Notes on "6-Speed automatic transmission 09E"
992303The 2004 Audi A8L Technical Features contains information about the function of this transmission.
Transmission
- The 6-speed automatic transmission 09E all-wheel drive is equipped with 6 hydraulically activated forward gears. When the lock-up clutch is closed these forward gears bypass the torque converter slip and become mechanically driven gears.
- A special feature of the 09E transmission is the position of the front final drive (front axle differential with flange shafts) in front of the torque converter. This allows for a more even weight distribution between the front and rear axles on the vehicle.
Torque converter
The torque converter is equipped with a slip-controlled torque converter lock-up clutch. Due to the new construction of this transmission, this is located behind the front final drive.
Mechatronics unit
The mechatronics unit incorporates the hydraulic control, the Transmission Control Module (TCM) J217 , the Multi-Function Transmission Range (TR) Switch F125 and the sensors and actuators as a complete synchronized unit. The mechatronics unit is installed in the transmission within the oil pan.
Transmission Control Module (TCM) J217
The control module is a part of the mechatronics unit in the transmission.
Determining driving situation and driving resistance dependent shift point occurs automatically.
Advantages:
- It is shifted depending on consumption
- Maximum engine output is always available
- Individual adaptation of shift points in all driving situations
- Gear shift points are infinitely variable
Self-diagnosis
Before performing service work on the automatic transmission, cause of damage must be exactly determined via "Guided Fault Finding".
To perform "Guided Fault Finding".
Gear change point variations for gradients
An additional gear change map automatically selects gear changes for gradients dependent upon accelerator pedal position and driving speed.
- Gear change map for extreme uphill stretches is matched to engine output
- Gear change map for extreme downhill stretches is matched to the braking effect of the engine
- Direct gear selection by way of the Tiptronic function permits utilization of engine braking action with a specific gear engaged, e.g. on a downhill gradient with a trailer