I would explain it to you daughter that this is the way the "feature" works. The system was designed to work only on line-of-sight so that no one could intercept your code (unless you pointed it directly at them). With fresh batteries, mine works from about ten feet away. Ask her point the fob directly at the door handle from about ten feet away and give that a try.

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Michael

1988 300 SL (5 Speed)
1994 E320 Wagon
1997 C230