In the frequency range of the transmitter key or KEYLESS-GO card, many other radio-operated systems also operate such as, radio frequency headphones, radio thermometer, garage door opener, alarm systems etc.
These transmitters operate with a much higher output as compared to the transmitter key or the KEYLESS-GO card. This could lead to severe malfunctions.
Due to the size of the key or the KEYLESS-GO card higher transmission power is not possible as the dimensions of both the transmission antenna and the batteries cannot be changed.
This means that, depending on the location of the vehicle, such strong disturbing influences may be present that unlocking or locking or engine start via the KEYLESS-GO is not possible at times.
Most of the vehicles mentioned above have an infrared transmitter in the transmitter key in addition to the radio remote control so that, in the event of malfunctions, unlocking or locking the door is possible at short distance using the transmitter key by means of the infrared signal.
Models 163, 168, 170, 638, 901, 902, 903, 904, 905 are not equipped with additional infrared function and - depending on the special equipment involved - nor are models 169, 414, 171, 245, 906.
In case of emergency, all vehicles can be opened or unopened using the emergency key.
In such cases a vehicle defect is not present. Please advise customer of this possibility.
Please observe the relevant notes in the operator's manual for vehicles with KEYLESS-GO card. It is recommended to always carry a key along so that the problems mentioned above can be ruled out.
Furthermore the possibility exists that selective locking of vehicles is prevented due to local use of radio interferers by people with a criminal background.
Please point out to the customer that they always have to make sure that the vehicle is locked. Only when the vehicle acknowledges the locking carried out by pressing of the transmitter key's lock button (with KEYLESS-GO the sensor area on the door handle) by flashing 3 times and all the locking pins are down, is the vehicle actually locked.