All DTCs can be cleared using a scan tool.
4. Clearing DTCs will also clear failure records.

1. Check failure records for further information on the conditions present when this DTC set.
2. This fault will likely not be noticed by the driver; however you can address this fault by looking at the clutch resistor value on the scan tool via the scan tool data list. The voltages should never be below 0.20 volts or above 4.60 volts.
3. Check inline connector X103 for bent pins, corrosion, or other damage.
4. Check for bent pins inside the resistor.

Schematic Reference

Transfer Case Control Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

The clutch coil resistor can be checked by measuring the resistance of the resistor with a DMM by putting one lead on pin B and the other on pin A, the correct resistance is embossed in the resistor. If the system is operating normally you should see a voltage range of 0.20-4.60 volts on the clutch resistor value via the scan tool data list. The value for the 5-volt reference circuit should be 4.8-5.0 volts. Further explanation is given in component testing. Should you see a voltage out of range you should check the 5-volt reference circuit and the signal circuit for an open, high resistance, short to voltage, or short to ground.

1. See component testing for further direction.

Component Testing

Clutch Resistor values can vary up to 3 percent and not set a DTC. Resistor values falling within the dead band area will set this DTC.

Clutch resistors vary depending on clutch stack up during manufacture. View the clutch resistor values on the scan tool this will allow you to properly diagnose the circuit. A system operating within the suggested voltage range will be operating as designed.

Clutch Style

Dead Bands

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TCSCM replacement, setup, and programming

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

The temperature sensor is a variable resistor, as the temperature increases the resistance decreases and as the temperature decreases the resistance increases.

1. The ignition is ON.
2. System voltage is 9-16 volts.

1. DTC C0896 is not set.
2. System voltage is above 9 volts and below 16 volts.
3. For a short to voltage or actual transfer case overheat condition, the DTC will set immediately once 154°C (309°F) has been met or exceeded.
4. The vehicle has been driven 10 minutes at 73 km/h (45 mph) or higher for an open or short to ground condition.

1. System backup will read the transmission oil temperature.
2. The SERVICE 4WD indicator is set.
3. If the transfer case oil temperature DTC is set due to an actual overheat condition and not an electrical fault then the AWD off indicator will be set.

1. The transfer case shift control module clears the DTC if the conditions for setting the DTC are not currently present.
2. A history DTC clears after 40 consecutive warm up cycles without a fault present.
3. All DTCs can be cleared using a scan tool.
4. Clearing DTCs will also clear failure records.

1. Check failure records for further information on the conditions present when this DTC set.
2. If the transfer case oil temperature sensor circuits are open or have high resistance the scan tool will indicate -40°C.
3. Check inline connector X103 for bent pins, corrosion, or other damage.
4. Check the transfer case temperature sensor for possible bent pins.
5. If the transfer case oil temperature circuits are shorted to voltage the scan tool will read 154°C.

Schematic Reference

Transfer Case Control Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information.

1. With the key off disconnect the transfer case oil temperature sensor at the transfer case.
2. Turn the ignition on and test pin B at the transfer case for voltage using a DMM the voltage reading should be 4.8 to 5.2 volts. If the voltage is out of range check the 5 volt reference circuit for a short to ground, open, high resistance, or short to battery. This can be done by using a DMM and testing from pin B at the transfer case and X1 pin 9 at the transfer case shift control module.
3. If the 5 volt reference circuit measured within specifications then using a fused jumper, jump pin B to pin A at the transfer case. With these two pins jumped read the transfer case oil temperature on the scan tool under transfer case data display. If the temperature reads 154°C then the circuit is testing good. If it does not show this temperature then repair the temperature sensor signal circuit for an open, high resistance, short to ground, or short to voltage. This can be done by using a DMM and testing from pin B at the transfer case and X1 pin 1 at the transfer case shift control module. If the temperature checks good replace the transfer case temperature sensor. If voltage on the 5 volt reference is out of range or the temperature is not indicating correctly go to the next step.
4. If both the 5 volt reference circuit and the temperature sensor signal circuit test good and the voltage or temperature are indicated out of range in the above two steps then replace the transfer case shift control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

1. «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) for TCSCM replacement, setup, and programming.
2. «Transfer Case Fluid Temperature Sensor Replacement»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This DTC indicates an EEPROM failure where diagnostic data is stored.

1. The ignition is ON.
2. System voltage is 9-16 volts.

The EEPROM has failed and diagnostic data as well as other assorted data can not be stored.

1. Activation is still disabled until the conditions for setting the DTC are no longer present.
2. The SERVICE AWD indicator remains illuminated for the remainder of the current ignition cycle.

1. The transfer case shift control module clears the DTC if the conditions for setting the DTC are not currently present.
2. A history DTC clears after 40 consecutive warm up cycles without a fault present.
3. All DTCs can be cleared using a scan tool.
4. Clearing DTCs will also clear failure records.

1. Check failure records for further information on the conditions present when this DTC set.
2. It is sometimes possible to set this DTC falsely due to low voltage. Attempt to clear this DTC and retest.

Schematic Reference

Transfer Case Control Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information.

If this DTC sets attempt to clear the DTC and Retest.

1. If the DTC is cleared, but then resets then replace the transfer case control module.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TCSCM replacement, setup, and programming.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

This DTC is set up to detect a high or low voltage situation. This could indicate a vehicle issue in which all electrical components would be affected. It could also be transfer case control module specific due to poor power or ground connections.

1. The ignition is ON.
2. System voltage is 7-18.5 volts.

The voltage is above 16 volts or below 9 volts for 4 seconds.

1. Shifting is disabled until the voltages change to be within the specifications.
2. The SERVICE AWD will not be illuminated.
3. If the voltage drops below 7 volts the transfer case shift control module will go offline and a Service AWD indicator would then be present because the transfer case shift control module would no longer be transmitting on the Serial Data Line.

1. The transfer case shift control module clears the DTC if the conditions for setting the DTC are not currently present.
2. A history DTC clears after 40 consecutive warm up cycles without a fault present.
3. All DTCs can be cleared using a scan tool.
4. Clearing DTCs will also clear failure records.

1. Check failure records for further information on the conditions present when this DTC set.
2. Check other modules for voltage related DTCs as this may indicate a system voltage issue.

Schematic Reference

Transfer Case Control Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information.

1. If the voltage is low check the voltage on other vehicle systems to determine if this is a vehicle wide condition and take appropriate actions. If this is transfer case specific check the ignition 3 feed to the transfer case control module and the ground for the transfer case control module for proper connections. The scan tool under transfer case data list can also be used to monitor battery voltage.
2. If the voltage is high, this is likely a vehicle issue such as an alternator problem or the vehicle has been hooked up improperly during a jump start.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Strategy Based Diagnostics

Review the system operation in order to familiarize yourself with the system functions. Refer to Transfer Case Description and Operation .

Visual/Physical Inspection

1. Inspect the easily accessible or visible system components for obvious damage, or for conditions which could cause the symptom.
2. Inspect the transfer case for the proper fluid. Refer to «Transfer Case Fluid Replacement»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477) .

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «No Correction for Slip in All-Wheel Drive Mode»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477)
2. «Service All-Wheel Drive Indicator Always On»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477)
3. «All-Wheel Drive Off Indicator Always On»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477)
4. «Transfer Case Popping Noise»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477__transfer-case-popping-noise)
5. «Transfer Case Whine or Rumble Noise»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477__transfer-case-whine-or-rumble-noise)
6. «Transfer Case Clunk During Acceleration and Deceleration»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477__transfer-case-clunk-during-acceleration-and)
7. «Transfer Case Leak Diagnosis»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477__transfer-case-leak-diagnosis)

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

When transfer case is in AWD mode the transfer case control module monitors the front wheel speeds and the rear wheel speeds. When a noticeable difference between the front and rear is seen the transfer case control module sends a PWM voltage to the clutch coil so it can apply the clutch in order to correct a slip condition. The slip condition is the difference in speed between the front and rear axles. The module has a thermal model based system so when the slip correction can not be made when a high percentage PWM signal has been sent, it will disable the system temporarily to prevent damage to the clutches.

1. Erratic wheel speed sensors can cause this condition to occur. Monitor the wheel speeds using the transfer case scan tool data list.
2. Make sure system voltage is above 10.5 volts as Special Functions will not work correctly if the system is below this voltage.

Schematic Reference

Transfer Case Control Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information.

1. Monitor the wheel speed sensors using the transfer case scan tool data list. If the wheel speeds are erratic or there is a large difference between front and rear then diagnose and repair as necessary. Check for EBCM DTCs as they have likely set for wheel speed performance.
2. While in a parking lot with a scan tool using transfer case special functions go to clutch coupling request and request 100%. Drive the vehicle while making sharp turns, if the vehicle binds on turns this indicates the system is working properly. If it does not bind on turns go to the next step.
3. If nothing is found with wheel speed performance then the clutches may be excessively worn. Refer to «Transfer Case Disassemble»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477) .
4. Repair as necessary.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Transfer Case Disassemble

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

If the service indicator needs to be turned on the transfer case shift control module sends a signal via the serial data line to the BCM which then sends a message to the instrument panel asking the I/P to command the Service AWD indicator.

Schematic Reference

Transfer Case Control Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information.

1. If the Service AWD indicator is on and there are no DTCs, using a scan tool check under transfer case data list to see if the transfer case shift control module is requesting the service AWD indicator. If the module will not communicate check the fuse for the transfer case as this would cause the transfer case control module to drop off the serial data line causing a service indicator.
2. If the fuse is good check the module power and grounds for proper connections as this could cause the same thing as a blown fuse.
3. If this checks OK then check all other U codes that may be set against the transfer case shift control module such as I/P, BCM, PCM, and follow the proper U code diagnostic.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for TCSCM replacement, setup, and programming.

1. Perform the «Diagnostic System Check - Vehicle»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures) prior to using this diagnostic procedure.
2. Review «Strategy Based Diagnosis»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) for an overview of the diagnostic approach.
3. «Diagnostic Procedure Instructions»(/cadillac/cts/ii-2007-2014/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__diagnostic-procedure-instructions) provides an overview of each diagnostic category.

If the AWD Off Indicator needs to be turned on the transfer case shift control module sends a signal via the serial data line to the BCM which then sends a message to the instrument panel asking the I/P to command the AWD Off Indicator. The AWD Off Indicator is turned on for three reasons, the transfer case has overheated, the transfer case has lost both rear wheel speeds and vehicle speed, the transfer case has lost the front wheel speeds.

Schematic Reference

Transfer Case Control Schematics

Connector End View Reference

Component Connector End Views

Electrical Information Reference

1. «Circuit Testing»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__circuit-testing)
2. «Connector Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__connector-repairs)
3. «Testing for Intermittent Conditions and Poor Connections»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__testing-for-intermittent-conditions-and-poor)
4. «Wiring Repairs»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-diagnostic-information-and-procedures__wiring-repairs)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information.

1. Check for any transfer case DTCs and diagnose as necessary.
2. Check for any U codes which may indicate the reason why wheel speed or vehicle speeds are missing and diagnose as necessary using the U code diagnostics.
3. Using a scan tool under transfer case data list look at the transfer case oil temperature. If the temperature is at or above 135°C (275°F) determine that the vehicle is not being used beyond its design intent. If this is not the case then the overheat condition may be due to excessively slipping clutches. Allow the transfer case to cool and retest. If the condition persists then disassemble the transfer case and repair as necessary. If an overheating issue is not present go to the next step.
4. Check the ECM and EBCM for DTCs as these modules will likely have set DTCs due to faulty wheel or vehicle speeds. Follow the proper diagnostics and repair as necessary.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Transfer Case Disassemble

Transfer Case Popping Noise

Transfer Case Whine or Rumble Noise

Transfer Case Clunk During Acceleration and Deceleration

Transfer Case Leak Diagnosis

Special Tools

DT-48371 Plug Wrench

Removal Procedure

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/cadillac/cts/ii-2007-2014/remont/ignition-switchsteering-lock/#general-information) .
2. Reposition the underbody insulation as necessary to gain access to the fill plug.
3. Remove the fill plug (6) using the DT-48371 .
4. Remove the drain plug (8).
5. Allow the transfer case to drain completely.

Installation Procedure

1. Apply sealant GM P/N 12378470, (Canadian P/N 10952622), or equivalent to the threads of the drain plug.
2. Install the drain plug (8) and tighten to 25 N.m (18 lb ft).
3. Fill the transfer case to the bottom of the fill plug hole with Mobil LT fluid GM P/N 88861950, (Canadian P/N 88861951).
4. Install the fill plug (6) and tighten with hand plus 1.25 turns using the DT-48371 .
5. Lower the vehicle.

Scheme 4

Scheme 5

1. Remove the right side instrument panel insulator. Refer to «Instrument Panel Insulator Replacement - Right Side (Left Hand Drive)»(/cadillac/cts/ii-2007-2014/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) or «Instrument Panel Insulator Replacement - Right Side (Right Hand Drive)»(/cadillac/cts/ii-2007-2014/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
2. Remove the electrical connectors (1) from the transfer case shift control module (4).
3. Remove the transfer case shift control module (1) from the instrument panel insulator (2).

1. Install the transfer case shift control module (1) to the instrument panel insulator (2).
2. Install the electrical connectors (1) to the transfer case shift control module (4).
3. Install the right side instrument panel insulator. Refer to «Instrument Panel Insulator Replacement - Right Side (Left Hand Drive)»(/cadillac/cts/ii-2007-2014/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) or «Instrument Panel Insulator Replacement - Right Side (Right Hand Drive)»(/cadillac/cts/ii-2007-2014/remont/exteriorinterior-trim/#instrument-panel-trim-and-console-trim) .
4. For module programming and setup information, refer to «Control Module References»(/cadillac/cts/ii-2007-2014/remont/communication-devices/#programming-and-setup-all-systems__control-module-references) .

1. Drain the transfer case fluid, if necessary. Refer to «Transfer Case Fluid Replacement»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477) .
2. Remove the exhaust system. Refer to «Exhaust System Replacement (LF1)»(/cadillac/cts/ii-2007-2014/remont/exhaust/#engine-exhaust-system) or «Exhaust System Replacement (Single)»(/cadillac/cts/ii-2007-2014/remont/exhaust/#engine-exhaust-system) or «Exhaust System Replacement (LLT)»(/cadillac/cts/ii-2007-2014/remont/exhaust/#engine-exhaust-system) .
3. Remove the rear propeller shaft. Refer to «Rear Propeller Shaft Replacement (RPO LLT/LF1with MX7 or MN6)»(/cadillac/cts/ii-2007-2014/remont/driveshaft-universal-joints/#propeller-shaft) or «Rear Propeller Shaft Replacement (RPO LLT, LF1 with MXO)»(/cadillac/cts/ii-2007-2014/remont/driveshaft-universal-joints/#propeller-shaft) .
4. Support the transmission with a suitable screw jack and a block of wood.
5. Remove the transmission mount-to-body bolts.
6. Disconnect the shift linkage at the control lever. Refer to «Shift Control Linkage Replacement (All Wheel Drive)»(/cadillac/cts/ii-2007-2014/remont/automatic-trans/#automatic-transmission-6l456l506l806l90-repair-instructions-on-vehicle) or «Shift Control Linkage Replacement (Rear Wheel Drive)»(/cadillac/cts/ii-2007-2014/remont/automatic-trans/#automatic-transmission-6l456l506l806l90-repair-instructions-on-vehicle) .
7. Using the jack, lower the transmission enough to access the transmission mount-to-transfer case mounting bolts.
8. Remove the vent hose from the transmission mount assembly.
9. Remove the transmission mount-to-transfer case mounting bolts.
10. Remove the transmission mount assembly from the vehicle.
11. Remove the front propeller shaft. Refer to «Front Propeller Shaft Replacement»(/cadillac/cts/ii-2007-2014/remont/driveshaft-universal-joints/#propeller-shaft) .
12. Disconnect the electrical connectors from the transfer case.
13. Using another suitable adjustable jack, support the transfer case.
14. Remove the transfer case bolts (1-6).
15. Remove the transfer case dampener (7).
16. Remove the transfer case (8).
17. Remove the transfer case gasket (9).

1. Apply grease GM P/N 1051344 (Canadian P/N 993037), or equivalent, on the input splines starting from the front edge to 10 mm inward in a continuous pattern around the inside diameter (ID) of the splines to completely fill the splines.
2. Install the transfer case gasket (9).
3. Install the transfer case (8).
4. Install the transfer case dampener (7).
5. Install the transfer case bolts (1-6) and tighten to 60 N.m (44 lb ft).
6. Remove the adjustable jack from the transfer case.
7. Connect the electrical connectors to the transfer case.
8. Install the transmission mount assembly. Refer to «Transmission Mount Replacement (Except AWD and CTS-V)»(/cadillac/cts/ii-2007-2014/remont/automatic-trans/#automatic-transmission-6l456l506l806l90-repair-instructions-on-vehicle) or «Transmission Mount Replacement (Automatic AWD)»(/cadillac/cts/ii-2007-2014/remont/automatic-trans/#automatic-transmission-6l456l506l806l90-repair-instructions-on-vehicle) .
9. Install the vent hose to the transmission mount assembly.
10. Remove the jack and block of wood from under the transmission.
11. Connect the shift linkage to the control lever. Refer to «Shift Control Linkage Replacement (All Wheel Drive)»(/cadillac/cts/ii-2007-2014/remont/automatic-trans/#automatic-transmission-6l456l506l806l90-repair-instructions-on-vehicle) or «Shift Control Linkage Replacement (Rear Wheel Drive)»(/cadillac/cts/ii-2007-2014/remont/automatic-trans/#automatic-transmission-6l456l506l806l90-repair-instructions-on-vehicle) .
12. Install the front propeller shaft. Refer to «Front Propeller Shaft Replacement»(/cadillac/cts/ii-2007-2014/remont/driveshaft-universal-joints/#propeller-shaft) .
13. Install the rear propeller shaft. Refer to «Rear Propeller Shaft Replacement (RPO LLT/LF1with MX7 or MN6)»(/cadillac/cts/ii-2007-2014/remont/driveshaft-universal-joints/#propeller-shaft) or «Rear Propeller Shaft Replacement (RPO LLT, LF1 with MXO)»(/cadillac/cts/ii-2007-2014/remont/driveshaft-universal-joints/#propeller-shaft) .
14. Install the exhaust system. Refer to «Exhaust System Replacement (LF1)»(/cadillac/cts/ii-2007-2014/remont/exhaust/#engine-exhaust-system) or «Exhaust System Replacement (Single)»(/cadillac/cts/ii-2007-2014/remont/exhaust/#engine-exhaust-system) or «Exhaust System Replacement (LLT)»(/cadillac/cts/ii-2007-2014/remont/exhaust/#engine-exhaust-system) .
15. Refill the transfer case with fluid. Refer to «Transfer Case Fluid Replacement»(/cadillac/cts/ii-2007-2014/remont/transfer-case/#transfer-case-bw-4477) .

Scheme 6

Dampener and Rear Output Flange Removal

Scheme 7

Vent Assembly, Drain Plug, Fill Plug, and Temperature Sensor Removal

Scheme 8

Front Output Shaft Removal

Scheme 9

Cover, Apply Cam, and Clutch Pack Removal

Scheme 10

Chain, Sprockets, Oil Pump, and Input Shaft Removal

Scheme 11

Coil Removal

Scheme 12

Chain Snubber and Vent Baffle Removal

Scheme 13

Transfer Case and Cover Cleaning and Inspection

Scheme 14

Clutch Components Cleaning and Inspection

Scheme 15

Chain, Sprockets, and Snubber Cleaning and Inspection

Scheme 16

Input Shaft and Front Output Shaft Cleaning and Inspection

Scheme 17

Coil Assembly Cleaning and Inspection

Scheme 18

Oil Pump and Suction Pipe Assembly Cleaning and Inspection

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

Coil Installation

Scheme 26

Chain Snubber and Vent Baffle Installation

Scheme 27

Chain, Sprockets, Oil Pump, Input Shaft, and Front Output Shaft Installation

Scheme 28

Apply Cam, and Clutch Pack Installation

Scheme 29

Case Half and Front Output Shaft Hole Plug Installation

Scheme 30

Dampener and Rear Output Flange Installation

Scheme 31

Vent Assembly, Drain Plug, Fill Plug, and Temperature Sensor Installation

Scheme 32

Scheme 33

The Borg Warner (BW) model 4477, transfer case power take-off unit (PTU) is a 1-speed active transfer case.

An on demand torque biasing friction clutch is tuned through software calibrations. This allows features such as flexible clutch preload torque levels. This allows for vehicle speed dependent clutch torque levels to enhance system performance. For example, the system is calibrated to provide low clutch torque during low speed, low engine torque operation, and predetermined higher torque at greater speeds. This prevents crow-hop and binding at low speeds and provides higher torque biases at higher vehicle speeds, to enhance stability.

The BW 4477 clutch pack assembly contains a, predetermined selectable pressure plate, friction and reaction plates; serviced as an assembly. The clutch is controlled by pulse width modulated voltage through a coil, ball and cam apply system. Performance variation is reduced further through a selectable external in-line resistor. Matched to clutch system performance, the resistor fine tunes apply rates and maximum front wheel torque outputs. If the clutch pack assembly is replaced, a 12.7 k ohm clutch coil resistor should be used in place of the pre-existing resistor. If the resistor is replaced due to loss or damage without replacing the clutch pack, replace with one of the same resistance and refer to Transfer Case Clutch Coil Resistor Replacement .

The BW 4477 case halves are die-cast aluminum. Ball bearings support the input shaft, and front output shaft. An oil pump, driven by a 1-piece input/output shaft, pumps fluid through the shaft oil gallery for the clutch and bearing lubrication. This transfer case requires specific lubrication. Refer to Adhesives, Fluids, Lubricants, and Sealers .

Illustration Tool Number/Description DT-48553 Clutch Pack Measurement Adapter DT-48846 Output Seal Installer DT-48847 Pinion Flange Holder J-2619-A Slide Hammer w/Adapter J 8001 Dial Indicator Set J 8092 Driver Handle J 45278 Seal Remover J 46268 Output Seal Installer

Scheme 34

Scheme 35

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Diagnostic Procedure Instructions
• Component Connector End Views
• Circuit Testing
• Connector Repairs
• Testing for Intermittent Conditions and Poor Connections
• Wiring Repairs
• Control Module References
• Diagnostic Repair Verification
• Lifting and Jacking the Vehicle
• Component Fastener Tightening Caution
• Instrument Panel Insulator Replacement - Right Side (Left Hand Drive)
• Exhaust System Replacement (LF1)
• Rear Propeller Shaft Replacement (RPO LLT/LF1with MX7 or MN6)
• Shift Control Linkage Replacement (All Wheel Drive)
• Fastener Caution
• Machined Surface Damage Caution
• DTC C0399
• Transfer Case Popping Noise
• Transfer Case Whine or Rumble Noise
• Transfer Case Clunk During Acceleration and Deceleration
• Transfer Case Leak Diagnosis
• Approximate Fluid Capacities
• Adhesives, Fluids, Lubricants, and Sealers
• Spacer and Shim Specifications