Nissan Pathfinder (2009 year). Manual - part 313

EC-518

< FUNCTION DIAGNOSIS >

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CAN COMMUNICATION

CAN COMMUNICATION

System Description

INFOID:0000000003936468

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-58, "CAN Communication Signal Chart"

, about CAN communication for detail.

2009 Pathfinder

COOLING FAN CONTROL

EC-519

< FUNCTION DIAGNOSIS >

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COOLING FAN CONTROL

Description

INFOID:0000000003936469

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 speed corresponding to the vehicle speed, engine coolant temperature,
refrigerant pressure and air conditioner ON signal. The control system has a 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

Unified meter control unit

Vehicle speed*

2

Engine coolant temperature sensor

Engine coolant temperature

Air conditioner switch

Air conditioner ON signal*

2

Refrigerant pressure sensor

Refrigerant pressure

JMBIA0700GB

Cooling fan speed

Cooling fan relay

LO

HI

Stop (OFF)

OFF

OFF

Low (LOW)

ON

OFF

High (HI)

ON

ON

2009 Pathfinder

EC-520

< FUNCTION DIAGNOSIS >

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EVAPORATIVE EMISSION SYSTEM

EVAPORATIVE EMISSION SYSTEM

Description

INFOID:0000000003936470

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 and
idling.

PBIB3639E

2009 Pathfinder

EVAPORATIVE EMISSION SYSTEM

EC-521

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EVAPORATIVE EMISSION LINE DRAWING

PBIB2053E

2009 Pathfinder

EC-522

< FUNCTION DIAGNOSIS >

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EVAPORATIVE EMISSION SYSTEM

1.

EVAP vapor purge line

2.

EVAP control system pressure sen-
sor

3.

EVAP canister vent control valve

4.

EVAP canister

5.

Drain filter

6.

Fuel filler pipe

: Vehicle front

: Previous figure

ALBIA0366ZZ

2009 Pathfinder

INTAKE VALVE TIMING CONTROL

EC-523

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INTAKE VALVE TIMING CONTROL

Description

INFOID:0000000003936471

SYSTEM DESCRIPTION

*: This signal is sent to the ECM via the CAN communication line

This mechanism hydraulically controls cam phases continuously with the fixed operating angle of the intake
valve.
The ECM receives signals such as crankshaft position, camshaft position, engine speed and engine coolant
temperature. Then, the ECM sends ON/OFF pulse duty signals to the intake valve timing (IVT) control sole-
noid valve depending on driving status. This makes it possible to control the shut/open timing of the intake
valve to increase engine torque in low/mid speed range and output in high-speed range.

Sensor

Input signal to ECM

ECM function

Actuator

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

Engine speed

Intake valve 
timing control

Intake valve timing control 
solenoid valve

Intake valve timing control position sensor 

Intake valve timing signal

Engine coolant temperature sensor

Engine coolant temperature

Unified meter control unit

Vehicle speed*

PBIB3276E

2009 Pathfinder

EC-524

< FUNCTION DIAGNOSIS >

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ON BOARD DIAGNOSTIC (OBD) SYSTEM

ON BOARD DIAGNOSTIC (OBD) SYSTEM

Introduction

INFOID:0000000003936472

The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emission-related diagnostic information including:

The above information can be checked using procedures listed in the table below.

×

: Applicable

—: Not applicable

*: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.

The malfunction indicator lamp (MIL) on the instrument panel illuminates when the same malfunction is
detected in two consecutive trips (Two trip detection logic), or when the ECM enters fail-safe mode. (Refer to

EC-919, "Fail-Safe Chart"

.)

Two Trip Detection Logic

INFOID:0000000003936473

When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MIL will not illuminate at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MIL illuminates. The MIL illuminates at the same time when the DTC is stored.
<2nd trip> The “trip” in the “Two Trip Detection Logic” means a driving mode in which self-diagnosis is per-
formed during vehicle operation. Specific on board diagnostic items will cause the ECM to illuminate or blink
the MIL, and store DTC and Freeze Frame data, even in the 1st trip, as shown below.

×

: Applicable

—: Not applicable

When there is an open circuit on MIL circuit, the ECM cannot warn the driver by illuminating MIL when there is
malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means
of operating fail-safe function.

Emission-related diagnostic information

Diagnostic service

Diagnostic Trouble Code (DTC)

Service $03 of SAE J1979

Freeze Frame data

Service $02 of SAE J1979

System Readiness Test (SRT) code

Service $01 of SAE J1979

1st Trip Diagnostic Trouble Code (1st Trip DTC)

Service $07 of SAE J1979

1st Trip Freeze Frame data

—

Test values and Test limits

Service $06 of SAE J1979

Calibration ID

Service $09 of SAE J1979

DTC

1st trip DTC

Freeze 

Frame data

1st trip Freeze 

Frame data

SRT code

SRT status

Test value

CONSULT-III

×

×

×

×

×

×

—

GST

×

×

×

—

×

×

×

ECM

×

×

*

—

—

—

×

—

Items

MIL

DTC

1st trip DTC

1st trip

2nd trip 

1st trip 

displaying

2nd trip 

displaying

1st trip 

displaying

2nd trip 

displaying

Blinking

Illuminates

Blinking

Illuminates

Misfire (Possible three way catalyst 
damage) — DTC: P0300 - P0308 is 
being detected

×

—

—

—

—

—

×

—

Misfire (Possible three way catalyst 
damage) — DTC: P0300 - P0308 is 
being detected

—

—

×

—

—

×

—

—

One trip detection diagnoses (Re-
fer to 

EC-921, "DTC Index"

.)

—

×

—

—

×

—

—

—

Except above

—

—

—

×

—

×

×

—

2009 Pathfinder

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-525

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The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands the
driver to repair the malfunction.

Emission-related Diagnostic Information

INFOID:0000000003936474

DTC AND 1ST TRIP DTC

The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not recur, the 1st trip DTC
will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is saved in the ECM memory. The MIL will not
illuminate (two trip detection logic). If the same malfunction is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are stored in the ECM memory and the MIL illuminates. In other
words, the DTC is stored in the ECM memory and the MIL illuminates when the same malfunction occurs in
two consecutive trips. If a 1st trip DTC is saved and a non-diagnostic operation is performed between the 1st
and 2nd trips, only the 1st trip DTC will continue to be stored. For malfunctions that blink or illuminate the MIL
during the 1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in “HOW TO
ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION”.
For malfunctions in which 1st trip DTCs are displayed, refer to 

EC-921, "DTC Index"

. These items are required

by legal regulations to continuously monitor the system/component. In addition, the items monitored non-con-
tinuously are also displayed on CONSULT-III.
1st trip DTC is specified in Service $07 of SAE J1979. 1st trip DTC detection occurs without illuminating the
MIL and therefore does not warn the driver of a malfunction. However, 1st trip DTC detection will not prevent
the vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step 2, refer to 

EC-490, "Trouble Diagnosis Introduction"

. Then per-

form DTC Confirmation Procedure or Overall Function Check to try to duplicate the malfunction. If the mal-
function is duplicated, the item requires repair.

How to Read DTC and 1st Trip DTC

DTC and 1st trip DTC can be read by the following methods.

 With CONSULT-III

CONSULT-III displays the DTC in “SELF DIAGNOSTIC RESULT” mode.
Examples: P0340, P0850, P1148, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-III also displays the malfunctioning component or system.)
Time data indicates how many times the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be [0].
If a 1st trip DTC is stored in the ECM, the time data will be [1t].

 With GST

GST (Generic Scan Tool) displays the DTC in Diagnostic Service $03.
Examples: P0340, P0850, P1148, etc.
These DTCs are prescribed by SAE J2012.
1st trip DTC is displayed in Diagnostic Service $07.

 No Tools

The number of blinks of the MIL in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0340, 0850, 1148, etc.
These DTCs are controlled by NISSAN.
• 1st trip DTC No. is the same as DTC No.
• Output of a DTC indicates a malfunction. However, GST or the Diagnostic Test Mode II does not indi-

cate whether the malfunction is still occurring or has occurred in the past and has returned to nor-
mal. CONSULT-III can identify malfunction status. Therefore, using CONSULT-III (if available) is
recommended.

FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATA

The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short-term fuel trim, long-term fuel trim, engine speed, vehicle speed, absolute throttle position, base
fuel schedule and intake air temperature at the moment a malfunction is detected.

Engine operating condition in fail-safe mode

Engine speed will not rise more than 2,500 rpm due to the fuel cut

2009 Pathfinder