Brief description of AF30: Notes
The AF30 is an electronically-controlled 4-speed automatic transmission with a Lock-up function.
AF30 consists mainly of a 4-speed planetary gear unit, a torque converter with Lock-up clutch, a hydraulic control system and an electronic control system.
The gearbox is controlled by a control module (TCM), which continuously processes information from its own sensors as well as from other control modules. On the basis of this processed information, it controls the transmission hydraulic system.
Compared with conventional hydraulically-controlled transmissions, the AF30 has the following advantages:
- Improved shifting performance and smoother shifting as torque is reduced when shifting takes place.
- Reduced mechanical stresses on the entire drive train due to torque limitation.
- Improved fuel economy through a consumption optimizing driving program and Lock Up in 3rd and 4th gear. Under extreme driving conditions when adaptive shifting programs are active, it is possible to drive with Lock Up in 2nd gear instead of 3rd gear without Lock Up. Improved shifting functions that are selected automatically if the temperature of the transmission fluid rises have been introduced. See ADAPTIVE SHIFTING PROGRAMS .
- The possibility of selecting different driving programs: NORMAL, SPORT and WINTER.
- Self-diagnosis and storage of diagnostic trouble codes.
Compared with the earlier AF20/AF22 automatic transmissions, the AF30 incorporates the following modifications:
- The transmission casing, inner drive units and inboard drive-shaft universal joints are reinforced to withstand the higher torque developed (310 Nm).
- The TCM sends and receives information from the other control modules in the car through a bus communication system, see BUS COMMUNICATION .