Fault in hand-held transmitter or vehicle

If the LED on the hand-held transmitter stays dark when the transmitter is operated, this is an indication of either an empty battery or a faulty hand-held transmitter.
Radio transmission is OK if the LED on the transmitter flashes when the transmitter is operated and the alarm readiness lamp on the dashboard flashes rapidly.

NOTE: If the alarm readiness light stays dark and chapters 1 to 4 can be excluded, the problem is a system fault of the vehicle!