Keep Those Trannys Rolling - July - 2017

Diagnosing Magna’s MP 3010 Transfer Case Control System

Last time, we looked at Magna Powertrain’s MP3010 transfer case system and what it takes to control its four wheel drive system. In this issue, we’re going to look at the diagnostic routines that help keep this four wheel drive system rolling down the road.

Transfer Case Shift Control Module (TCSCM)

The MP 3010 transfer case system is controlled by the transfer case shift control module (TCSCM) (Figure 1). This module uses several components to monitor and control the transfer case operation. These include (Figure 2):

  • transfer case shift control switch
  • two/four wheel drive increment sensor
  • actuator shaft position sensor
  • transfer case motor lock circuit
  • two/four wheel drive actuator
  • front axle actuator
  • vehicle speed signal

…and torque demand information from the PCM/ECM. Now let’s check out the diagnostic routines needed to keep this four wheel drive system rolling down the road.

Data Line Communication System

Diagnosing the MP3010 four wheel drive system starts by accessing the data line communication system (DLCS), or network, with a scan tool, through the data link connector (DLC; located in the lower left corner of the dash). The network provides access to all of the modules connected to it.

This particular vehicle, a 2015 Cadillac Escalade equipped with a 6.2L engine, a 6L80E transmission, and an MP3010 transfer case control system, has in excess of 50 modules connected to the network. Each of these modules share information with the other modules in the network.

The transfer case shift control module (TCSCM) monitors the shared information on the network to control the MP3010 four wheel drive system. Problems or codes in other modules connected to the network can interfere with the MP3010 four wheel drive system operation.

System Diagnosis

After connecting a scan tool to the DLC, you should be able to access the network and all modules connected to it. Be sure to scan, document, and clear all codes and messages from all modules before accessing the transfer case shift control module, because those codes or messages could interfere with system operation.

Once you’ve accessed the module, you may find codes in the system. Document and clear all codes and messages before checking the four wheel drive system operation.

After test-driving the vehicle, recheck the module for any codes or messages that were set during the test drive and repair them as needed.

Diagnostic Trouble Codes

Here’s a description of each of the transfer case codes:

B0770 (AWD Indicator Circuit), B0775 (4WD HI Indicator Circuit), and B0785 (2WD HI Indicator Circuit) — The module’s detected erratic voltage on the AWD, 4WD HI, or 2WD HI indicator circuits.

B2725 (Select Switch Circuit) — The module’s detected an erratic signal from the transfer case range select switch circuit.

P0698 or P0699 (Transfer Case Range Select Switch 5V Reference Circuit) — The module’s detected an erratic signal on the select switch 5V reference circuit.

C0306 (Range Actuator Control Circuit) — The module’s detected an erratic signal on the range actuator control circuits.

C0381 (Range Actuator System Calculated Temperature/Performance) — The module’s detected the range actuator motor is too hot.

C0321 or C0326 (Range Actuator Lock Circuit/Performance) — The module’s detected an erratic signal coming back from the range actuator lock circuit.

C0364 (Front Axle Actuator Circuit) — The module’s detected an erratic signal on the front axle actuator circuit.

C0379 (Front Actuator Switch Performance) — The module’s detected a fault in the front axle actuator indicator circuit.

C0374 (System Performance / High Temperature) — The module’s detected a mechanical fault in the transfer case system causing the system to overheat. This may be caused by a mechanical problem in the transfer case assembly (attempt to shift transfer case manually), high resistance in the range actuator motor, or a faulty module.

C0387 (Unable to Complete Shift) — The module was unable to complete the shift or range change as requested. This code is usually caused by a mechanical problem in the four wheel drive system. If no other codes are in the system, check the command going to range actuator motor.

C038D (Range Actuator Position Not Learned) — The module’s detected an internal programming fault. No external circuits are involved. This code is usually set when the module or range actuator assembly were replaced without performing the High/Low Clutch Reset Procedure.

C0392 (Transfer Case Range Position Sensor Circuit Performance) — The module’s detected an erratic signal from the transfer case gear position sensor.

C0642 or C0643 (Transfer Case Range Position Sensor 5V Reference Voltage Circuit 1) — The module’s detected an erratic 5V reference voltage on the gear position sensor circuit.

C0396 or C039E (Range Actuator Position Sensor Circuit) — The module’s detected an erratic voltage from the range actuator position sensor circuit.

P0652 or P0653 (Range Actuator Position Sensor 5V Reference Circuit 2) — The module’s detected an erratic voltage on the range actuator position sensor 5V reference circuit.

C0397 (Transfer Case Clutch Performance) — The module’s encountered a transfer case clutch problem, which could indicate excessive clutch pack wear, clutch calibration not learned, or a range position sensor out of range.

C0398 (Range Actuator Position Correlation) — The module’s detected a difference in the signals or erratic signals from the range actuator position sensor and the gear position sensor.

C0550 (Electronic Control Unit Malfunction) — The module’s detected an internal failure.

C0569 (System Configuration Error/Calibration Not Learned) — The range actuator relearn procedure wasn’t performed after replacing the module.

C0896 (Device/System Voltage) — The module’s detected the system voltage is out of range (10.5-18.5 DCV).

P0601, P0602, P0604, P0606, P062F, or P064F (Internal Control Module) — The module’s detected an internal failure.

P2160 or P2161 (Vehicle Speed Sensor 2) — The ECM’s detected an erratic VSS signal from the transfer case speed sensor circuit.

P279A, B, and C (Transfer Case/4WD Neutrals Range Performance) — The module’s detected an incorrect transfer case ratio. The module compares the transmission output speed sensor signal to the transfer case output speed sensor signal to calculate transfer case range.

Now that we’ve looked at the MP3010 transfer case system diagnostic codes, it’s time to see how to perform the reset and relearn procedure required to keep the system rolling down the road.

Reset and Relearn Procedure

Using a scan tool:

  1. Key on, engine off.
  2. Select Transfer Case Control Module.
  3. Select Module Setup.
  4. Select Range Actuator Learn Procedure.

When you initiate the Range Actuator Learn Procedure, you should hear the transfer case encoder motor engage, indicating that the Actuator Learn Procedure has been successful.

Using the transfer case shift control switch:

  1. Key in accessory position, engine off.
  2. Engage parking brake.
  3. Transmission in neutral.
  4. Turn transfer case shift control switch to the 2WD HI position for at least 5 seconds.
  5. Turn transfer case shift control switch clockwise past the 4WD HI position until it stops, and hold in this position for at least 30 seconds.

You should hear the transfer case encoder motor engage, indicating that the Actuator Learn Procedure has been successful.

Well, there you have it. We’ve taken a brief look at the MP3010 transfer case control system to keep it rolling down the road. With a better understanding of how the system operates, you should have no problem keeping those trannys rolling.