11.17 Data Communication System

11.17.1 Specifications
11.17.1.1 Fastener Tightening Specifications

Applications

Model

Specifications

Metric (Nm)

US English (lb-ft)

ECM Retaining Bolts

M6 × 18

8-10

6-7

ECM Bracket Retaining Bolts

M6 × 16

8-10

6-7

ABS Retaining Bolts

M8 × 20

35

26

airbag control module Bracket Retaining Nuts

M6

8-10

6-7

BCM Bracket Retaining Nuts

M8

8-10

6-7

Instrument Cluster Self-Tapping Screws

ST4.8 × 13

3-4

2-3

Air-Conditioning Self-Tapping Screws

ST6.3 × 19

5-7

4-5

Air-Conditioning Retaining Nuts

M6

5-7

4-5

IMMO Bracket Retaining Nuts

M6

8-10

6-7

TPMS Retaining Bolts

M6 × 16

8-10

6-7

Body Electric

Data Communication System

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11.17.2 Description and Operation
11.17.2.1 System Working Principle

Overview

This vehicle uses three types data communication:

–

CAN Bus

–

K Bus

–

LIN Bus

CAN Bus Description

–

CAN is the Controller Area Network acronym, stands for
Controller Area Network bus, the control devices connected
to each other and exchange data .

CAN bus communication medium is a twisted-pair, in which
high-speed  CAN  bus  communication  speed  is  500  kbps.
Twisted-pair terminals are two 120 Ω resistors, one end is
in the engine control module (ECM), the other side is in the
body  control  module  (BCM).  High-speed  CAN  bus  is  a
differential bus. High-speed CAN bus serial data bus (H)
and  high-speed  CAN  bus  serial  data  bus  (L)  from  a
stationary or idle-level drive to the opposite limit. About 2.5
V idle level is considered to transmit data and interpreted
as a hidden logic 1. The extreme limit of line-driven, high-
speed CAN bus serial data bus (H) would increase the 1V
and the high-speed CAN bus serial data bus (L) will reduce
1 V. Limit voltage difference 2 V is considered dominant
transmission of data and explain the logic 0 (as shown).

FE11-1504b

–

If the communication signal is lost, the program will target
the control module losing communication to set DTC codes.
The fault diagnosis codes can be read by scan tool.

Note

Serial  data  loss  does  not  mean  that  the  module  is
faulty.

–

The advantages of CAN bus:

1. Reduce the number of sensors and signal wires.

2. Reduce the number of wires in wiring harness.

3. Greatly reduces the weight of the wire harness.

4. Reduce the number of control devices pins.

5. Improve the reliability and durability.

–

In  this  vehicle,  high-speed  CAN  bus  allows  BCM,  ECM,
ABS, airbag control module, IP Cluster communication.

LIN Bus Description

–

LIN  is  used  for  automotive  distributed  electronic  control
system and is a new type of low-cost serial communication
system,  mainly  for  smart  sensors  and  actuators  serial
communication.

–

LIN bus features:

Based on UART data format
Single-master multi-structural
Single transmission :0-12 V
Communication speed: 19.2 kbps

K Bus Description

–

K bus is for communication between the vehicle ECM and
the external test equipment. Transfer rate is 10.47 kbps.
Voltage is between 0 V and 12 V: 12 V, logic "1"; 0 V, logic
"0".

Data Link Connector Description

Datalink connector (DLC) is the result of consultation between
automotive manufacturers and regulations. scan tool must be
used  to  communicate  with  the  vehicle  and  for  vehicle
communication system programming.

The connector must meet the following conditions:

–

Connect all scan tools 16-pin connector.

–

Always use No.16-pin to provide power to scan tool.

–

Always use No.4-pin as the scan tool ground.

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Data Communication System

Body Electric

–

The rest pins are for vehicle serial data communications.
The  vehicle  is  controlled  by  a  microprocessor,  which
communicates to scan tool through the serial data circuit.

Body Electric

Data Communication System

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11.17.3 System Working Principle
11.17.3.1 System Working Principle

Data Communication System Components

Use  scan  tool  to  access  the  following  control  module  data
circuits:

–

ECM

–

ABS

–

TPMS

–

IP Cluster

–

IMMO

–

ACU

–

BCM

–

HVAC

LIN Bus Applications

The vehicle with express window down function is equipped
with a LIN bus, connecting BCM and windows regulators, to
achieve power windows remote control and express window
down function. Refer to 

11.5.2.1

 

Description and Operation

.

K Bus Applications

This vehicle uses the K-bus to achieve the ECM, ABS, TPMS,
IMMO, and HVAC fault diagnosis.

CAN Bus Applications

In this vehicle, ABS, airbag control module, BCM, ECM, and IP
Cluster five modules are parallel connected to the CAN bus to
form a CAN bus network architecture, terminal resistors are set
within the BCM and ECM. Refer to figure below:

EN01

EN01

IP29

IP29

30

26

33

34

30

31

6

14

14                      

40

BCM

ECM

ABS

IP

DLC

9

15

ACU

IP35

IP35

IP03

IP03

IP12

IP12

CA13

CA13

FE11-1506b

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Data Communication System

Body Electric