Subject: differences between EGS and AGS Author: shogun (moderator) : member since March, 2004 : 12552 posts Posted on: 2009-08-10 01:36:29

Transmission Systems
BMW uses automatic transmissions made by two different suppliers: GM and ZF.
• GM—Hydramatic is a manufacturing division of GM located in Strasbourg, France producing smaller transmissions used for lower output engines such as the M42 and M50.
• ZF—German company, “Zahnradfabrik Friedrichshafen” commonly known as ZF transmissions. ZF manufactures both manual and automatic transmissions. There are approximately 24 different control system versions. The transmission and control system technology becomes more sophisticated through the model years. The advancement is
mainly due to the integration of total vehicle system communications sharing information on a common communication bus (see “Testing Bus Systems” on page 52). This allows the transmission control module to read information from other controllers on the same vehicle, which
it uses for smoother and more efficient shift control regardless of the operating conditions.
BMW transmission control systems are listed as EGS or AGS.
• EGS is German for “Electronic Getriebesteuerung” or “Electronic Gearbox.”
• AGS is German for “Adaptive Getriebesteuerung” or “Adaptive Gearbox Control.”
Both EGS and AGS have different driver-selectable shift programs. However, AGS can automatically adapt and select the appropriate shift program depending on driving style or operating conditions. AGS has everything that EGS has plus the following:
• Shift points adapted to driving style
• No upshifting when driving in a curve
• Auto determination and selection of winter program to improve traction (2nd gear start-up)
• Stop and go traffic auto recognition, eliminating 1st gear for improved comfort
Both EGS and AGS have adaptive hydraulic pressure control. Transmission slip ratio (input speed to output speed) and slip time (amount of slippage during a shift) are monitored by the TCM. By
comparing target and actual slip, the TCM can adapt by modifying the pulse width modulation of the main pressure solenoid. This increases clutch apply pressures compensating for internal slip
resulting from clutch wear and optimizes shift performance.
ZF 4HP 22 EH
4-speed RWD
3 shift programs: Economy, Sport and Manual
TCM 35-pin
TCC On/Off
First electronic transmission in the U.S

That is what I found here
http://www1.snapon.com/display/DocMgmtDisplayFile.aspx?fileid=4653

But I am not familiar with the U.S. system, different introduction dates compared to Europe etc.


ABS and Traction Control Systems
BMW uses both Bosch and Teves ABS/Traction Control Systems. ABS and Traction Control are integrated into one control module (see Table 4-10 for different system descriptions). BMW calls traction control “ASC,” Automatic Slip or Stability Control. At speeds up to 24 MPH (39 KPH), braking individual rear wheels have the same traction effect as a limited slip differential. ASC came out in 1988 on the E31, E32, and E34. This early system used the ABS system to apply the rear wheel brakes to prevent wheel slippage. It is important to note that these early systems had no scan tool diagnostics (flash or blink code only). About 1990, ASC+T came out, adding traction control or engine power cutout to ASC. In addition
to using the ABS for ASC, this system had the ability to reduce engine torque to the rear wheels by either applying throttle valve control, retarding ignition timing, or shutting down fuel injection.
By the mid-1990s, more sophisticated systems phased out ignition and limited fuel injection control by integrating engine and transmission control, resulting in smoother operation, such as
preventing shifting during a traction control event. Next, additional traction control refinement resulted in MSR (Motor Speed Regulation) under deceleration. During deceleration, engine
braking under certain slippery conditions causes wheel slip. Traction control systems with MSR detect this condition and automatically increase engine speed until wheel slippage stops.
In approximately 1995, Dynamic Stability Control (DSC II) came out on the E31 and E38. DSC is an enhancement feature integrated into the ASC+T system. DSC provides additional stability during cornering and avoidance maneuvers as well as monitors steering angle, lateral
acceleration, brake pressure, and vehicle vertical axis movement. In addition to rear wheel control, a DSC system can also brake the front wheels to stabilize the vehicle. BMW uses both a Teves and Bosch DCS III system. In 1998, the E38 and E39 featured Bosch
DSC III version 5.3. Enhanced in 1999, Bosch version 5.7 came out with a new rotational rate/lateral acceleration sensor. The new 1999 E46 came out with Teves DSC III, which is similar in function to the Bosch DSC III. The E46 all-wheel drive uses Bosch DSC III 5.7. The E46 2-wheel drive uses Teves DSC III MK 60. Note that these systems have different components and operations.

Electronic Throttle Systems
There are three types of electronic throttle systems:
• EML
• MDK
• EDK
EML
EML is the electronic control module for throttle regulation and is available for selection on the
System Selection menu for some vehicles (see “Selecting a System” on page 9). There are two different EML systems:
• Bosch EML for M30, M70 and S70 engines
• EML IIIS for E38 (V12)
Bosch EML for M70 and S70 Engines
This is the first, full drive-by-wire electronic throttle system (used in U.S. only on the 7 and 8 Series). On the V12, a separate control module called EML synchronizes and controls dual throttle
valve assemblies called DKs. Whenever power has been disconnected or EML components have been replaced, the EML system usually requires adaptation to synchronize and coordinate system components. Use the
following throttle synchronization procedure for the M70 engine.

To synchronize the EML throttle:
1. Disconnect the battery for at least 1 hour.
2. Connect the battery and start the engine. Let the engine reach operating temperature without touching the accelerator pedal.
3. With the transmission in first gear, accelerate until engine speed is over 5000 RPM.
4. Release the accelerator pedal and coast until engine is at idle.
5. Repeat the above operation two consecutive times.

All Systems Fail-safe Emergency Operation
If a fault is detected, both the MIL and EML lamps may be illuminated. The system will initiate failsafe measures depending on the effect of the fault (increased airflow or decreased airflow). If
there is a fault in the idle speed actuator/circuit, the system will compensate to maintain idle. If the fault causes increased air flow (actuator failed open), then VANOS (variable valve timing) and
knock control are deactivated, noticeably reducing engine performance.
Emergency operation normally is divided into two modes of operation:
• Emergency Operation 1—This is when faults occur which do not impair actuator control, but do affect the system from functioning properly. For example, if one of the potentiometers fails,
the engine will slowly reach maximum speed with limited power (half throttle capacity).
• Emergency Operation 2—This is when faults occur which impair actuator control. Engine speed is limited to 1300 RPM and vehicle speed is limited to 20–25 MPH.

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Now I was carried away to much from the subject, but I just found this and wanted to save it.

E32 750iL 11/88, E32 750iL Highline 03/90
SHOGUN'S TRICKS AND TIPS FOR THE SEVEN SERIES

• 4hp24trans swap - larryrhr 2009-08-09 20:36:46 (70 views)
  • Can be done. Here's how to do it (url) - bcweir750 2009-08-09 21:04:02 (80 views)
    • this link does not answer his question - shogun 2009-08-09 23:29:33 (70 views)
      • US models got different switches. 91 is not a AGS - Johan750 2009-08-10 15:55:09 (67 views)
      • Whoops! Thank you Shogun! Please defer to Shogun's post (nt) - bcweir750 2009-08-10 01:06:20 (64 views)
        • differences between EGS and AGS - shogun 2009-08-10 01:36:29 (77 views)
          • Re: differences between EGS and AGS - larryrhr 2009-09-15 00:47:45 (1 views)