Thread: Anyone with SLS & remote?

A test module was setup to try all duty cycles in 5% steps but it only caused slight shuffling movements of the suspension at 2 steps, indicating that the mechanism may work if the correct signal could be generated. A D2 owner with an oscilloscope has kindly monitored the RF receiver to BCU signal wire when the normal lock/unlock remote is used to gain insight into what the BCU to SLABS signal might be like. This has revealed that the signal is a high impedance 12V pulled low to create a coded pwm signal, not the other way round as I had assumed. The test module will be reworked to pull the signal low to create its signals rather than output a 5V or 12V pulse.

The RF receiver to BCU lock and unlock commands have a (rolling?) code component that the SLS remote would also have in order to confine the usage to a particular vehicle. The code segment does not conform to the stated 25 Hz pwm signal. The BCU likely removes the code segment from the message before sending it to SLABS but the commands may still not be simple pwm signals. The next test is a few weeks off yet but without a SLS remote to monitor, it will be the last unless a positive result is obtained.

Originally Posted by zzsteve

Is the RF signal sent on the same key fob carrier frequency of 433 MHz ?

Yes and its picked-up by the same RF receiver and sent to the BCU on the same wire and the BCU then sends SLS commands to SLABS (perhaps modified/simplified) if appropriate conditions are met. My idea was to send (wired from a module) appropriate signals directly to SLABS, bypassing the RF receiver and the BCU. If I can hit the jackpot then a cheap remote could be used instead of an on-off-on toggle switch.

Go Graeme!