Lan System (CAN): Other — Lan System (CAN) — Communication Devices

Caution

This article describes information to a vehicle and inspection procedures.
For trouble diagnosis procedure, refer to " «TROUBLE DIAGNOSIS PROCEDURE»(ref-621374-S15997834872014061000000) ".

Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT PRE-TENSIONER"

The Supplemental Restraint System such as "AIR BAG" and "SEAT BELT PRE-TENSIONER", used along with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front air bag, depending on the severity of a collision and whether the front occupants are buckled or unbuckled.

Information necessary to service the system safely is included in the SRS AIRBAG and SEAT BELTS of this Service Information.

WARNING

Always observe the following items for preventing accidental activation. To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death in the event of a collision that would result in air bag inflation, all maintenance must be performed by an authorized NISSAN/INFINITI dealer. Improper maintenance, including incorrect removal and installation of the SRS, can lead to personal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag Module, see " SRS AIR BAG SYSTEM ". Never use electrical test equipment on any circuit related to the SRS unless instructed to in this Service Information. SRS wiring harnesses can be identified by yellow and/or orange harnesses or harness connectors.

PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS

WARNING

Always observe the following items for preventing accidental activation. When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition ON or engine running, never use air or electric power tools or strike near the sensor(s) with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly causing serious injury. When using air or electric power tools or hammers, always switch the ignition OFF, disconnect the battery, and wait at least 3 minutes before performing any service.

Scheme 22

Scheme 22: Precautions for Removing Battery Terminal

When removing the 12V battery terminal, turn OFF the ignition switch and wait at least 30 seconds. NOTE: ECU may be active for several tens of seconds after the ignition switch is turned OFF. If the battery terminal is removed before ECU stops, then a DTC detection error or ECU data corruption may occur.
For vehicles with the 2-batteries, be sure to connect the main battery and the sub battery before turning ON the ignition switch. NOTE: If the ignition switch is turned ON with any one of the terminals of main battery and sub battery disconnected, then DTC may be detected.
After installing the 12V battery, always check "Self Diagnosis Result" of all ECUs and erase DTC. NOTE: The removal of 12V battery may cause a DTC detection error.

CAN Communication Line

The CAN communication line is a twisted pair wire consisting of strands of CAN-H (1) and CAN-L (2) and has noise immunity.

Scheme 23

Scheme 23: CAN Communication Line

Note. The CAN communication system has the characteristics of noise-resistant because this system produces digital signals by using the potential difference between the CAN-H line and the CAN-L line and has the twisted pair wire structure.

Since the CAN-H line and the CAN-L line are always adjacent to each other, the same degree of noise occurs, respectively, when a noise (1) occurs. Although the noise changes the voltage, the potential difference (2) between the CAN-H line and the CAN-L line is insensitive to noise. Therefore, noise-resistant signals can be obtained.

Scheme 24

CAN Signal Communications

Each control unit of the CAN communication system transmits signals through the CAN communication control circuit included in the control unit and receives only necessary signals from each control unit to perform various kinds of control.

Scheme 25

Scheme 25: CAN Signal Communications

Scheme 26

Example: Transmitted signals
Example: Received signals

Note. The above signal names and signal communications are provided for reference purposes. For CAN communications signals of this vehicle, refer to " CAN COMMUNICATION SYSTEM: CAN COMMUNICATION SIGNAL CHART ".

CAN COMMUNICATION SYSTEM: CAN Communication Control Circuit

CAN communication control circuit is incorporated into the control unit and transmits/receives CAN communication signals.

Scheme 27

Scheme 27: CAN COMMUNICATION SYSTEM: CAN Communication Control Circuit

Component	System description
CAN controller	It controls CAN communication signal transmission and reception, error detection, etc.
Transceiver IC	It converts digital signal into CAN communication signal, and CAN communication signal into digital signal.
Noise filter	It eliminates noise of CAN communication signal.
Termination circuit (1) (Resistance of approx. 120 ohms)	Generates a potential difference between CAN-H and CAN-L.
(1) These are the only control units wired with both ends of CAN communication system.

(1)	These are the only control units wired with both ends of CAN communication system.

CAN COMMUNICATION SYSTEM: CAN Communication Signal Chart

Refer to " HOW TO USE CAN COMMUNICATION SIGNAL CHART " for how to use CAN communication signal chart.

Note. Refer to " ABBREVIATION LIST " for the abbreviations of the connecting units.

Scheme 28

Scheme 28: CAN COMMUNICATION SYSTEM: CAN Communication Signal Chart

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Scheme 30

Note. CAN data of the air bag diagnosis sensor unit is not used by usual service work, thus it is omitted.

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Scheme 31: Wiring Diagram

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Scheme 32: Connector End Views

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Scheme 34

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Scheme 36

Interview Sheet

Note. Refer to " TROUBLE DIAGNOSIS PROCEDURE " for how to use interview sheet.

Scheme 37

Scheme 37: Interview Sheet

Main Line

Malfunction area	Reference
Main line between IPDM E/R and data link connector	" DIAGNOSIS PROCEDURE "
Main line between data link connector and air bag diagnosis sensor unit	" DIAGNOSIS PROCEDURE "
Main line between data link connector and multi display unit	" DIAGNOSIS PROCEDURE "

Branch Line

Malfunction area	Reference
ECM branch line circuit	" DIAGNOSIS PROCEDURE "
AWD control module branch line circuit	" DIAGNOSIS PROCEDURE "
ABS actuator and electric unit (control unit) branch line circuit	" DIAGNOSIS PROCEDURE "
IPDM E/R branch line circuit	" DIAGNOSIS PROCEDURE "
TCM branch line circuit	" DIAGNOSIS PROCEDURE "
Data link connector branch line circuit	" DIAGNOSIS PROCEDURE "
EPS control unit branch line circuit	" DIAGNOSIS PROCEDURE "
Combination meter branch line circuit	" DIAGNOSIS PROCEDURE "
Steering angle sensor branch line circuit	" DIAGNOSIS PROCEDURE "
Air bag diagnosis sensor unit branch line circuit	" DIAGNOSIS PROCEDURE "
A/C auto amp. branch line circuit	" DIAGNOSIS PROCEDURE "
Multi display unit branch line circuit	" DIAGNOSIS PROCEDURE "
BCM branch line circuit	" DIAGNOSIS PROCEDURE "

Short Circuit

Malfunction area	Reference
CAN communication circuit	" DIAGNOSIS PROCEDURE "

Lan System (CAN): Other Nissan Juke I facelift