Nissan Pathfinder (2008 year). Manual - part 303

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-541

< FUNCTION DIAGNOSIS >

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EXPLANATION FOR DRIVING PATTERNS EXCEPT FOR “MISFIRE <EXHAUST QUALITY DETE-
RIORATION>”, “FUEL INJECTION SYSTEM”

*1: When the same malfunction is de-

tected in two consecutive trips, MIL 
will light up.

*2: MIL will go off after vehicle is driven 3 

times (pattern B) without any mal-
functions.

*3: When the same malfunction is de-

tected in two consecutive trips, the 
DTC and the freeze frame data will be 
stored in ECM.

*4: The DTC and the freeze frame data 

will not be displayed any longer after 
vehicle is driven 40 times (pattern A) 
without the same malfunction.
(The DTC and the freeze frame data 
still remain in ECM.)

*5: When a malfunction is detected for 

the first time, the 1st trip DTC and the 
1st trip freeze frame data will be 
stored in ECM.

*6: 1st trip DTC will be cleared after vehi-

cle is driven once (pattern B) without 
the same malfunction.

*7: When the same malfunction is de-

tected in the 2nd trip, the 1st trip 
freeze frame data will be cleared.

SEF393SD

EC-542

< FUNCTION DIAGNOSIS >

[VK56DE]

ON BOARD DIAGNOSTIC (OBD) SYSTEM

<Driving Pattern A>

• The A counter will be cleared when the malfunction is detected regardless of (1) - (4).
• The A counter will be counted up when (1) - (4) are satisfied without the same malfunction.
• The DTC will not be displayed after the A counter reaches 40.

<Driving Pattern B>

Driving pattern B means the vehicle operation as follows:
All components and systems should be monitored at least once by the OBD system.
• The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.
• The B counter will be counted up when driving pattern B is satisfied without any malfunctions.
• The MIL will go off when the B counter reaches 3 (*2 in OBD SYSTEM OPERATION CHART).

CONSULT-III Function (ENGINE)

INFOID:0000000001537619

FUNCTION

*: The following emission-related diagnostic information is cleared when the ECM memory is erased.

• Diagnostic trouble codes

• 1st trip diagnostic trouble codes

• Freeze frame data

• 1st trip freeze frame data

• System readiness test (SRT) codes

• Test  values

ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION

AEC574

Diagnostic test mode

Function

Work support

This mode enables a technician to adjust some devices faster and more accurately by following the in-
dications on the CONSULT-III unit.

Self-diagnostic results

Self-diagnostic results such as 1st trip DTC, DTCs and 1st trip freeze frame data or freeze frame data 
can be read and erased quickly.*

Data monitor

Input/Output data in the ECM can be read.

Active test

Diagnostic Test Mode in which CONSULT-III drives some actuators apart from the ECMs and also shifts 
some parameters in a specified range.

Function test

This mode is used to inform customers when their vehicle condition requires periodic maintenance.

DTC & SRT confirmation

The status of system monitoring tests and the self-diagnosis status/result can be confirmed.

ECU Identification

ECM part number can be read.

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-543

< FUNCTION DIAGNOSIS >

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Item

DIAGNOSTIC TEST MODE

WORK 

SUP-

PORT

SELF-DIAGNOSTIC 

RESULTS

DATA 

MONI-

TOR

ACTIVE 

TEST

DTC & SRT

CONFIRMATION

DTC*1

FREEZE 

FRAME 
DATA*2

SRT 

STATUS

DTC 

WORK 

SUP-

PORT

E

N

GINE

 CON

T

RO

L COMPONENT 

P

ARTS

INPUT

Crankshaft position sensor (POS)

×

×

×

Camshaft position sensor (PHASE)

×

×

×

Mass air flow sensor

×

×

Engine coolant temperature sensor

×

×

×

×

Air fuel ratio (A/F) sensor 1

×

×

×

×

Heated oxygen sensor 2

×

×

×

×

Wheel sensor

×

×

×

Accelerator pedal position sensor

×

×

Throttle position sensor

×

×

×

Fuel tank temperature sensor

×

×

×

EVAP control system pressure sen-
sor

×

×

Intake air temperature sensor

×

×

×

Knock sensor

×

Refrigerant pressure sensor

×

Closed throttle position switch (ac-
celerator pedal position sensor sig-
nal)

×

Air conditioner switch

×

Park/neutral position (PNP) switch

×

×

Stop lamp switch

×

×

Power steering pressure sensor

×

×

Battery voltage

×

Load signal

×

Intake valve timing control position 
sensor

×

×

Fuel level sensor

×

×

Battery current sensor

×

×

ASCD steering switch

×

×

ASCD brake switch

×

×

EC-544

< FUNCTION DIAGNOSIS >

[VK56DE]

ON BOARD DIAGNOSTIC (OBD) SYSTEM

X: Applicable

*1: This item includes 1st trip DTCs.

*2: This mode includes 1st trip freeze frame data or freeze frame data. The items appear on CONSULT-III screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to 

EC-919, "DTC Index"

.

*3: Always “CMPLT” is displayed.

Refer to “CONSULT-III Software Operation Manual” for more information.

WORK SUPPORT MODE

Work Item

E

N

G

IN

E

 CON

T

RO

L COMPONENT 

P

ARTS

OUTPUT

Fuel injector

×

×

Power transistor (Ignition timing)

×

×

Throttle control motor relay

×

×

Throttle control motor

×

EVAP canister purge volume con-
trol solenoid valve

×

×

×

×

Air conditioner relay

×

Fuel pump relay

×

×

×

Cooling fan relay

×

×

×

Air fuel ratio (A/F) sensor 1 heater

×

×

×

*3

Heated oxygen sensor 2 heater

×

×

×

*3

EVAP canister vent control valve

×

×

×

×

Intake valve timing control solenoid 
valve

×

×

×

Alternator

×

×

Calculated load value

×

×

Item

DIAGNOSTIC TEST MODE

WORK 

SUP-

PORT

SELF-DIAGNOSTIC 

RESULTS

DATA 

MONI-

TOR

ACTIVE 

TEST

DTC & SRT

CONFIRMATION

DTC*1

FREEZE 

FRAME 
DATA*2

SRT 

STATUS

DTC 

WORK 

SUP-

PORT

WORK ITEM

CONDITION

USAGE

FUEL PRESSURE RELEASE

• FUEL PUMP WILL STOP BY TOUCHING “START” DUR-

ING IDLING.
CRANK A FEW TIMES AFTER ENGINE STALLS.

When releasing fuel pressure from 
fuel line

IDLE AIR VOL LEARN

• THE IDLE AIR VOLUME THAT KEEPS THE ENGINE 

WITHIN THE SPECIFIED RANGE IS MEMORIZED IN 
ECM.

When learning the idle air volume

SELF-LEARNING CONT

• THE COEFFICIENT OF SELF-LEARNING CONTROL 

MIXTURE RATIO RETURNS TO THE ORIGINAL COEF-
FICIENT.

When clearing the coefficient of 
self-learning control value

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-545

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*1: This function is not necessary in the usual service procedure.

SELF-DIAG RESULTS MODE

Self Diagnostic Item

Regarding items of DTC and 1st trip DTC, refer to 

EC-919, "DTC Index"

.

Freeze Frame Data and 1st Trip Freeze Frame Data

EVAP SYSTEM CLOSE

CLOSE THE EVAP CANISTER VENT CONTROL VALVE IN 
ORDER TO MAKE EVAP SYSTEM CLOSE UNDER THE 
FOLLOWING CONDITIONS.
• IGN  SW  ON
• ENGINE NOT RUNNING
• AMBIENT TEMPERATURE IS ABOVE 0

°

C (32

°

F).

• NO VACUUM AND NO HIGH PRESSURE IN EVAP SYS-

TEM

•  FUEL TANK TEMP. IS MORE THAN 0

°

C (32

°

F).

• WITHIN 10 MINUTES AFTER STARTING “EVAP SYS-

TEM CLOSE”

• WHEN TRYING TO EXECUTE “EVAP SYSTEM CLOSE” 

UNDER THE CONDITION EXCEPT ABOVE, CONSULT-
III WILL DISCONTINUE IT AND DISPLAY APPROPRI-
ATE INSTRUCTION.
NOTE:
WHEN STARTING ENGINE, CONSULT-III MAY DIS-
PLAY “BATTERY VOLTAGE IS LOW. CHARGE BAT-
TERY”, EVEN IN USING CHARGED BATTERY.

When detecting EVAP vapor leak 
point of EVAP system

VIN REGISTRATION

• IN THIS MODE, VIN IS REGISTERED IN ECM

When registering VIN in ECM

TARGET IDLE RPM ADJ*

1

• IDLE CONDITION

When setting target idle speed

TARGET IGN TIM ADJ*

1

• IDLE CONDITION

When adjusting target ignition tim-
ing

WORK ITEM

CONDITION

USAGE

Freeze frame data 

item*

Description

DIAG TROUBLE 
CODE
[PXXXX]

• The engine control component part/control system has a trouble code, it is displayed as PXXXX. (Refer to 

EC-919, "DTC Index"

.)

FUEL SYS-B1

• “Fuel injection system status” at the moment a malfunction is detected is displayed.
• One mode in the following is displayed.

Mode2: Open loop due to detected system malfunction
Mode3: Open loop due to driving conditions (power enrichment, deceleration enleanment)
Mode4: Closed loop - using oxygen sensor(s) as feedback for fuel control
Mode5: Open loop - has not yet satisfied condition to go to closed loop

FUEL SYS-B2

CAL/LD VALUE [%]

• The calculated load value at the moment a malfunction is detected is displayed.

COOLANT TEMP
[

°

C] or [

°

F]

• The engine coolant temperature at the moment a malfunction is detected is displayed.

L-FUEL TRM-B1 [%]

• “Long-term fuel trim” at the moment a malfunction is detected is displayed.
• The long-term fuel trim indicates much more gradual feedback compensation to the base fuel schedule than 

short-term fuel trim.

L-FUEL TRM-B2 [%]

S-FUEL TRM-B1 [%]

• “Short-term fuel trim” at the moment a malfunction is detected is displayed.
• The short-term fuel trim indicates dynamic or instantaneous feedback compensation to the base fuel sched-

ule.

S-FUEL TRM-B2 [%]

ENGINE SPEED [rpm]

• The engine speed at the moment a malfunction is detected is displayed.

VEHICL SPEED
[km/h] or [mph]

• The vehicle speed at the moment a malfunction is detected is displayed.

ABSOL TH-P/S
[%]

• The throttle valve opening at the moment a malfunction is detected is displayed.

EC-546

< FUNCTION DIAGNOSIS >

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ON BOARD DIAGNOSTIC (OBD) SYSTEM

*: The item is the same as that of 1st trip freeze frame data.

DATA MONITOR MODE

Monitored Item

×

: Applicable

B/FUEL SCHDL 
[msec]

• The base fuel schedule at the moment a malfunction is detected is displayed.

INT/A TEMP SE
[

°

C] or [

°

F]

• The intake air temperature at the moment a malfunction is detected is displayed.

INT MANI PRES [kPa] 

• Always a certain value is displayed.
• These items are not efficient for R51 models.

FTFMCH1

Freeze frame data 

item*

Description

Monitored item 

[Unit]

ECM IN-

PUT SIG-

NALS

MAIN 

SIGNALS

Description

Remarks

ENG SPEED [rpm]

×

×

• Indicates the engine speed computed 

from the signal of the crankshaft position 
sensor (POS) and camshaft position 
sensor (PHASE).

• Accuracy becomes poor if engine speed 

drops below the idle rpm.

• If the signal is interrupted while the en-

gine is running, an abnormal value may 
be indicated.

MAS A/F SE-B1 [V]

×

×

• The signal voltage of the mass air flow 

sensor is displayed.

• When the engine is stopped, a certain 

value is indicated.

• When engine is running specification 

range is indicated in “SPEC”.

B/FUEL SCHDL 
[msec]

×

• Base fuel schedule indicates the fuel in-

jection pulse width programmed into 
ECM, prior to any learned on board cor-
rection.

• When engine is running specification 

range is indicated in “SPEC”.

A/F ALPHA-B1 [%]

×

• The mean value of the air-fuel ratio feed-

back correction factor per cycle is indi-
cated.

• When the engine is stopped, a certain 

value is indicated.

• When engine is running specification 

range is indicated in “SPEC”.

• This data also includes the data for the 

air-fuel ratio learning control.

A/F ALPHA-B2 [%]

×

COOLAN TEMP/S 
[

°

C] or [

°

F]

×

×

• The engine coolant temperature (deter-

mined by the signal voltage of the engine 
coolant temperature sensor) is dis-
played.

• When the engine coolant temperature 

sensor is open or short-circuited, ECM 
enters fail-safe mode. The engine cool-
ant temperature determined by the ECM 
is displayed.

A/F SEN1 (B1) [V]

×

×

• The A/F signal computed from the input 

signal of the A/F sensor 1 is displayed.

A/F SEN1 (B2) [V]

×

HO2S2 (B1) [V]

×

• The signal voltage of the heated oxygen 

sensor 2 is displayed.

HO2S2 (B2) [V]

×

HO2S2 MNTR (B1) 
[RICH/LEAN]

×

• Display of heated oxygen sensor 2 sig-

nal:
RICH: means the amount of oxygen after 
three way catalyst is relatively small.
LEAN: means the amount of oxygen af-
ter three way catalyst is relatively large.

• When the engine is stopped, a certain 

value is indicated.

HO2S2 MNTR (B2) 
[RICH/LEAN]

×

VHCL SPEED SE 
[km/h] or [mph]

×

×

• The vehicle speed computed from the 

vehicle speed signal sent from combina-
tion meter is displayed.

BATTERY VOLT 
[V]

×

×

• The power supply voltage of ECM is dis-

played.

ON BOARD DIAGNOSTIC (OBD) SYSTEM

EC-547

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ACCEL SEN 1 [V]

×

×

• The accelerator pedal position sensor 

signal voltage is displayed.

• ACCEL SEN 2 signal is converted by 

ECM internally. Thus, it differs from ECM 
terminal voltage signal.

ACCEL SEN 2 [V]

×

TP SEN 1-B1

×

×

• The throttle position sensor signal volt-

age is displayed.

• TP SEN 2-B1 signal is converted by 

ECM internally. Thus, it differs from ECM 
terminal voltage signal.

TP SEN 2-B1

×

FUEL T/TMP SE 
[

°

C] or [

°

F]

×

• The fuel temperature (determined by the 

signal voltage of the fuel tank tempera-
ture sensor) is displayed.

INT/A TEMP SE 
[

°

C] or [

°

F]

×

×

• The intake air temperature (determined 

by the signal voltage of the intake air 
temperature sensor) is indicated.

EVAP SYS PRES 
[V]

×

• The signal voltage of EVAP control sys-

tem pressure sensor is displayed.

FUEL LEVEL SE 
[V]

×

• The signal voltage of the fuel level sen-

sor is displayed.

START SIGNAL 
[ON/OFF]

×

×

• Indicates start signal status [ON/OFF] 

computed by the ECM according to the 
signals of engine speed and battery volt-
age.

• After starting the engine, [OFF] is dis-

played regardless of the starter signal.

CLSD THL POS 
[ON/OFF]

×

×

• Indicates idle position [ON/OFF] comput-

ed by ECM according to the accelerator 
pedal position sensor signal.

AIR COND SIG 
[ON/OFF]

×

×

• Indicates [ON/OFF] condition of the air 

conditioner switch as determined by the 
air conditioner signal.

P/N POSI SW
[ON/OFF]

×

×

• Indicates [ON/OFF] condition from the 

park/neutral position (PNP) switch sig-
nal.

PW/ST SIGNAL 
[ON/OFF]

×

×

• [ON/OFF] condition of the power steering 

system (determined by the signal voltage 
of the power steering pressure sensor 
signal) is indicated.

LOAD SIGNAL 
[ON/OFF]

×

×

• Indicates [ON/OFF] condition from the 

electrical load signal.
ON: Lighting switch is in 2nd position.
OFF: Lighting switch is OFF.

IGNITION SW
[ON/OFF]

×

• Indicates [ON/OFF] condition from igni-

tion switch signal.

HEATER FAN SW
[ON/OFF]

×

• Indicates [ON/OFF] condition from heat-

er fan switch signal.

BRAKE SW
[ON/OFF]

×

• Indicates [ON/OFF] condition from the 

stop lamp switch signal.

INJ PULSE-B1 
[msec]

×

• Indicates the actual fuel injection pulse 

width compensated by ECM according to 
the input signals.

• When the engine is stopped, a certain 

computed value is indicated.

INJ PULSE-B2 
[msec]

IGN TIMING [BT-
DC]

×

• Indicates the ignition timing computed by 

ECM according to the input signals.

• When the engine is stopped, a certain 

value is indicated.

CAL/LD VALUE [%]

• “Calculated load value” indicates the val-

ue of the current air flow divided by peak 
air flow.

Monitored item 

[Unit]

ECM IN-

PUT SIG-

NALS

MAIN 

SIGNALS

Description

Remarks

EC-548

< FUNCTION DIAGNOSIS >

[VK56DE]

ON BOARD DIAGNOSTIC (OBD) SYSTEM

MASS AIRFLOW 
[g·m/s]

• Indicates the mass air flow computed by 

ECM according to the signal voltage of 
the mass air flow sensor.

PURG VOL C/V [%]

• Indicates the EVAP canister purge vol-

ume control solenoid valve control value 
computed by the ECM according to the 
input signals.

• The opening becomes larger as the val-

ue increases.

INT/V TIM (B1) 
[

°

CA]

• Indicates [

°

CA] of intake camshaft ad-

vanced angle. 

INT/V TIM (B2) 
[

°

CA]

INT/V SOL (B1) [%]

• The control value of the intake valve tim-

ing control solenoid valve (determined by 
ECM according to the input signals) is in-
dicated.

• The advance angle becomes larger as 

the value increases.

INT/V SOL (B2) [%]

AIR COND RLY 
[ON/OFF]

×

• The air conditioner relay control condi-

tion (determined by ECM according to 
the input signals) is indicated.

FUEL PUMP RLY 
[ON/OFF]

×

• Indicates the fuel pump relay control con-

dition determined by ECM according to 
the input signals.

VENT CONT/V 
[ON/OFF]

• The control condition of the EVAP canis-

ter vent control valve (determined by 
ECM according to the input signals) is in-
dicated.
ON: Closed
OFF: Open

THRTL RELAY 
[ON/OFF]

×

• Indicates the throttle control motor relay 

control condition determined by the ECM 
according to the input signals.

COOLING FAN
[HI/OFF]

×

• The control condition of the cooling fan 

(determined by ECM according to the in-
put signals) is indicated.
HI: High speed operation
OFF: Stop

HO2S2 HTR (B1) 
[ON/OFF]

• Indicates [ON/OFF] condition of heated 

oxygen sensor 2 heater determined by 
ECM according to the input signals.

HO2S2 HTR (B2) 
[ON/OFF]

I/P PULLY SPD
[rpm]

×

• Indicates the engine speed computed 

from the turbine revolution sensor signal.

VEHICLE SPEED
[km/h] or [mph]

×

• Indicates the vehicle speed computed 

from the revolution sensor signal.

IDL A/V LEARN 
[YET/CMPLT]

• Display the condition of Idle Air Volume 

Learning
YET: Idle Air Volume Learning has not 
been performed yet.
CMPLT: Idle Air Volume Learning has al-
ready been performed successfully.

TRVL AFTER MIL 
[km] or [mile]

• Distance traveled while MIL is activated.

Monitored item 

[Unit]

ECM IN-

PUT SIG-

NALS

MAIN 

SIGNALS

Description

Remarks