Transmission Adapt Function

Transmission Adapt Function





The 4T40-E uses a line pressure control system which has the ability to continuously adapt the system's line pressure (increase as needed) to compensate for normal wear of clutch fiber plates, seals, springs, etc. this "learning" feature is similar to what is used for fuel control (integrator/block learn) and throttle position (idle learn). The PCM maintains several adapt parameters for the transaxle:
- Upshift Adapt - The PCM monitors the Input Shaft Speed sensor and VSS during commanded shifts to determine if a shift is occurring too fast (harsh) or too slow (soft) and adjusts the transaxle pressure control solenoid signal to maintain a set shift feel.