You could also take a CAN-Device and look if the ECU ask for a code from the skreem (101#4144000000000000) and if the skreem answers (something like this: 111#03A0CFB400000000) and if the ECU accepts the code (101#4148000000000000). The CAN-Bus should be wired on the OBDII plug for a SRT.
Look at standard pinout of the OBDII or take bypass wires from the skreem module (the white 2 wire plug).
This CAN-Bus works with 500 kBaud.