If DSMLink v2 has a Shift CEL available, then you should be able to simply tap that wire at the ECU, and use it to trigger a low current 12 volt relay, which in turn would trigger the solenoid. The ECU switches the CEL to ground through the 3.3 ohm resistor, if I recall, so you just need to connect one side of the relay coil to +12 volts, the other relay coil contact to the CEL wire, the relay COMMON contact to GROUND, and the NORMALLY OPEN relay contact to the ground side of the solenoid you are using. Or, if the solenoid isn't plugged into the factory harness, you can connect the COMMON to +12 volts so it connects 12 volts to the solenoid when energized, and the other side of the solenoid to ground.