The mechanical components of this unit are as follows:
| • | A torque converter with a Torque Converter Clutch (TCC) |
| • | Intermediate/4th and Lo/Reverse friction band assemblies |
| • | Forward, Coast, 2nd, Reverse, and Direct multiple disc clutch
assemblies |
| • | Two planetary gear sets: Input and Reaction |
| • | Two roller clutches (Lo and 2nd) |
| • | One control valve assembly |
| • | A final drive and differential assembly |
The electrical components of this unit are as follows:
| • | Two shift solenoid valves, 1-2 and 2-3 |
| • | A Torque Converter Clutch Pulse Width Modulation (TCC PWM) solenoid
valve |
| • | A transmission Pressure Control (PC) solenoid valve |
| • | An Automatic Transmission Fluid Temperature (TFT) sensor |
| • | Two speed sensors: Input and Output Speed Sensor |
| • | An Automatic Transmission Fluid Pressure (TFP) Manual
Valve Position Switch assembly |
| • | An Automatic Transmission Wiring Harness Assembly |
Transmission Adapt Function
The 4T40-E transmission uses a line pressure control system, which has
the ability to continuously adapt the system's line pressure. This compensates
for normal wear of the following parts:
| • | The clutch fiber plates |
The PCM maintains the Upshift Adapt parameters for the transmission.
The PCM monitors the AT ISS sensor and the AT OSS during commanded shifts
in order to determine if a shift is occurring too fast or too slow. The
PCM adjusts the signal from the transmission pressure control solenoid in
order to maintain a set shift feel.
Transmission adapts must be reset whenever the transmission is overhauled
or replaced. In order to reset transmission adapts, select the following:
- Tech 2
- Special Functions
- Transmission Output Controls
- Clear TAPS
