The 4T45-E automatic transmission uses a line pressure control system, which has the ability to continuously adapt the system line pressure. This compensates for normal wear of the following parts:
| • | The clutch fiber plates |
| • | The seals |
| • | The springs |
The powertrain control module (PCM)/transmission control module (TCM) maintains the Upshift Adapt parameters for the transmission. The PCM/TCM monitors the input speed sensor (ISS) and the output speed sensor (OSS) during commanded shifts in order to determine if a shift is occurring too fast or too slow. The PCM/TCM adjusts the signal from the transmission pressure control (PC) solenoid in order to maintain a set shift feel.
Transmission adapts must be set again when the transmission is overhauled or replaced. In order to set the transmission adapts again, select the following:
- Scan Tool
- Transmission/Transaxle
- Special Functions
- Reset Transmission Adapts
