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Originally Posted by Aus335iguy
Working m drive..........spill it ! What was the trick ?
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My ///M button on my steering wheel is only working with the same functionality as it does on the 1M, not like the E9x M3 (i.e. engages ///M drive). But at least I sorted my DTC and "DSC off" issue after retrofitting that M3 DSC module, and I also managed to get the cruise control working again.
On the 1M's, the ///M button on the steering wheel doesn't engage ///M Drive like it does on the M3, instead it provides a sharper throttle response. Here's a handy screenshot explaining the difference.
Regarding the ///M Drive and MDM (M Dynamic Mode) functionalities, these are predominantly controlled by the DME. It’s up to the DME to forward the signal to the DSC and JBBF (to control Servotronic) or not, once you press that ///M button on the steering wheel. For example the IJE0S N54 ROM just ignores the ///M button signal completely and the button doesn’t do anything. The MSS60 DME in the M3 forwards the signal to JBBF and DSC, and enganges ///M Drive.
The ///M Drive presets are actually saved directly in the DME memory, and the when ///M button is pressed, the DME recalls the saved presets, and sends the correct signals to the DSC and JBBF. For example if you have “SPORT” steering selected in iDrive (heavy weight steering), the DME will have this stored in its memory and it will send a signal to the JBBF asking it to apply heavy steering weight. The JBBF will then close the solenoid valve on the M3 rack, which restricts the flow of hydraulic fluid, and provides heavier steering, same applies to how the DME calls the DSC to activate MDM or turn off DSC completely based on what preset is selected in the iDrive and saved in the DME memory... etc.
There are tables in the DME 1M ROM to control the functionality of the ///M button (very basic compared to the M3, just applies a more sensitive accelerator pedal). The MSS60 DME in the M3 also has tables to control the ///M Drive and MDM (///M Dynamic Mode) functionality.
The tables are found in different memory locations in both DME’s, as they’re completely two different ECUs. We can potentially copy the ///M Drive functionality tables from the MSS60 to the 1KM0S ROM, and achieve the same ///M Drive and MDM functionalities as the M3. This is quite an involving and time consuming task to look up all the required tables, it's on my list, but not sure when I'll get around to do it tbh. Car is running flawlessly as is now
Also, if you haven't bought a M3 DSC yet, I can now custom flash the M3 DSC software on the standard 335i DSC, good if you'd like to attempt retrofitting for the DCT Drivelogic. All the memory locations across the DSC modules are identical, so you can flash any DSC software from any car on this platform to any DSC module you got on your hands. Keep in my mind that the modules are not physically identical though, M3 DSC have a stronger hydraulic ABS pump to provide more braking force to the larger calipers and tires. Kinda of expected really, the M3 has wider tires and wheels with more grip, you definitely need a more powerful ABS bump to pressurise the brake lines and apply enough brake force to the caliper pistons.
Would be nice to be able to store your favourite setting on the iDrive and call them whenever you need with the press of a button on the steering wheel
, I'll look into it in the future when time permits.
