- 0xdurakiBMW GSM Phone System
The BMW E32 7 Series, and E34 5 Series, were in the selection of cellular provision via their GSM Phone/Telephone System. The GSM Phone interface contains 2-Pin Connector X18503 for the IBUS DAC/LAC general data connection to the Instrument Cluster/CCM/RDS Radio/OBC. The GSM Phone System is part of the CMT1000VR kit. The car GSM Phone/Telephone System uses older technology, which isn’t available anymore - the analog car phones do not work in most of the World, and haven’t been working for some time now. It might be possible to convert the GSM Phone System to digital GSM networks.
Some possibilities with modding this stuff is:
- Enabling the GSM Phone System to connect to GPSR/G3 networks
- Connecting the GSM Phone System to the Instrument Cluster OBC Display
- Wiring the GSM Phone System to newer mobile phones that support today networks
In BMW E34 Individual/Business version, some models included the FS. Euro Motorola GSM Phone alongside base. Check out the images below.
Alternative version was also included in some models of BMW E34 that uses newer Phone System (as used in BMW E38). Here is an example of that model:
More GSM Phone Versions are linked in images below:
Custom Standalone GSM Board
Standalone GSM Board
The use @okwestern (Ole Kristian Western) posted a thread on bimmerforums.com offering a service that will provide a standalone GSM board for the GSM Phone System included in various BMW vehicles to work with todays cellphone networks.
Cartel Telephones
A company named Cartel did make an old school looking car phone that was digital and has the looks of the older analog phones but, has the digital internals to work on the current digital networks or allows your current digital phone to connect through it via Bluetooth. I kick myself for not grabbing one back when they were available and can’t bring myself to pay the $400.00 price when they pop up on EBay every now and again. The BMW E34 model was labeled as Cartel CT-1000.
Tapping into the GSM Phone Keypad using MCU
The GSM Phone has a nice looking keypad. This introduces how to tap into the keyboard using a Microcontroller (MCU), to be able to send strings of numbers or similar. The MCU could then know which number is paired to which function, and therefore could control outputs, change settings and so on, all from the built-in GSM Phone system. There was an old blog post by James Holladay, but it seems like the images/videos aren’t hosted anymore.
Please visit the separate GitHub project titled Thesis on Reverse Engineering GSM Communication System Modules for BMW E34 Series 5 (1994) for more details.