1. Throttle Position Sensor (TPS):
- This sensor sits on the throttle body, directly measuring the throttle opening.
- It sends a signal to the transmission's Electronic Control Unit (ECU).
2. Electronic Control Unit (ECU):
- The ECU receives signals from the TPS and other sensors (like engine speed, transmission fluid temperature, etc.).
- It uses this data to determine the optimal shift points, torque converter lock-up, and other functions of the transmission.
3. Transmission Modulation:
- The ECU sends signals to the transmission's hydraulic control system.
- This system includes solenoids that modulate the flow of transmission fluid, which in turn controls clutch engagement and release.
How it Works:
- Throttle Opening: As you press the accelerator, the throttle opens, and the TPS sends a signal to the ECU.
- ECU Response: The ECU analyzes the signal and other sensor data to determine the appropriate transmission behavior.
- Hydraulic Control: The ECU then sends commands to the solenoids, which adjust the hydraulic pressure to engage or disengage clutches and shift gears.
In essence, the TH700R4 transmission uses the throttle position sensor and the ECU to indirectly control engine speed and power, rather than a dedicated "throttle valve" like in a carburetor.
Important Note: The term "throttle valve" is sometimes used loosely to refer to the throttle body itself, which houses the TPS and is responsible for controlling the amount of air entering the engine. However, it's crucial to differentiate this from the traditional throttle valve found in older carburetor-equipped vehicles.
