Radio Frequency Remote Control - Range Information

Group 66
Electronic Transmitting/
Receiving Equipment

Bulletin Number
66 01 95 (4185)

Woodcliff Lake, NJ
April 1995
Product Engineering

SUBJECT:
Range of Radio-Frequency Remote Control

MODELS:
7 Series (E38)

SITUATION:
Three separate but related complaints may be encountered:

1. The central locking system cannot be activated from the distances quoted in the customer video and Owner's Manual (20 meters/65 feet). This 20 meter range can only be achieved under very favorable conditions.

2. The convenience opening feature can only be activated from a very short distance.

3. The convenience opening feature for the windows and/or sunroof is sometimes discontinued sporadically for no apparent reason and has to be restarted.

CAUSE:
For Points 1 and 2:

The information regarding the operating range contained in the Owner's Manual is misleading, as it applies only to optimal conditions.




Depending on where the transmitter is located in relation to the vehicle, the reception characteristics of the radio signals transmitted by the key will vary (refer to the illustration).

The operating range is influenced by external factors. It can be influenced positively (by reflections) or negatively (by interference), resulting in variations from the following average distances:

CENTRAL LOCKING/UNLOCKING:
approximately 15 meters (49 feet)

CONVENIENCE OPENING:
approximately 2 meters (6 feet)

For Point 3:
During convenience opening, even a momentary interruption of the continuous high-frequency signal from the transmitter to the receiver (caused by an external interference) will result in the convenience opening function being immediately shut off.

Many external sources of interference can cause this interruption, such as amateur radio, cordless or cellular telephones, radio-controlled model aircraft or cars, various remote controls, industrial systems, inadequately suppressed electric motors, etc.

CORRECTION:
For Points 1 and 2:

This information regarding the operating range contained in the Owner's Manual is being revised.

For Point 3:
If the convenience opening feature is interrupted, it can be restarted by pressing the "open" button again and holding it down.

Important Note:
Replacement of the control module or the transmitter batteries will not correct any of the above-mentioned complaints.

Please ensure that the customer is aware of this information before taking delivery of a new vehicle, or in the event of any of the above-mentioned complaints arising.

Warranty Status: Information only.