Continental Automotive S120123007 Users manual

SIEMENS VDO Automotive SV C BC P2 RF

IC:267T-20123007 FCC ID:KR5S120123007

User Manual / Functional Description

of the

Siemens VDO

Tire Pressure Generation 1B-EP wheel unit

Type

S 120 123 007

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SIEMENS VDO Automotive SV C BC P2 RF

IC:267T-20123007 FCC ID:KR5S120123007

1. SYSTEM OVERVIEW

The tire pressure monitoring system (referred as TG for Tire Guard) consists of
the following units:

- Tire guard transmitter type S 120 123 007 which includes an integrated

pressure, temperature and acceleration sensor and a RF transmitter.

- RF receiver unit which includes a receiver (not described in this document)
The Tire Guard system monitors a vehicle's tire pressure whilst driving or

stationary. An electronic unit (wheel unit) inside each tire, mounted to the valve
stem, periodically measures the actual tire pressure. By means of RF
communication, this pressure information is transmitted to the RF
receiver/decoder.

In stationary mode, the pressure, temperature and acceleration are measured
about every minute and emission of RF frames occurs only if pressure variation,
higher than a threshold, is detected (leakage detection).

When the vehicle starts moving, the Tire Guard transmitter enters the driving
mode. Then the wheel unit measures and transmits data every minute. The
wheel unit will remain in driving mode for a period of 15 minutes after the vehicle
is stopped. After this period has elapsed, the wheel unit returns to stationary
mode.
If, during any measurement period in driving mode, the pressure leakage is
detected (difference compared to the last transmitted pressure value), a re­measure will occur after 1s (during 8s) taking in account the latest pressure value
emitted as reference value. If the pressure continues changing, an additional
transmission will be sent.

The circuit within the wheel unit monitors the battery every time a pressure
measurement is taken. A “Low Battery” function code will be sent when the
battery voltage within the wheel unit is below a pre-selected level.

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