Probably NOT the same as the e46. But it is easy to hardwire a vehicle like BMW or Mercedes without instructions, due to the overhead consoles having so many wires (meaning at least one of them has to be hot all the time) to tap in to.
Get you a circuit (light) tester and pull down the overhead area, turn the key to ACC, turn the headlights to OFF (not even Auto) and find you a hot wire and just tap right in.
Is the e90 factory pre-wired for the homelink garage door opener?
If so, wheterh or not you have the actual homelink unit, it would have a hot switched lead and a ground (as welll as a light lead which you won't need). On the e46 the homelink is in the sunroof access panel.
A forum community dedicated to BMW E46, E90, and F30 owners and enthusiasts. Come join the discussion about M performance, turbo kits, engine swaps, builds, modifications, classifieds, troubleshooting, maintenance, and more!