Manual transmission with automatic shift control SMG Standard type GS6-37BZ E85 Introduction The concept of manual transmission SMG with automatic shift control came from motor racing and was put into series production during this period. Specifically, the SMG is capable of automatic clutch operation and gear changes, as opposed to a traditional manual transmission. The functions that were originally performed by the driver via the clutch pedal, shift lever and accelerator pedal when changing gears are now performed by an electro-hydraulic control system. The SMG can - Manual Sequential Shifting = Manual mode gears will be switched sequentially (in sequence) by pushing the "+/-" buttons. Quick, multiple taps can jump gears. Gear shifting takes place on the gear selector lever in the center console or on the 2 gearshift levers on the steering wheel. Gears can be switched manually at any speed or at any accelerator pedal position. The shift pulses are transmitted electronically to the SMG control unit. In this so-called "shift-by-wire" transmission, there is no mechanical connection between the gear selector or shift lever and the gearbox. - Automatic operation mode = driving mode The gear shifting process in automatic operation mode is automatically controlled according to the characteristic line or driving conditions. [System overview...] The SMG GS6S37BZ (H-SMG) is based on the 6-speed manual transmission GS6-37BZ (H transmission). Compared with traditional manual transmissions, the most fundamental advantages of SMG: - The clutch pedal is eliminated, because the clutch disengagement and engagement process is carried out automatically - 3 operating modes can be selected: ? Via shift lever or shift balance Sequential manual gear changes using the SPORT button? Dynamic Driving Control FDC using the SPORT button: sporty driving by intervening in the steering, engine and transmission controls (in manual mode = drive mode)? Drive mode = automatic mode - gear shifting sequence Short and precise, no shifting errors (shifting time of up to 0.15 seconds) - Safe and comfortable: Because the shift balancer is mounted on the steering wheel, both hands can remain on the steering wheel when changing gears. Date of entry into production: SMG offered as special equipment SA (SA 206). Model Engine Planned E85 M54B25 M54B30 April 2003 Short description of global components The SMG system consists of the following components: - Selector lever with selector mount and selector lever trim. Sequential shifting is possible by clicking on the selector lever. The selector lever has 6 positions: 3 spring-locked positions for neutral "N", reverse gear "R" and manual mode (icon "-" between neutral and drive) and 3 only The non-locking position of the push button ("+", "-", "D" (driving mode = automatic operating mode). In order to detect the position of the gear selector, 7 Hall sensors are installed in the gear selector base. There is also a selector lever locking element (self-locking function) installed in the gearbox. Lighted selector lever position indicator in the selector lever trim panel [more information...] - with gearshift balance. A steering wheel with a shift lever allows manual shifting without taking your hands off the steering wheel. Pull one or both shift levers to shift up, and press the rear gearbox to shift down [more info... ] - SPORT button for Dynamic Driving Control FDC The SPORT button can be used to activate Dynamic Driving Control FDC: the gearshift time is shortened and the gearshift characteristic line is more sporty. The engine responds instantly to the deflection force and the holding force on the steering wheel. This will be determined during movement. Dynamic Drive Control is always deactivated when the engine is started [more information...] - SMG Hydraulic Unit with Sensor Clutching and shifting are performed automatically with the help of the SMG hydraulic unit and sensors. More information...] ? Gearshift and selection angle actuator The gearshift and selection angle actuator pushes the gearshift shaft onto its shaft and rotates the gearshift shaft during gearshift slot changes.
[more information...] ? The shift path sensor and selector angle sensor detect the engaged gear via the shift path sensor and selector angle sensor: The shift path sensor detects the advance of the selector shaft in the respective shift gate. and backward movement. The selector angle sensor detects the rotation of the shift shaft and switches the shift gate. [More information...] ? Pressure Accumulator The pressure accumulator is installed on the lower left side of the gearbox to ensure sufficient oil pressure during shifting. The pressure accumulator is divided into 2 cavities by a piston. A cavity is filled with nitrogen at approximately 27 bar at -25°C. The second cavity receives oil from the hydraulic pump. Its storage volume is approximately 285 cm 3 . ? Pressure sensor The pressure sensor is mounted directly on the valve body and reports the current oil pressure to the SMG control unit. The hydraulic pump will turn on or off as needed. ? Clutch actuator with clutch stroke sensor The clutch actuator performs the clutch action. The separation stroke is detected by the clutch stroke sensor. [more information...] ? Hydraulic pump The hydraulic pump with electric motor is charged to a system pressure of up to 55 bar and is controlled by an SMG control unit. ? Transmission input speed sensor
Manual transmission SMG with automatic shift control Standard GS6-37BZ E85 BMW AG - TIS 04.06.2009 22:37
Version time (12/ 2007) Only available until the new DVD is published Copyright Page - 2 -
This sensor detects the gearbox input speed for comparison with the engine speed. After this comparison, the SMG control unit determines at what transmission speed the clutch can generate a flow of force between engine and gearbox. ? Reservoir tank The fluid reservoir ensures sufficient hydraulic oil is supplied to the system. Additionally, engine oil can expand in the reservoir. To check the oil level, there is also a maximum mark and - a minimum mark on the reservoir. A filter is also integrated in the reservoir to pre-filter the oil. ? The valve body has a solenoid valve, pressure sensor, pressure accumulator, one-way valve and micro filter. ? A total of 4 solenoid valves are installed on the solenoid valve body. Three solenoid valves control the clutch actuator and shift actuator during gear shifting. 1 solenoid valve controls the S-Cam brake (S-Cam= sleeve with S profile) as well as the gearshift and selector angle actuator for shifting the gearshift gate. Solenoid valves are also used as pressure relief valves in hydraulic systems. - SMG control unit The SMG control unit (GS30) calculates the control signals for the solenoid valves for the clutch process and gear change based on the sensor signals. In addition, the SMG control unit sends information to various control units, e.g. for adapting the engine speed, displaying the transmission program and displaying the selector lever position. [more information...] - Reversing light relay The reverse gearbox position signal is transmitted to the SMG control unit via the shift path sensor and selector angle sensor. The SMG control unit generates the signal for this relay. The reversing light relay is located in the electric control box cover. - Transmission SMG is based on the 6-speed manual transmission GS6-37BZ. The gearbox housing has been modified and a hydraulic unit and actuators for the clutch process and gearshift as well as other sensors have been installed. The gearshift lock and the selector lock on the shift shaft have been adjusted. The gearbox structure and clutch have not been modified. - Display in the instrument cluster The selected driving gear and transmission program are displayed in 2 sectors of the instrument cluster. In the event of a gearbox failure or operation in the emergency program, a warning light illuminates in the instrument cluster. [more information...] Auxiliary measured parameters for the following components: - Brake light switch The signal from the brake light switch is fed to the SMG control unit as an analog signal. For safety reasons, the brake light switch signal is transmitted from the DME control unit (Digital Engine Electronics) via PT-CAN (Powertrain CAN).
The signal from the brake light switch is used for the following processes: Release of the selector lever lock (gear locking function) Brake recognition When a gear jumps out when the engine is stationary - start inhibit and electronic start inhibit The anti-theft system (EWS) only switches on the starter motor after receiving the permission signal from the SMG control unit. The SMG control unit detects a start request via input terminal 50. The following conditions must be met in order to be allowed to start: ? The N position must be engaged (displayed as "N" on the instrument cluster). ? The SMG control unit allows starting and the clutch opens. - Electromechanical Power Steering EPS EPS An electromechanical power steering system with speed-dependent steering assistance. When Dynamic Drive Control is activated, the EPS control unit switches to a sporty characteristic line. At this time, greater fixing force and deflection force are required. The system function SMG contains the following functions:
Manual transmission SMG with automatic shift control Standard GS6-37BZ E85 BMW AG - TIS 04.06.2009 22:37
Version time (12 /2007) Only applicable until the publication of the new DVD. Copyright page - 3 -
- Engine starting - Gear shifting process - Driving in driving mode "D" with selector lever position (automatic operating mode) - Acceleration Assistance (race start function) - When exiting bad road conditions, e.g. from snow - When the vehicle is stationary - The gear selector is in the neutral position and the ignition is switched off - Fault display, SMG warning light and emergency procedure Engine start The gear selector must be turned on when starting the engine Shift the gear lever and gearbox into "N" (Neutral). In order to ensure that sufficient system pressure is available to open the clutch immediately after the engine is started, the SMG control unit is awakened through the basic module (GM) when the vehicle is unlocked. Calculate the storage pressure. When the storage pressure reaches the bottom, the hydraulic pump will run once. When the system pressure is reached, the hydraulic pump is switched off again by the SMG control unit. A "wake-up signal" is used to activate the selector lever position display in the center console. If terminal 15 is not activated after 15 minutes, the selector lever position display is switched off again. Shift process When the shift process is triggered in manual mode or driving mode, the SMG control unit will sequentially control the corresponding solenoid valves in the valve body. Pressurized hydraulic fluid flows into the clutch actuator and operates the clutch. At the same time, the SMG control unit sends a message to the DME control unit to start shifting gears and request a reduction in engine torque. The gear shifting and selection angle actuators are then controlled. The gearshift and selection angle actuator carries out the gearshift process and at the same time actuates the gearshift shaft to perform a forward or reverse movement, also turning the gearshift shaft when required. If necessary, the engine speed can be increased to support the shifting process (accelerate the engine during shifting). The clutch automatically closes after the gear is entered. The SMG control unit obtains the exact clutch position via a clutch travel sensor. The solenoid valve is de-energized after a gear change. The entire shifting process is related to the position of the pedal position sensor, driving speed, engine speed, transmission speed and other factors (such as oil temperature). Shortly before the vehicle comes to a stop, the SMG shifts into first gear and opens the clutch. The force transmission between engine and gearbox is interrupted. Gear shifting processes that would cause the engine speed to be too high or too low are prohibited. Driving in driving mode "D" (automatic operating mode)? The changing position of the cruise control pedal position sensor (accelerator press and release) is registered in the SMG control unit. The control unit prevents the resulting continuous switching between two adjacent gears (back and forth, e.g. constant speed change when driving on the motorway). ? Upshift suppression The SMG control unit detects a rapid reduction of the accelerator pedal via the accelerator pedal position sensor and activates the upshift suppression function. This prevents unintentional upshifts (for example before braking) and the engine acts as a brake. ? Driving uphill The SMG control unit detects uphill driving from the wheel speed sensor data and the accelerator pedal parameters and prevents (e.g. maintaining the same high engine speed and retracting the accelerator pedal) unintentional upshifts and frequent gear changes that can cause malfunctions .
? Driving downhill is detected by the SMG control unit program via the throttle potentiometer signal (engine load signal), wheel speed sensor signal (travel speed) and brake light switch signal (brake operation). In order to obtain and increase engine braking force, the SMG control unit shifts the vehicle into the next lower gear when driving speed increases. ? Braking delay and automatic retraction The SMG control unit detects braking delay via the brake light switch, wheel speed sensor and accelerator pedal parameters. The SMG control unit downshifts depending on the driving speed to obtain engine braking force. You can also jump several gears at this time. To accelerate again, the car will automatically shift into the correct gear. ? Manual driver intervention in automatic operating mode. SBT manual transmission with automatic shift control SMG standard GS6-37BZ E85 BMW AG - TIS 04.06.2009 22:37
Edition time (12/2007) Only applicable until the publication of the new DVD Copyright page - 4 -
If the driver operates the gear selector or shift lever in automatic operation mode, the vehicle will automatically switch to manual mode. The driver must reselect automatic operating mode. Acceleration Assist (Race Start Function) Prerequisites for the Acceleration Assist function: ? Rough road surface ? Off-state stability control DSC is off (press the DSC button for more than 3 seconds) ? SPORT button is pressed Acceleration Assist can optimize the vehicle from standstill to racing Horizontal acceleration. Engagement is usually completed at about 1300rpm. Acceleration assist brings the revs up to around 4000rpm before the SMG system closes the clutch. The driver only needs to press the accelerator pedal quickly and fully (kickdown function). A forced upshift in manual mode (only in the race start function) prevents the engine from reaching critical revs. The Race Start function can be deactivated by retracting the kickdown function using the accelerator pedal position, by issuing a manual gearshift command, deactivating Dynamic Drive Control FDC using the SPORT button, or inhibiting it by activating DSC. When emerging from adverse road conditions, such as snow, the selector lever can be quickly shifted from position 1. to position "R", or vice versa. The gear change must be completed within 0.8 seconds, otherwise the selector lever lock (shift locking function) will be activated. Vehicle at a standstill When the SMG control unit detects that the vehicle is at a standstill via the accelerator pedal position sensor, wheel speed and engine speed, it opens the clutch regardless of the driving program (manual mode or driving mode) and switches to gear 1. When the engine is running, if the driver's door is opened, it will remind you that a certain driving gear has been engaged (alarm signal 9 times). The icon N in the instrument cluster flashes (9 times). If neither the pedals, the shift lever nor the gear selector are actuated, the gear will be automatically exited after approximately 2 seconds. Selector lever position in neutral, ignition switched off If the selector lever is in neutral and the ignition switched off, the transmission program display icon "N" in the instrument cluster flashes. The serialized acoustic sensor in the instrument cluster is used to send out an alarm signal for about 9 seconds. The acoustic sensor is controlled by the SMG control unit. Fault display, SMG warning light and emergency procedures? The SMG warning light lights up and an alarm signal sounds. Correct the fault with substitute values ??in the SMG electronic control unit. This malfunction may affect shifting and ride quality. ? The driving program "D" will be displayed, the alarm light will light up, and the alarm signal will sound. SMG is an emergency program, which means limited shifting and driving quality. Upshifts can only be performed in 3rd gear at most, and the maximum driving speed is limited to about 80 km/h. ? Transmission failure "F" will be displayed, the warning light will light up, and an alarm signal will sound to remind the driver of a serious shift lever/transmission failure. The vehicle cannot be started again after it is stopped.
Maintenance Tips At the current position, the following maintenance tips are given:
General instructions: [More information...]
Diagnosis: ---
Coding/Programming: ---
Vehicle and key memory functions: --- National specifications
Manual transmission SMG with automatic shift control Standard version GS6-37BZ E85 BMW AG - TIS 04.06.2009 22:37
Edition time (12/2007) Only applicable until the new DVD is published Copyright page - 5 -
- USA Sports mode button (Special Equipment SA224 Dynamic Ride Control) is only available in the special equipment M Sports chassis (SA704) or SMG (SA 206). The possibility of typographical errors, omissions in content and technical changes reserved!