Continental Automotive Technologies 5WY7635 Tire Pressure Unit User Manual Manual
Continental Automotive GmbH Tire Pressure Unit Manual
Manual
Annex No.5 
Technical Description 
Users Manual 
 5WY7635 

SIEMENS VDO Automotive    SV C BC P2 RF 
 IC:267T-5WY7635                            FCC ID:KR55WY7635 
I:\POSTZULA\Tpms_TG\TG1B-VL2\Technische_Dokumente\functionnal description_5WY7635.doc    1 of 4 
 User Manual / Functional Description 
 of the 
Siemens VDO 
 Tire Pressure Generation TG1B-VL2 wheel unit 
Type  
5WY7635 

SIEMENS VDO Automotive    SV C BC P2 RF 
 IC:267T-5WY7635                            FCC ID:KR55WY7635 
I:\POSTZULA\Tpms_TG\TG1B-VL2\Technische_Dokumente\functionnal description_5WY7635.doc    2 of 4 
1.1. SYSTEM OVERVIEW 
The TG1B-VL2 is a pressure sensor for Tire Pressure Monitoring System (TPMS) 
application. 
By several measurements and RF transmission, the driver is informed about the air 
pressure in his vehicle wheels. 
The following is a list of the wheel unit (WU) functions: 
• Pressure measurement 
• Temperature measurement 
• Motion measurement (centrifugal acceleration) 
• Battery status 
• Radio frequency RF emission 
• Low Frequency LF reception 
The system is made of an embedded WU that measures some parameters inside the 
tire and transmits them by RF at 315 MHz to a central unit (TGR) in the vehicle. In 
some cases, the TGR can trigger a RF emission from the WU by LF signal. 
LF triggering is made by some specific LF drivers and antennas. RF reception is 
made by one antenna linked to the TGR. LF triggering is only used in case of axle 
localization.  
The WU is mounted inside the wheels, fixed to the rim, which is also a part of the 
System. 
TGR
Aerial 
315 Mhz 
MHz
Aerial 
LF 
Wheel1 
WU1
Wheel2 
WU2
Wheel3 
WU3
Wheel4 
WU4

SIEMENS VDO Automotive    SV C BC P2 RF 
 IC:267T-5WY7635                            FCC ID:KR55WY7635 
I:\POSTZULA\Tpms_TG\TG1B-VL2\Technische_Dokumente\functionnal description_5WY7635.doc    3 of 4 
Rim WU
Tire
It is made of a PCB that supports the electronic hardware encapsulated inside a box 
and polyurethane foam. It is self-powered by a battery and includes all systems for 
measurements (pressure, temperature, centrifugal acceleration, and battery status), 
RF emission and LF reception. 
Theory of Operation 
The sensor function is to provide to the receiver by RF frames the state of pressure 
of the air in each one of the four tires of the car. The information given in the RF 
frame indicates exactly the state of the car (rotating wheel or not) and the state of the 
pressure in the tires. 
At any time, the sensor must be able to detect some changes of the wheel behavior. 
When the motion indicator is activated, the sensor enters the rotating mode. When 
the motion indicator is deactivated, the sensor enters the interim mode for maximum 
half an hour. During this period, the vehicle car return in rotating mode if it restarts 
before the end of the 30 minutes stopped period or after 30 minutes time in interim 
mode, the sensor goes automatically in stationary mode until it restarts and goes in 
rotating mode. 

SIEMENS VDO Automotive    SV C BC P2 RF 
 IC:267T-5WY7635                            FCC ID:KR55WY7635 
I:\POSTZULA\Tpms_TG\TG1B-VL2\Technische_Dokumente\functionnal description_5WY7635.doc    4 of 4 
1.2. BLOCK DIAGRAM 
The block diagram below shows the main electronic units of the wheel unit: 
1.3.  VARIANTS 
 Siemens type designation  Remarks 
5WY7635 Transmitter 315 MHz 
1.4. TYPICAL USAGE PATTERN 
One burst of 4 frames of 10.41ms per minute 
=> in one hour =4*0.0104*60=2.5 seconds of transmission duration. 
Transmitter ON    2.5    seconds / hour 
Transmitter OFF    3597.5    seconds / hour 
Duty Cycle: TON / T (ON+OFF) x 100% = 2.5 / 3600 x 100 % = 0.069 % 
Pressure, 
temperature, 
acceleration, 
Sensor and 
µcontroller 
RF emitter 
Lithium 
battery 
CR2450 
LF 
receiver 

SIEMENS VDO Automotive    SV C BC P2 RF 
 IC:267T-5WY7635                            FCC ID:KR55WY7635 
I:\POSTZULA\Tpms_TG\TG1B-VL2\Technische_Dokumente\functionnal description_5WY7635.doc    5 of 4 
1.5. TECHNICAL DESCRIPTION VARIANT 5WY7635 
Carrier Frequency  :  315 MHz 
Field strength   :  < 87 dBµV/m @ 3m (CW mode) 
Frequency shift  :  ± 35 kHz target value (± 30 kHz min to ± 50 kHz max) 
Number of channel  :  1 
Type of modulation  :  FSK-ASK 
Antenna    :  Integral 
Voltage supply  :  1 lithium battery 3V (CR2450) 
Voltage supply range :  2.1 up to 3.2 V 
1.6. LABEL DESIGN CANADA, USA, MEXICO 
Siemens VDO 
5WY7635 
FCC ID:KR55WY7635 
IC:267T-5WY7635 
owner manual: warning statement 
This device complies with part 15 of the FCC Rules and RSS-210. Operation is 
subject to the following two conditions: (1) This device may not cause harmful 
interference, and (2) this device must accept interference received, including 
interference that may cause undesired operation. 
Note: 
Changes or modifications not expressly approved by the manufacturer could void the 
user's authority to operate the equipment.