Transmission Control Module (TCM): Notes

The Transmission Control Module (TCM) controls the functions of this transmission. The TCM  is part of a molded plastic lead frame module that is bolted to the mechatronic assembly. The lead frame module also has the Turbine Shaft Speed (TSS) sensor, Output Shaft Speed (OSS) sensor, Transmission Range (TR) sensor and Transmission Fluid Temperature (TFT) sensor integrated into it.

The TCM  responds to inputs from the sensors and from the vehicle Controller Area Network (CAN) signal. The TCM  uses the inputs to control the line pressure, shift and TCC  solenoids. The TCM  also provides power and ground for the reverse lamp relay coil and provides a PARK/NEUTRAL start enable signal.

The TCM  uses the following input from the vehicle CAN signal:

• Engine speed
• Engine torque
• Engine Coolant Temperature (ECT)
• Engine Oil Temperature (EOT)
• Throttle Position (TP)
• Accelerator Pedal Position (APP)
• Brake Pedal Position (BPP)
• ABS wheel speed
• Automatic Traction Control (ATC) status
• Four-Wheel Drive (4WD) status

The TCM  also:

• monitors inputs and outputs for the presence of faults.
• stores DTCs related to detected faults.
• supplies output to the vehicle CAN  for TR  position, OSS  , TSS  , TFT  , current gear and A/C inhibit.
• provides On-Board Diagnostic (OBD) information using the CAN  signal to illuminate the Malfunction Indicator Lamp (MIL) or Transmission Control Indicator Lamp (TCIL).
• displays diagnostic information to a scan tool through the Data Link Connector (DLC).