Nissan Pathfinder. Instruction - part 439

EC-62

< SYSTEM DESCRIPTION >

[VQ35DE]

DIAGNOSIS SYSTEM (ECM)

DTCs and 1st trip DTCs related to the malfunction are displayed in “self-diag results”.

• When ECM detects a 1st trip DTC, 1t” is displayed for “TIME”.

• When ECM has detected a current DTC, “0” is displayed for “TIME”.

• If “TIME” is neither “0” nor “1t”, the DTC occurred in the past and ECM shows the number of times the vehi-

cle has been driven since the last detection of the DTC.

How to Erase DTC and 1st Trip DTC

NOTE:

If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10 sec-

onds and then turn it ON (engine stopped) again.
1. Select “ENGINE” with CONSULT.
2. Select “SELF-DIAG RESULTS”.
3. Touch “ERASE”. (DTC in ECM will be erased.)

Freeze Frame Data and 1st Trip Freeze Frame Data

*: The items are the same as those of 1st trip freeze frame data.

DATA MONITOR MODE

NOTE:

The following table includes information (items) inapplicable to this vehicle. For information (items) applicable

to this vehicle, refer to CONSULT display items.

Monitored Item

For reference values of the following items, refer to 

EC-73, "Reference Value"

.

Freeze frame data item*

Description

DIAG TROUBLE CODE
[PXXXX]

The engine control component part/control system has a trouble code that is displayed as PXXXX. (Re-
fer to 

EC-91, "DTC Index"

.)

FUEL SYS-B1

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

COMBUST CONDITION

These items are displayed but are not applicable to this model.

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 sched-

ule 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 

schedule.

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.

INT MANI PRES [kPa] 

These items are displayed but are not applicable to this model.

ABSOL TH·P/S [%]

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

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.

DIAGNOSIS SYSTEM (ECM)

EC-63

< SYSTEM DESCRIPTION >

[VQ35DE]

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×: Applicable

Monitored item

Unit

Monitor Item Selec-

tion

Description

Remarks

ECU IN-

PUT SIG-

NALS

MAIN-

SIG-

NALS

ENG SPEED

rpm

×

×

Indicates the engine speed comput-
ed 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 engine is running, an abnor-
mal 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, specifi-

cation range is indicated in 
“SPEC”.

B/FUEL SCHDL

ms

×

×

“Base fuel schedule” indicates the 
fuel injection pulse width pro-
grammed into ECM, prior to any 
learned on board correction.

• When engine is running, specifi-

cation range is indicated in 
“SPEC”.

A/F ALPHA-B1

%

The mean value of the air-fuel ratio 
feedback correction factor per cycle 
is indicated.

• When the engine is stopped, a 

certain value is indicated.

• This data also includes the data 

for the air-fuel ratio learning con-
trol.

• When engine is running, specifi-

cation range is indicated in 
“SPEC”.

A/F ALPHA-B2

COOLANT TEMP/S

°C or °F

×

×

The engine coolant temperature (de-
termined by the signal voltage of the 
engine coolant temperature sensor) 
is displayed.

When the engine coolant tempera-
ture sensor is open or short-circuit-
ed, ECM enters fail-safe mode. The 
engine coolant temperature deter-
mined by the ECM is displayed.

A/F SEN1 (B1)

V

×

×

The A/F signal computed from the 
input signal of the air fuel ratio (A/F) 
sensor 1 is displayed.

HO2S2 (B1)

V

×

×

The signal voltage of the heated ox-
ygen sensor 2 is displayed.

HO2S2 (B2)

×

×

HO2S2 MNTR(B1)

RICH/

LEAN

×

Display of heated oxygen sensor 2 
signal:
• RICH: means the amount of oxy-

gen after three way catalyst is rel-
atively small.

• LEAN: means the amount of oxy-

gen after three way catalyst is rel-
atively large.

When the engine is stopped, a cer-
tain value is indicated.

HO2S2 MNTR(B2)

×

VHCL SPEED SE

km/h or 

mph

×

×

The vehicle speed computed from 
the vehicle speed signal sent from 
combination meter is displayed.

BATTERY VOLT

V

The power supply voltage of ECM is 
displayed.

ACCEL SEN 1

V

The accelerator pedal position sen-
sor signal voltage is displayed.

ACCEL SEN 2 signal is converted 
by ECM internally. Thus, it differs 
from ECM terminal voltage signal.

ACCEL SEN 2

TP SEN 1-B1

V

×

×

The throttle position sensor signal 
voltage is displayed.

TP SEN 2-B1 signal is converted by 
ECM internally. Thus, it differs from 
ECM terminal voltage signal.

TP SEN 2-B1

×

×

EC-64

< SYSTEM DESCRIPTION >

[VQ35DE]

DIAGNOSIS SYSTEM (ECM)

FUEL T/TMP SE

°C or °F

The fuel temperature (determined by 
the signal voltage of the fuel tank 
temperature sensor) is displayed.

EVAP SYS PRES

V

The signal voltage of EVAP control 
system pressure sensor is dis-
played.

FUEL LEVEL SE

V

×

The signal voltage of the fuel level 
sensor is displayed.

START SIGNAL

On/Off

Indicates start signal status [On/Off] 
computed by the ECM according to 
the signals of engine speed and bat-
tery voltage.

After starting the engine, [Off] is dis-
played regardless of the starter sig-
nal.

CLSD THL POS

On/Off

×

×

Indicates idle position [On/Off] com-
puted by ECM according to the ac-
celerator 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.

PW/ST SIGNAL

On/Off

×

×

[On/Off] condition of the power 
steering system (determined by the 
signal voltage of the power steering 
pressure sensor) is indicated.

LOAD SIGNAL

On/Off

×

×

Indicates [On/Off] condition from the 
electrical load signal.
• On: Rear window defogger switch 

is ON and/or lighting switch is in 
2nd position.

• Off: Both rear window defogger 

switch and lighting switch are 
OFF.

IGNITION SW

On/Off

×

×

Indicates [On/Off] condition from ig-
nition switch signal.

HEATER FAN SW

On/Off

×

Indicates [On/Off] condition from the 
heater 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 cer-
tain computed value is indicated.

INJ PULSE-B2

IGN TIMING

BTDC

×

Indicates the ignition timing comput-
ed by ECM according to the input 
signals.

When the engine is stopped, a cer-
tain value is indicated.

CAL/LD VALUE

%

“Calculated load value” indicates the 
value of the current air flow divided 
by peak air flow.

MASS AIRFLOW

g/s

Indicates the mass air flow comput-
ed by ECM according to the signal 
voltage of the mass air flow sensor.

Monitored item

Unit

Monitor Item Selec-

tion

Description

Remarks

ECU IN-

PUT SIG-

NALS

MAIN-

SIG-

NALS

DIAGNOSIS SYSTEM (ECM)

EC-65

< SYSTEM DESCRIPTION >

[VQ35DE]

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EC

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P

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PURG VOL C/V

%

• Indicates the EVAP canister purge 

volume control solenoid valve 
control value computed by the 
ECM according to the input sig-
nals.

• The opening becomes larger as 

the value increases.

INT/V TIM (B1)

°CA

Indicates [

°CA] of intake camshaft 

advance angle. 

INT/V TIM (B2)

INT/V SOL(B1)

%

• The control value of the intake 

valve timing control solenoid valve 
(determined by ECM according to 
the input signals) is indicated.

• The advance angle becomes larg-

er as the value increases.

INT/V SOL(B2)

VIAS S/V-1

On/Off

The control condition of the VIAS 
control solenoid valve 1 (determined 
by ECM according to the input sig-
nals) is indicated.
• On: VIAS control solenoid valve 1 

is operating.

• Off: VIAS control solenoid valve 1 

is not operating.

AIR COND RLY

On/Off

The air conditioner relay control con-
dition (determined by ECM accord-
ing to the input signals) is indicated.

ENGINE MOUNT

IDLE/
TRVL

The control condition of the electron-
ic controlled engine mount (deter-
mined by ECM according to the 
input signals) is indicated.
• IDLE: Engine speed is below 950 

rpm

• TRVL: Engine speed is above 950 

rpm

FUEL PUMP RLY

On/Off

Indicates the fuel pump relay control 
condition determined by ECM ac-
cording to the input signals.

VENT CONT/V

On/Off

The control condition of the EVAP 
canister vent control valve (deter-
mined by ECM according to the in-
put signals) is indicated.
• 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.

A/F S1 HTR(B2)

%

• Air fuel ratio (A/F) sensor 1 heater 

control value computed by ECM 
according to the input signals.

• The current flow to the heater be-

comes larger as the value increas-
es.

Monitored item

Unit

Monitor Item Selec-

tion

Description

Remarks

ECU IN-

PUT SIG-

NALS

MAIN-

SIG-

NALS