Transmission Control Module (TCM)
The Transmission Control Module (TCM) controls the functions of this transmission. The TCM is part of a molded plastic leadframe module that is bolted to the mechatronic assembly. The leadframe 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).
| Item | Part Number | Description |
|---|---|---|
| 1 | - | Turbine Shaft Speed (TSS) sensor |
| 2 | - | Output Shaft Speed (OSS) sensor |
| 3 | - | Transmission Control Module (TCM) |
| 4 | - | Transmission Fluid Temperature (TFT) sensor |
| 5 | - | Transmission Range (TR) sensor |
| 6 | - | TCM transmission vehicle harness connector |
| 7 | - | Controller Area Network (CAN) + terminal |
| 8 | - | CAN - terminal |
| 9 | - | Reverse lamp relay power |
| 10 | - | PARK/NEUTRAL start enable signal terminal |
| 11 | 7G383 | Torque Converter Clutch (TCC) Variable Force Solenoid (VFS) |
| 12 | 7G484 | Shift Solenoid E (SSE) (ON/OFF) |
| 13 | 7G383 | Shift Solenoid D (SSD) VFS |
| 14 | 7G383 | Line Pressure Control (LPC) solenoid |
| 15 | 7G383 | Shift Solenoid C (SSC) VFS |
| 16 | 7G383 | Shift Solenoid B (SSB) VFS |
| 17 | 7G383 | Shift Solenoid A (SSA) VFS |
If the TCM detects a fault, it uses Failure Management and Effects Mode strategies to substitute a value or signal.
The TCM also uses Failure Management and Effects Mode strategies to compensate for detected solenoid or apply component faults that result in alternate shift patterns.
If the transmission loses complete electronic control, it will operate in a failsafe mode with:
- Maximum line pressure in all transmission ranges
- Functional PARK, REVERSE and NEUTRAL positions
- Operation in 3rd or 5th gear (depending on the failure conditions) when the selector lever is in the DRIVE, 3, 2 or 1 position
- TCC is released in all transmission ranges and gears
Solenoid Application Chart
| Gear | SS A (VFS1) Proportional | SS B (VFS2) Inversely Proportional | SS C (VFS3) Proportional | SS D (VFS4) Inversely Proportional | PC A (VFS5) Inversely Proportional | TCC (VFS6) Proportional | SS E (SS1) ON/OFF | ||
|---|---|---|---|---|---|---|---|---|---|
| Park | - | - | - | X | (1) | - | - | ||
| Reverse | - | X | - | X | (1) | - | - | ||
| Neutral | - | - | - | X | (1) | - | - | ||
| 1st Gear Manual | X | - | - | X | (1) | (1) | - | ||
| 2nd Gear Manual | X | - | X | - | (1) | (1) | - | ||
| 3rd Gear Manual | X | X | - | - | (1) | (1) | - | ||
| 1st Gear D | X | - | - | X | (1) | (1) | - | ||
| 2nd Gear D | X | - | X | - | (1) | (1) | - | ||
| 3rd Gear D | X | X | - | - | (1) | (1) | - | ||
| 4th Gear D | X | - | - | X | (1) | (1) | X | ||
| 5th Gear D | - | X | - | X | (1) | (1) | X | ||
| 6th Gear D | - | - | X | X | (1) | (1) | X | ||
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