Continental Automotive Technologies A2C81494900 Radio Frequency Transmitter for RKE User Manual Functional Description
Continental Automotive GmbH Radio Frequency Transmitter for RKE Functional Description
User Manual

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 Functional Description / 
User Manual  
of 
Continental 
Remote Control System 
A2C81494900 

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General description of the RF transmitter 
The RF (radio frequency) remote control system consists of a RF transmitter and a RF 
receiver mounted within the control unit. 
The described system is a radio-frequency remote control for central doors locking / 
unlocking, trunk release and Panic activity  of an automotive vehicle.  
System Operation: 
Remote keyless entry function is provided by the RF system of the Rx and the RKE 
transmitter. The operation of these functions are as follows: 
Remote keyless Entry: 
The RKE transmitter operate at 315 MHz. ASK modulated data signal is transmitted to the 
Rx which receives the encrypted RF signal. Then, it send the data of the signal to 
corresponding the host Body control module through the communication line. This 
transmitter is used to transmit an information for locking or unlocking of the vehicle by an 
unidirectional RF transmission line for normal remote operation by pressing a button. 
In general the following functions are provided: 
-  Lock the car 
-  Unlock the car 
-  Unlock the trunk of the car 
-  Panic 
RF Key
Identifier
Start code
RF
emission
SRx
receiver
Host
BCM Communication
Line

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Typical usage pattern RKE transmitter 
30 lock / unlock operations in 24 hours with a typical transmission duration of  
270 milliseconds  1.25 lock / unlock operations / hour 
Transmitter ON  0.3375    seconds / hour 
Transmitter OFF  3,599.6625  seconds / hour 
Duty Cycle: TON / T (ON+OFF)  x 100% = 0.3375 / 3,600 x 100 % = 0,009 % 
The Modulation used is ASK Manchester coded , therefore  the  radiated energy during 
one telegram is  ON only a half of the time of the telegram this means and AVG factor of 
20Log(1/2)= -6dB 
Variants: 
Model 
Description 
A2C81494900 
Transmitter 4button ASK 315MHz 
Block diagram 

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Technical data transmitter 
Carrier frequency:    315.00MHz 150kHz  
Output power :    < 75.6dBuV/m @3m 
Modulation:    ASK 
Method of frequency generation:       SAW Resonator 
Number of channels:    1 
Supply voltage:    3 V 
Battery type:    lithium, CR 2025 
NOTE: 
Changes or modifications not expressly approved by the manufacturer could void the 
user´s authority to operate the equipment.  
This device complies with Part 15 of the FCC Rules. Operation is subject to the following 
two conditions: (1) this device may not cause harmful interference, and (2) this device 
must accept any interference received, including interference that may cause undesired 
operation 
Label design 
Continental 
A2C81494900 
FCC ID: KR5A2C81494900