This comprehensive 68-page PDF file contains the official VAG Self-Study Program 457 (SSP 457), focused entirely on the advanced power transmission systems introduced in the 2010 Audi A8 (D4 generation). To meet the demand for greater fuel efficiency without sacrificing premium performance, Audi partnered with ZF to develop an entirely new generation of 8-speed torque-converter automatic transmissions—the 0BK and 0BL. These gearboxes drastically reduced drag losses and allowed for the first implementation of a Start-Stop system in conjunction with a V6 TDI automatic. This technical training manual is an absolute must-have for VAG transmission specialists, diagnostic technicians, and Audi enthusiasts.
Please note: As a Self-Study Program, this document focuses on engineering design, electrical integration, and operational theory. It is not a step-by-step rebuild or workshop manual, though the foundational knowledge it provides is crucial for diagnosing complex transmission faults.
This detailed technical training manual covers the following key engineering topics:
- Shift-By-Wire Control System: A complete breakdown of the electronic gear selection system. It explains the operation of the “yacht-style” selector lever, the electronic sensors (G727) involved, the Auto P function (automatic parking lock), and the physical emergency release device.
- Eight-Speed Automatic Gearboxes (0BK/0BL): The core of the manual. It provides a deep dive into the mechanical layout of the ZF 8HP architecture, detailing the four planetary gearsets, the five shift elements (three clutches, two brakes), and how they interact to achieve eight forward gears with minimal drag.
- Hydraulics, Mechatronics, and Oil Circuits: Essential reading for transmission servicing. It meticulously maps out the separate oil circuits (gear oil and ATF), the twin-stroke vane ATF pump, and the complex Mechatronics unit that controls shift pressures. It also covers the Innovative Thermal Management (ITM) system that heats or cools the gearbox fluid via the engine’s cooling circuit.
- Advanced Control Functions: An overview of how the gearbox control unit (J217) integrates with the vehicle. It explains “neutral idle control” (which decouples the engine when stationary to save fuel), the Hydraulic Impulse Storage (HIS) required to keep the transmission primed during Start-Stop events, and how the gearbox utilizes navigation data to anticipate shifts.
- The Sport Differential: A dedicated section explaining the active rear axle drives (0BE/0BF), detailing how they intelligently distribute torque vectoring across the rear wheels to enhance cornering dynamics.
Whether you are trying to understand the exact actuation of the shift-by-wire parking lock, diagnosing a Mechatronics fault, or simply want to appreciate the engineering behind ZF’s legendary 8-speed automatic, SSP 457 is the definitive technical resource.
CONTENTS
- Power transmission in the Audi A8 ’10
- New features at a glance
- shift-by-wire shift control system
- Introduction
- tiptronic function
- Features of the shift control system
- Operating concept
- Shift schematic – function
- Selector lever sensors control unit J587
- Selector lever position sensor G727
- Functions, networking and interfaces
- Gear knob/selector lever release button E681
- Selector lever position indicator unit Y26
- Function diagram – selector lever E313
- Gearshift indicators
- shift-by-wire functions/operation
- Auto P function (automatic parking lock)
- Emergency release device for the parking lock
- Eight-speed automatic gearbox 0BK/0BL
- Introduction
- Specifications
- Special and common features at a glance
- Splined prop shaft
- Centre differential
- Torque converter
- ATF supply/ATF pump
- ATF (Automatic Transmission Fluid)
- Planetary gearbox
- Shift elements
- Brakes
- Clutches
- Shift schematic/shift matrix
- Description of gears – torque characteristic
- Sectional view of 0BK gearbox
- Oil system/lubrication/sealing of 0BK gearbox
- Separate oil systems
- Common oil system
- Oil system/lubrication/sealing of 0BL gearbox
- Gear oil system (common oil system)
- Common oil system – gear oil circuit
- Innovative Thermal Management (ITM)
- Gearbox heating/cooling – V8 FSI engine
- Gearbox heating/cooling – V8 TDI engine
- Mechatronics – electro-hydraulic control system
- Mechatronics/automatic gearbox control unit J217
- Mechatronics – actuators
- Pressure regulating valves – solenoid valves
- Hydraulic interfaces
- Monitoring of temperature in J217
- Mechatronics – sensors
- Gearbox input speed sender G182
- Gearbox output speed sender G195
- Parking lock
- Parking lock – function
- Parking lock – limp-home functions
- Parking lock sender G747
- Functions – neutral idle
- Functions – gearbox adaption
- Functions – start-stop system
- Hydraulic Impulse Storage – HIS
- Start-stop mode
- Functions – navigation-based gear selection
- Functions – displays/warnings
- Functions – special feature of adaptive cruise control (ACC) mode
- Functions – encoding the automatic gearbox control unit J217
- Functions – adapting the gear indicator
- Functions – limp-home programs and substitute programs
- Towing
- Rear axle drive 0BC/0BF/0BE
- Conventional rear axle drive/sport differential
- Rear axle drive 0BE/sport differential
- Intelligent torque distribution
- Self-Study Programmes relevant to the Audi A8 ’10
Eight-speed automatic gearboxes 0BK and 0BL belong to the category of conventional multistep torque converter automatic gearboxes.
They have many design and functional features in common with the six-speed automatic gearboxes described in Self-Study Programmes 283, 284 and 385.
These SSPs represent, as it were, the basis for SSP 457. Hence where the technology is identical, reference is made to SSPs 283, 284 and 385. It is, therefore, advisable to have all three booklets ready to hand.
Language: English
Format: PDF
Pages: 68
