Transmission Control Module: Operation: Notes

The Transmission Control Module controls all electronic operations of the transmission. The Transmission Control Module receives information regarding vehicle operation from both direct and indirect inputs and selects the operational mode of the transmission. Direct inputs are hardwired to and used specifically by the Transmission Control Module. Indirect inputs originate from other components/modules and are shared with the Transmission Control Module via the vehicle Controller Area Network (CAN) bus.

Some examples of direct inputs  to the Transmission Control Module are:

1. Traction System Relay Output voltage
2. Trans Temp Sensor - P/N Switch
3. N2 and N3 Speed Sensors

Some examples of indirect inputs  to the Transmission Control Module are:

1. Controller Area Network (CAN) Bus Modules
2. Shift Lever Assembly
3. Brake Lamp Switch

Based on the information received from these various inputs, the Transmission Control Module determines the appropriate shift schedule and shift points, depending on the present operating conditions and driver demand. This is possible through the control of various direct and indirect outputs.

Some examples of Transmission Control Module direct outputs  are:

1. 1-2/4-5 Solenoid
2. 2-3 Solenoid
3. 3-4 Solenoid
4. TCC Solenoid
5. Modulation Pressure Solenoid
6. Shift Pressure Solenoid
7. DRB III(R) Scan Tool Communication
8. Sensor Supply Voltage
9. Solenoid Supply Voltage

Some examples of Transmission Control Module indirect outputs  are:

1. Transmission Temperature (to Powertrain Control Module)
2. Shift Lever Position (to Powertrain Control Module)

In addition to monitoring inputs and controlling outputs, the Transmission Control Module has other important responsibilities and functions:

1. Storing and selecting appropriate Shift Schedules
2. System self-diagnostics
3. Diagnostic capabilities (with DRB III(R) scan tool)