C1438
C1438-TRANSFER CASE DIFFERENTIAL CLUTCH WORN
For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.
Theory of Operation
The MP3010 is a one speed On Demand Electro-Mechanical Transfer Case. Torque is always sent to the rear axle but can be varied to the front axle from 0 to 100% depending on the situation. Under normal driving conditions the torque is split 47/53% front to rear. This split is varied based on but not limited to the following inputs: steering angle, driveline torque, wheel slip and vehicle speed. As steering angle increases the amount of torque sent to the front axle is decreased to prevent binding with a minimum split of 0/100. If a slip event is detected with high steering angle the transfer case will activate the clutch to stop the slip. During Regan braking the split is 50/50% front to rear above 30 km/h (19 mph) regardless of steering angle. Below 30 km/h (19 mph) the split modified by steering angle to a minimum of 10/90% to prevent binding but maintain vehicle stability.
- When Monitored:
The ignition on, engine running. No under-voltage over-voltage, and/or encoder error DTCs present.
- Set Condition:
The Final Drive Control Module (FDCM) is unable to fully lock the Transfer Case because the Transfer Case clutch is worn.
WARNING: On vehicles equipped with the high voltage system, you must thoroughly read and follow all High Voltage Safety procedures. In addition, before performing any diagnostic or service procedure near a high voltage component, you must perform the High Voltage Power Down. Failure to follow these instructions may result in possible serious or fatal injury
1. DTC IS ACTIVE
NOTE: Diagnose and repair any system voltage or Transfer Case related DTCs in the FDCM before continuing with this test.
1. Ignition on, engine running.
2. With the scan tool, erase DTCs.
3. Test drive the vehicle.
4. With the scan tool, read DTCs.
Does this DTC reset?
Yes
- Go To 2
No
- Go To 9
2. (K504) DRIVETRAIN 5 VOLT SUPPLY CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off to the lock position
2. Disconnect the FDCM C1 harness connector.
3. Disconnect the Transfer Case Encoder harness connector.
4. Measure the resistance of the (K504) Drivetrain 5 Volt Supply circuit between the Transfer Case Encoder harness connector and the FDCM C1 harness connector.
Is the resistance above 5.0 Ohms?
Yes
- Repair the high resistance in the (K504) Drivetrain 5 Volt Supply circuit.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test.
No
- Go To 3
3. (T313) MODE SENSOR SIGNAL CIRCUIT OPEN OR HIGH RESISTANCE
1. Turn the ignition off to the lock position
2. Measure the resistance of the (T313) Mode Sensor Signal circuit between the Transfer Case Encoder harness connector and the FDCM C1 harness connector.
Is the resistance above 5.0 Ohms?
Yes
- Repair the high resistance in the (T313) Mode Sensor Signal circuit.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test.
No
- Go To 4
4. (K594) DRIVETRAIN SENSOR RETURN CIRCUIT OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (K594) Drivetrain Sensor Return circuit between the Transfer Case Encoder harness connector and the FDCM C1 harness connector.
Is the resistance above 5.0 Ohms?
Yes
- Repair the high resistance in the (K594) Drivetrain Sensor Return circuit.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test.
No
- Go To 5
5. (T315) STEP MOTOR CONTROL B CIRCUIT OPEN OR HIGH RESISTANCE
1. Disconnect the FDCM C2 harness connector.
2. Measure the resistance of the (T315) Step Motor Control B circuit from the Transfer Case Motor harness connector to the FDCM C2 harness connector.
Is the resistance above 5.0 Ohms?
Yes
- Repair the (T315) Step Motor Control B circuit for an open or high resistance.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test.
No
- Go To 6
6. (T316) STEP MOTOR CONTROL C CIRCUIT OPEN OR HIGH RESISTANCE
1. Measure the resistance of the (T316) Step Motor Control C circuit from the Transfer Case Motor harness connector to the FDCM C2 harness connector.
Is the resistance above 5.0 Ohms?
Yes
- Repair the (T316) Step Motor Control C circuit for an open or high resistance.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test.
No
- Go To 7
7. TRANSFER CLUTCH WORN
1. Connect the Transfer Case Motor harness connector.
2. Connect the FDCM C1 harness connector.
3. Connect the FDCM C2 harness connector.
4. Test drive the vehicle.
5. With the scan tool, monitor the encoder voltage in the FDCM.
Is the encoder voltage between 4.625 and 4.750 volts?
Yes
- Replace the worn clutch pack assembly.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test.
No
- Go To 8
8. TRANSFER CASE MOTOR
1. Measure the resistance between the (T315) Step Motor Control B circuit and the (T316) Step Motor Control C circuit at the FDCM C2 harness connector.
Is the resistance below 5.0 Ohms?
Yes
- Replace the Final Drive Control Module (FDCM).
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test.
No
- Replace the Transfer Case Motor.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test.
9. INTERMITTENT WIRING HARNESS AND CONNECTORS
1. The conditions necessary to set this DTC are not present at this time.
2. Using the wiring diagram/schematic as a guide, inspect the wiring harness and connectors.
3. Wiggle test the wiring harness and connectors while monitoring the scan tool data relative to this circuit.
4. Look for the data to change or for the DTC to reset during the wiggle test.
Were any problems found?
Yes
- Repair as necessary.
- Perform the TRANSFER CASE VERIFICATION TEST Transfer Case Verification Test.
No
- Test complete.