Ahh...you ran into the same problem as me. The rolling code instructions are a bit tricky.

1. Program the homelink button with the garage door opener remote. (As if you did NOT have rolling code). This mean, hold the garage door opener close to the homelink unit, press the desired homelink button and the garage door opener button and hold until the homelink LED flashes rapidly
2. Now follow the rolling code instructions. I believe they are: press the "Learn" button on the garage door unit and then press the homelink button for 2-3 seconds. Repeat upto 3 times if necessary.

Try that.

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In the family: '03 E500 // '04 ML500 // 64 220SE