System Diagram: Notes
Network Message Chart
| Broadcast Message | Originating Module | Message Purpose |
|---|---|---|
| Engine Speed | PCM | Directly affects shift scheduling, TCC control, line pressure and transmission diagnostics. Indirectly affects shift pressure control. |
| Engine torque estimate | PCM | Directly affects shift pressure control, TCC control and transmission diagnostics. Indirectly affects shift scheduling and TCC scheduling. |
| APP | PCM | Directly affects shift scheduling, TCC scheduling and transmission diagnostics. Indirectly affects TCC control and shift control. |
| Commanded engine torque | PCM | Directly affects shift scheduling, TCC scheduling and transmission diagnostics. Indirectly affects shift control. |
| BPP | PCM | Directly affects shift scheduling and TCC scheduling |
System Operation
The PCM and its input/output network controls the following operations:
Shift timing
Line pressure (shift feel)
The transmission control strategy is separate from the engine control strategy in the PCM, although some of the input signals are shared. When determining the best operating strategy for transmission operation, the PCM uses input information from engine and driver related sensors and switches.
In addition, the PCM receives input signals from transmission related sensors and switches. The PCM uses these signals when determining transmission operating strategy.
Using all of these input signals, the PCM can determine when the time and conditions are right for a shift or when to apply or release the TCC. It also determines the best line pressure to optimize shift engagement feel. To accomplish this, the PCM uses output solenoids to control transmission operation.