6.7 TPMS

6.7.1 Specifications
6.7.1.1 Fastener Tightening Specifications

Applications

Model

Specifications

Metric (Nm)

US English (lb-ft)

TPMS Module Bolts

M6 × 14

8-10

6.0-7.4

6.7.1.2 Sensor Specifications

Applications

Specifications

Weight

36-38 g

Shell Material

PBT +30% GF

Material

Polybutadiene

Put the valve rod into the mold for a second injection, final
assembly dimensions

Length: 72.2-73.2 mm (2.85-2.88 in)

Width: 36.3-37.3 mm (1.43-1.47 in)

Height: 24.8-25.8 mm (0.98-1.02 in)

Valve Material

Electric Aluminum

Installation Location

Inside tires, on the valve lip

Valve Nut Torque

8-10 Nm (6-7.4 lb-ft)

Working Voltage

Long-life (normal working life 5 years) 3 V battery

Brake System

TPMS

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6.7.2 Description and Operation
6.7.2.1  Tire  Pressure  Monitoring  System
Overview

In the current auto industry there are two kinds of tire pressure
monitoring system (TPMS): Direct and indirect. Direct TPMS
can detect the real pressure of automobile tires. Indirect TPMS
tires by checking out some of the technical parameters to infer
tire pressure. Direct TPMS tire pressure and temperature can
be accurately detected. TPMS is aimed at alerting the driver
when one or more tire pressure is below the warning pressure
level. Direct TPMS is divided into two types: high-end system
and low-end system. Low-end system will alert the driver when
the tire pressure is below the warning level, while the high-end
systems can not only alert the driver but also show which tire
tire  pressure  is  not  normal.  This  vehicle  TPMS  is  a  low-end
direct TPMS system provided by Lier Company.

6.7.2.2  The  Composition  Of  Tire  Pressure
Monitoring System

TPMS system is composed of the following components

–

TPMS Control Unit

–

TPMS  Sensors  (one  for  each  wheel)  (does  not  include
spare tire)

–

TPMS tire pressure management system and the TREAD
tire pressure warning indicator lights

TPMS Control Unit

Note

Tire  Pressure  Monitoring  System  receiver  can  provide
excellent installation flexibility to meet a broader range
of installation requirements. This flexibility of installation
can be achieved by the metal bracket connected to the
shell.  Bracket  connection  with  the  shell  allows  the
bracket to pass through the shell side and to be locked
without the use of additional fixtures.

When the vehicle ignition circuit is connected, TPMS control
unit micro-control unit and the RF receiver circuit are activated.
The  control  unit  continuously  monitors  the  TPMS  sensors
wireless signals. TPMS receiver unit can store TPMS sensor
id code (identification code, differentiate each sensor). When
the TPMS receiver unit receives a signal, it will check whether
the received information contained id code is consistent with
the stored id code. If they match, TPMS receiver unit will input
the information to the TPMS alarm algorithm. This algorithm
will evaluate each tire pressure and temperature changes over

time, and make a decision on the potential danger caused by
tire  deflation,  remind  the  driver  through  the  tire  pressure
(TREAD)  warning  lamp.  In  addition  to  handling  the  TPMS
sensors signals, TPMS control unit can also conduct its own
self-test on its circuit and working status. If a fault is detected,
TPMS control unit will continue to light the TPMS malfunction
warning lamp, to remind the driver.

TPMS Sensor

Each tire is equipped with a TPMS sensor, through the valve
installed on the wheel rim. TPMS sensor is a battery powered
component, regularly measures the tire pressure, temperature
and  acceleration  information.  Pressure,  temperature  and
acceleration information will be converted by the TPMS sensor
unit  micro-control  unit  into  a  digital  form.  Acceleration
information  is  used  to  determine  whether  the  vehicle  is
stationary  or  moving.  TPMS  sensor  is  equipped  with  radio-
frequency  transmitting  circuit  for  periodically  sending
information to the TPMS control unit.

Tire  Pressure  Management  System  Indicator
(TPMS)  and  Tire  Pressure  Warning  Lamp
(TREAD)

TPMS control unit can provide two consecutive current drive
capability of 200 mA, respectively, to drive two warning lamps.
When the tire pressure drops below a warning level pressure,
TPMS receiver will continuously light the TREAD warning lamp
to  remind  the  driver.  Throughout  the  course  of  the  ignition
cycle, TREAD alarm indicator status will be maintained. When
the TPMS is faulty, TPMS receiver unit will continuously light
the Tire Pressure Management System (TPMS) warning lamp.
TPMS receiver unit has a self-diagnostic function, its features
include:  warning  lamp  diagnostic  tests,  EEPROM  data
accuracy check, vehicle power supply voltage measurement,
warning lamp circuit failure, TPMS sensors low voltage status
monitoring,  TPMS  sensor  fault  condition  monitoring,  TPMS
sensor learn mode, the installation of not monitored tire.

When the tire low voltage alarm and system failures arise at
the same time, the tire low voltage alarm has a higher priority.

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TPMS

Brake System

6.7.3 System Working Principle
6.7.3.1 System Working Principle

TMPS Function Description

1. Reset

During the initial power-up or the voltage is below the reset
threshold, TPMS control unit will be in a non-operational
services status, in reset status. Once the voltage reaches
an  acceptable  value,  TPMS  control  unit  will  be  released
from  the  reset  status,  the  module  will  enter  the  normal
status.

2. Initialization Mode (System Self-test)

When the ignition is turned to ON, the initialization starts.
The  system  will  initialize  I  /  O  ports,  registers,  internal
variables, data storage address.

3. Start Mode

In the start mode, TPMS supports systems running:

a. Receive WE Sensors RF Data Frame

TPMS control unit continuously receives and deals with
TPMS sensors RF data frame.

b. Verify Sensor Received WE Frame Data

Upon  receiving  a  radio  frequency  emitted  by  the  WE
sensor data frame, TPMS control unit will firstly verify
the  legitimacy  of  the  message  received.  Sensor
information  will  be  sent  through  an  early  warning
algorithms for processing.

c. Process Each Received Valid TPMS Sensor Message

Once  a  low  tire  pressure  is  detected,  tire  pressure
warning lamp will be lit (TREAD).

d. Continuously Monitors The K-Bus Request

TPMS control unit must be activated prior to use of the
K-bus.

e. Vehicle Moving (Wheel Speed Sensor)

Monitor whether there is a tire without speed sensor or
the spare tire is used on the vehicle.

4. Diagnostic Mode

When connecting scan tool to communicate through the K-
bus, TPMS control unit enters into the diagnostic mode.

5. Sleep Mode

When the system enters into sleep mode, it will enter a low
power consumption mode. When entering sleep mode, it
does  not  receive  and  process  sensor  information,  or  the

diagnosis command, until the ignition is detected turned on,
the system exits sleep mode.

–

Wake-up Condition

When the ignition input signal changes from the ignition
off (OFF) to ignition on (ON), the TPMS control unit exits
sleep mode.

–

Sleep Condition

When  the  TPMS  control  unit  detects  that  the  ignition
input information is off (OFF) and no pending received
RF information, TPMS control unit will enter into sleep
mode.

Brake System

TPMS

6-103

6.7.4 Component Locator
6.7.4.1 Component Locator

1

2

FE06-1006b

Legend

1. TPMS Control Module

2. TPMS Sensor

6-104

TPMS

Brake System