Nissan Pathfinder (2009 year). Manual - part 254

EC-46

< FUNCTION DIAGNOSIS >

[VQ40DE]

EVAPORATIVE EMISSION SYSTEM

EVAPORATIVE EMISSION LINE DRAWING

PBIB2528E

2009 Pathfinder

EVAPORATIVE EMISSION SYSTEM

EC-47

< FUNCTION DIAGNOSIS >

[VQ40DE]

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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 page

ALBIA0366ZZ

2009 Pathfinder

EC-48

< FUNCTION DIAGNOSIS >

[VQ40DE]

INTAKE VALVE TIMING CONTROL

INTAKE VALVE TIMING CONTROL

Description

INFOID:0000000004297253

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 control solenoid
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)

Engine speed and piston position

Intake valve 
timing control

Intake valve timing control 
solenoid valve

Camshaft position sensor (PHASE)

Engine coolant temperature sensor

Engine coolant temperature

Wheel sensor

Vehicle speed*

PBIB3279E

2009 Pathfinder

VARIABLE INDUCTION AIR SYSTEM

EC-49

< FUNCTION DIAGNOSIS >

[VQ40DE]

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VARIABLE INDUCTION AIR SYSTEM

Description

INFOID:0000000004297254

SYSTEM DESCRIPTION

*: ECM determines the start signal status by the signals of engine speed and battery voltage.

When the engine is running at medium speed, the ECM sends the ON signal to the VIAS control solenoid
valve. This signal introduces the intake manifold vacuum into the power valve actuator and therefore closes
the power valve.
Under this condition, the effective intake manifold length is equivalent to the total length of passage A and pas-
sage B. This long intake manifold provides increased amount of intake air, which results in improved suction
efficiency and higher torque.
When engine is running at low or high speed, the ECM sends the OFF signal to the VIAS control solenoid
valve and the power valve is opened.
Under this condition, the effective intake manifold length is equivalent to the length of passage B. This short-
ened intake manifold length results in enhanced engine output due to reduced suction resistance under high
speeds.

COMPONENT DESCRIPTION

Power Valve

Sensor

Input Signal to ECM

ECM function

Actuator

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

Engine speed*

VIAS control

VIAS control solenoid valve

Mass air flow sensor

Amount of intake air

Engine coolant temperature sensor

Engine coolant temperature

Throttle position sensor

Throttle position

Accelerator pedal position sensor

Accelerator pedal position

Battery

Battery voltage*

PBIB1822E

2009 Pathfinder

EC-50

< FUNCTION DIAGNOSIS >

[VQ40DE]

VARIABLE INDUCTION AIR SYSTEM

The power valve is installed in intake manifold collector and used to
control the suction passage of the variable induction air control sys-
tem. It is set in the fully closed or fully opened position by the power
valve actuator operated by the vacuum stored in the surge tank. The
vacuum in the surge tank is controlled by the VIAS control solenoid
valve.

VIAS Control Solenoid Valve

The VIAS control solenoid valve cuts the intake manifold vacuum
signal for power valve control. It responds to ON/OFF signals from
the ECM. When the solenoid is off, the vacuum signal from the
intake manifold is cut. When the ECM sends an ON signal the coil
pulls the plunger downward and feeds the vacuum signal to the
power valve actuator.

BBIA0569E

BBIA0569E

2009 Pathfinder

VARIABLE INDUCTION AIR SYSTEM

EC-51

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Vacuum Hose Drawing

INFOID:0000000004297255

Refer to 

EC-28, "System Diagram"

 for Vacuum Control System.

PBIB2529E

2009 Pathfinder

EC-52

< FUNCTION DIAGNOSIS >

[VQ40DE]

ON BOARD DIAGNOSTIC (OBD) SYSTEM

ON BOARD DIAGNOSTIC (OBD) SYSTEM

Introduction

INFOID:0000000004297256

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-453

.)

Two Trip Detection Logic

INFOID:0000000004297257

When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are saved 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 saved in
the ECM memory, and the MIL illuminates. The MIL illuminates at the same time the DTC is saved. <2nd trip>
The “trip” in the “Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed during
vehicle operation. Specific on board diagnostic items will cause the ECM to illuminate or blink the MIL, and
save 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.

Emission-related diagnostic information

SAE Mode

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 

display-

ing

Blinking

Illuminat-

ed

Blinking

Illuminat-

ed

Misfire (Possible three way catalyst 
damage) — DTC: P0300 - P0306 is 
being detected

×

—

—

—

—

—

×

—

Misfire (Possible three way catalyst 
damage) — DTC: P0300 - P0306 is 
being detected

—

—

×

—

—

×

—

—

One trip detection diagnoses (Re-
fer to 

EC-456

.)

—

×

—

—

×

—

—

—

Except above

—

—

—

×

—

×

×

—

2009 Pathfinder

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-53

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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.
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:0000000004297258

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 reoccur, 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 saved in the ECM memory and the MIL illuminates. In other words,
the DTC is saved in the ECM memory and the MIL illuminates when the same malfunction occurs in two con-
secutive 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 saved. For malfunctions that blink or illuminate the MIL during
the 1st trip, the DTC and 1st trip DTC are saved 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 "EMISSION-RELATED DIAGNOSTIC INFOR-
MATION ITEMS". These items are required by legal regulations to continuously monitor the system/compo-
nent. In addition, the items monitored non-continuously 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-14, "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
 With GST

CONSULT-III or GST (Generic Scan Tool) Examples: P0340, P0850, P1148, etc.
These DTCs are prescribed by SAE J2012.
(CONSULT-III also displays the malfunctioning component or system.)

 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 and the Diagnostic Test Mode II do 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 as shown below. Therefore, using CONSULT-III (if
available) is recommended.

DTC or 1st trip DTC of a malfunction is displayed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-III.
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 saved in the ECM, the time data will be [1t].

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