Automatic Transmission/Transaxle: Description and Operation
General Information
General Repair Information
To ensure correct and successful transmission repairs, the greatest care and cleanliness, as well as the use of good and correct tools is essential. The basic rules for safety must be observed during repair work.
A number of generally valid instructions applicable for the various repair procedures, which were formerly repeated a number of times at numerous places in the workshop information, are summarized here. They apply to this workshop information.
Transmission
The 6-speed automatic transmission 09G has six hydraulically actuated forward gears. The 2nd, 3rd, 4th, 5th and 6th gears, when locked up, become mechanically driven gears by eliminating torque converter slip.
Torque Converter
The torque converter is equipped with a lock-up clutch. The lock-up clutch locks up depending on load and speed. The 2nd, 3rd, 4th, 5th and 6th gears can be driven mechanically (without slip).
Automatic Transmission Fluid
The ATF is filled for life. The ATF need not be changed during a service.
Use only ATF which has been ordered as a part from
The ATF levels in the planetary transmission and final drive are checked and topped off together.
Transmission Control Module J217 with Fuzzy Logic
The gear change points, which are dependent on the driving situation and driving resistance, are determined automatically.
Advantages:
• Gear changes are consumption orientated.
• Maximum engine output is always available.
• Individual adaptation of gear change points in all driving situations.
• Gear change points are infinitely variable.
Vehicle Control Modules
The installation locations of all vehicle control modules and other useful information can also be found in.
09G Transmission Information Sources
For information regarding the design and function of this transmission, refer to 851503 Automatic Transmission 09G.
Tools
A summary of the special tools and workshop equipment used in the workshop information precedes each repair procedure and can be found in " Special Tools".
Uncertainty often occurs with smaller bolts having low tightening forces. Torque wrench V.A.G 1783 can be used with these bolts.
Transmission
• If transmission covers have been removed or transmission has no fluid, do not run engine or tow vehicle.
• First thoroughly clean connecting points and surrounding areas and then loosen bolts.
• When installing the transmission, ensure that dowel sleeves between the engine and transmission are correctly located.
• Place removed parts on a clean surface. Cover parts to prevent soiling. Use plastic sheeting and paper. Use lint-free cloths only!
• Install only clean parts; do not remove new parts from packaging until immediately before installing.
• If repair work cannot be performed immediately, carefully cover or seal components.
• With transmission removed, secure torque converter against falling out.
Transmissions with and without filler tube
As of April 2006 the filler tube was eliminated.
Here is an example with a filler tube as it is installed in older transmissions. This tube has been discontinued.
This old filler opening with the red cap is not needed because ATF can be drained or filled as required through the bottom hole. The height of this tube determines the level of the ATF.
The tube must be removed to drain the fluid.
• After installation, check ATF level and top off --> [ ATF Level, Checking and Filling ] Service and Repair.
Gaskets, Seals, and Oil
• Always replace O-rings, seals and gaskets.
• Before installing a radial oil seal, coat sealing lips and area between these with sealing grease (G 052 128).
• Open side of oil seal faces oil.
• After installing, check ATF level.
CAUTION!
Be careful when working with oil. Dispose of drained oil according to regulations. Remember: one drop of oil will contaminate 1,000 liters of water.
Nuts and Bolts
• Loosen and tighten securing nuts and bolts for covers and housings diagonally.
• Torque settings are specified for unoiled bolts and nuts.
• Threads of bolts secured with locking fluid must be cleaned with a wire brush. Then insert bolts with locking fluid (AMV 185 100 A1).
• Use a thread chaser to clear residual locking fluid from all threaded holes into which self-locking bolts are to be installed. Otherwise there is a danger of bolts shearing when subsequently being removed.
• Always replace self-locking bolts and nuts.
Electrical Components
You have probably at some time received an electrical shock when touching a metal object. This is due to the electrostatic charge of the human body. This charge can disturb the function of electrical components of the transmission and of the selector mechanism.
- Before beginning work on electrical components, touch a grounded object, for example a water pipe or lifting platform. Do not touch connectors or open electronic components directly.
Guided Fault Finding, Vehicle Self-Diagnosis and Testing
Before making repairs to the automatic transmission, determine the cause of the fault as precisely as possible with the aid of "Guided Fault Finding".
Guided Fault Finding is carried out using vehicle diagnosis, testing and information system (VAS 5051B) --> [ Vehicle Diagnosis, Testing and Information System VAS 5051, Connecting ] Scan Tool Testing and Procedures.
The Guided Functions will guide you to the ATF temperature in shortest way possible --> [ Vehicle Diagnosis, Testing and Information System VAS 5051, Connecting ] Scan Tool Testing and Procedures.