Nissan Xterra. Manual - part 226

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< SYSTEM DESCRIPTION >

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CAN COMMUNICATION

CAN COMMUNICATION

System Description

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CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-

tiplex communication line with high data communication speed and excellent error detection ability. Many elec-

tronic control units are equipped onto a vehicle, and each control unit shares information and links with other

control units during operation (not independent). In CAN communication, control units are connected with 2

communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.

Each control unit transmits/receives data but selectively reads required data only.

Refer to 

LAN-45, "CAN System Specification Chart"

, about CAN communication for detail.

COOLING FAN CONTROL

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< SYSTEM DESCRIPTION >

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COOLING FAN CONTROL

Description

INFOID:0000000009483779

SYSTEM DESCRIPTION

Cooling Fan Control

*1: The ECM determines the start signal status by the signals of engine speed and battery voltage.
*2: This signal is sent to ECM via the CAN communication line.

The ECM controls the cooling fan corresponding to the vehicle speed, engine coolant temperature, refrigerant

pressure, and air conditioner ON signal. The control system has 3-step control [HIGH/LOW/OFF].

Cooling Fan Operation

Cooling Fan Relay Operation

The ECM controls cooling fan relays in the IPDM E/R via the CAN communication line.

Sensor

Input Signal to ECM

ECM function

Actuator

Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)

Engine speed*

1

Cooling fan 
control

IPDM E/R
(Cooling fan relays)

Battery

Battery voltage*

1

Wheel sensor

Vehicle speed*

2

Engine coolant temperature sensor

Engine coolant temperature

Air conditioner switch

Air conditioner ON signal*

2

Refrigerant pressure sensor

Refrigerant pressure

PBIB2531E

Cooling fan speed

Cooling fan relay

LO

HI

Stop (OFF)

OFF

OFF

Low (LOW)

ON

OFF

High (HI)

ON

ON

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< SYSTEM DESCRIPTION >

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EVAPORATIVE EMISSION SYSTEM

EVAPORATIVE EMISSION SYSTEM

Description

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SYSTEM DESCRIPTION

The evaporative emission system is used to reduce hydrocarbons emitted into the atmosphere from the fuel

system. This reduction of hydrocarbons is accomplished by activated charcoals in the EVAP canister.

The fuel vapor in the sealed fuel tank is led into the EVAP canister which contains activated carbon and the

vapor is stored there when the engine is not operating or when refueling to the fuel tank.

The vapor in the EVAP canister is purged by the air through the purge line to the intake manifold when the

engine is operating. EVAP canister purge volume control solenoid valve is controlled by ECM. When the

engine operates, the flow rate of vapor controlled by EVAP canister purge volume control solenoid valve is

proportionally regulated as the air flow increases.

EVAP canister purge volume control solenoid valve also shuts off the vapor purge line during decelerating.

PBIB3639E

EVAPORATIVE EMISSION SYSTEM

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EVAPORATIVE EMISSION LINE DRAWING

PBIB2528E