09-16-2010, 02:55 PM
Officially Welcomed to the 'Fest
Join Date: May 2008
Mein Auto: 1997 Z3 1.9L DASC Auto
You don't need to flash a BMW transmission controller. I'll look into the code and post further. I would be more concerned about the power supply code. Check your battery and make sure it's up to snuff. A low battery/bad alternator can cause the transmission to go into fail safe mode.
If the fail safe code is temporary, shutting down the car for 2 minutes and restarting will clear the trans fail code and set the check engine light but the car will perform as normal. Is the car resetting after turning it off for 2 minutes?
Is this an "EH" version transmission? (look on the serial plate - will be in large block letters)
1993 740i Wiring Diagrams Link <--- Click Here - (best I can do)
According to the '93 wiring diagrams pins 87 (RX -receive) and 88 (TX - transmit) of the EGS (TCU) are the data link pins and 85 and 86 go to the DME with pin 84 going to the shield of 85 and 86. Pins 85 and 86 of the EGS go to the same pin (85 and 86) of the DME. I would do a continuity test between the EGS and DME pins.
CAN = Controller Area Network - two wire communication system between modules in the car
CAN Bus Information Link <--- Click Here
The CAN bus (controller area network) is a serial bus system, in which all connected stations are equally
entitled, i.e. each control unit can both send as well as receive. In other words, the connected control units
can 'communicate' and exchange oinrfmation via the lines. Due to the linear structure of the network, the
bus system is fully available for all other stations in the event of one failing. The connection consists of 2
data links (CAN_L and CAN_H) that are interference-protected by means of shielding (CAN_S). At present,
the AGS and DME control units are interconnected with this system. Linking in of further controls will follow.
The connected control units must have the same CAN status. The CAN status can be checked via the
diagnosis interface. The CAN status (bus index) is specified on the identification of the relevant control unit
connected to the CAN bus.
Following information can be interchanged via CAN with the adaptive electronic transmission controls EGS:
Terminal 15 (ignition ON)
Engine load signal
Engine torque reduction by ignition timing adjustment
Torque converter clutch opened or closed
Selected drive program
Current drive stage
Deceleration fuel cut-out active or not active.
Last edited by Monolith; 09-16-2010 at 03:36 PM.