Comfortronic is an automatic transmission with a manual gear shifting function, installed on Lancia cars.
Comfortronic operating principle
The Comfortronic transmission is based on a classic automatic gearbox with a hydraulic torque converter, planetary gear sets, and electronic control. The manual mode uses specialised firmware. In order to activate it, the driver moves the gear lever into the corresponding position. Moving the lever towards “+” or “-” shifts gears up or down.
Popular Comfortronic transmissions
| Gearbox code | Manufacturer | Number of gears | Max torque, N·m | Max engine capacity, L | Car layout | Production start | Model applications |
| 4HP20 | ZF | 4 | 330 | 3.5 | FWD | 1995 | Lancia Kappa; Lancia Lybra; Lancia Phedra |
| AW55-50SN | Aisin | 5 | 330 | 3.5 | FWD | 2000 | Lancia Thesis |
Common malfunctions of Comfortronic transmissions
| Malfunctions | Transmissions |
| The transmission starts vibrating and leaking due to the torque converter friction plate wearing out. | ZF 4HP20 |
| The transmission pump parts such as the bush, the bearings of the stator and of the drive gear break down. | ZF 4HP20 |
| The solenoids break down often. Their breakage is usually caused by soiling. | ZF 4HP20; AW55-50SN |
| The gear position sensor has a short lifespan. | ZF 4HP20 |
| The bushes of the planetary gear sets are prone to premature breaking. | AW55-50SN |
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