This is a common question on new Mercedes. If this doesn’t help the best thing to do is call the company that makes your garage door opener. The system is called HomeLink and it is the same system that is in all vehicles. They may know a trick!
Step 2 To program the system for the first time, press and hold the two outer buttons of the in-vehicle Mercedes garage door opener (A and C). Release the buttons only when the indicator light begins to flash. This should take approximately 20 seconds. (If you are programming the more than one garage door opener buttons do not perform this step — proceed to step 3.)
Step 3 Hold your hand-held remote control (E) approximately 2 to 5 inches away from the in-vehicle remote control buttons (A, B, C), keeping the indicator lamp (D) in view.
Step 4 Using both hands, simultaneously press and hold one of the in-vehicle buttons you wish to program (A or B or C), as well as the hand-held transmitter button (E). If the in-vehicle button has not previously been programmed, the indicator lamp (D) will begin to flash slowly. DO NOT release the buttons until the indicator lamp changes from a slow to a rapid flash. If the button has already been programmed, the indicator lamp will only start flashing after 20 seconds. To erase any previous programming start from Step 2.
Step 5 Press and hold the programmed button (A, B or C), and watch the indicator lamp (D). If the indicator lamp is solid, the button is programmed and your garage door should open when the programmed button is pressed and released.
If the indicator lamp blinks rapidly for 2 seconds and then turns solid, this means you have a rolling code system. If your garage door opener uses rolling code, please proceed with the instructions below.
Step 6 Locate the “training” button on the garage door opener’s motor head unit. Depending on the manufacturer of your garage door opener, the training button may also be called the “smart” or “learn” button. Press the “training” button. After pressing the button you have 30 seconds to start Step 7.
Step 7 Firmly press the programmed in-vehicle garage door opener button (A, B or C), hold for two seconds and release. Repeat the press/hold/release sequence up to three times to complete the programming.