Drivetrain Control Module - Operation

OPERATION

POWER UP/DOWN

The Drive Train Control Module (DTCM) will power up with an OFF/ON transition of the hardwired ignition switch input, or with the presence of active CAN C communications.

The DTCM will power down when the vehicle ignition switch transitions from ON to OFF, or there are no CAN C messages, or there are no system requirements that dictate the controller to remain active

START-UP DIAGNOSTICS

When the DTCM is activated, the internal circuitry will undergo a diagnostic procedure. The controller will examine all inputs and outputs for short circuits to ground, short circuits to battery and open circuits and will also verify proper CPU and memory operation. If a fault is detected, a message will be sent out over the CAN C bus to the Cluster based Electronic Vehicle Information Center EVIC indicating that service is recommended.

After passing all diagnostic tests, the controller will receive and process inputs and produce the appropriate outputs. Proper monitoring of the controller inputs and outputs performance will continue.

INPUTS/OUTPUTS

The following are inputs to the DTCM:

- Lateral Accelerometer
- Transfer Case Mode Sensor Signal
- 2 Direct Battery Feeds
- Ignition RUN Sense
- Sensor Grounds
- Module Grounds
- CAN C Bus

The following are outputs of the DTCM:

- 5V Sensor Supply
- Transfer Case Bi-directional Motor Control (A AND B)
- Switched B+ Solenoid Supply
- Transfer Case Motor Brake Control

TERRAIN SELECT SWITCH

The terrain select switch is used to communicate driver commands of various vehicle control systems related to vehicle ride height, traction, and stability control. The switch includes an Auto setting and a Neutral setting. The switch communicates with the Cabin Compartment Node (CCN) via a LIN Bus. The CCN sends information related to the terrain select switch via the CAN Interior bus.

TRANSFER CASE MODE SENSOR SIGNAL

The Transfer Case Mode Sensor Signal Input will provide the DTCM feedback about the position of the transfer case. The mode sensor will be a linear analog position sensor with a 1.4K +/- 20% potentiometer and a 1 K +/- 20% wiper resistor that converts the motor shaft position into a multiplexed voltage.

NEUTRAL LAMP

There will be a LED indicator in the Shifter bezel to indicate to the driver that the Transfer Case is in the Neutral gear. DTCM will be capable of driving the LED continuously at 25 mA.

TRANSFER CASE BI-DIRECTIONAL MOTOR CONTROL (A AND B)

This output will control a Bi-directional DC motor that controls a clutch pack in the Transfer Case that varies the torque transfer between the front and rear axles.

MODES OF OPERATION

Normal Operation

This mode is achieved by the ignition being switched in the RUN position, which powers up the 5V regulator and generates the appropriate RESET for the microprocessor. This mode also includes any required power-up system checks.

Shut Down Mode

This mode is activated when the ignition switch turned to the off position. The DTCM will perform any required Shut Down tasks prior to turning off the 5V regulator.

Limp-In Mode

This mode is entered when the DTCM has detected an error condition that prevents the system from performing its' required task. The DTCM operation will vary depending from modified operation to total system shut down based on the failure that has occurred.