Nissan Pathfinder (2008 year). Manual - part 294

ECM

EC-469

< ECU DIAGNOSIS >

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1.

If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.

2.

Perform 

TM-33

. (The DTC in TCM will be erased.)

3.

Select Service $04 with GST (Generic Scan Tool).

 No Tools

NOTE:
If the DTC is not for A/T related items (see 

EC-453, "DTC Index"

), skip step 2.

1.

If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once.
Wait at least 10 seconds and then turn it ON (engine stopped) again.

2.

Perform 

TM-33

. (The DTC in TCM will be erased.)

3.

Change the diagnostic test mode from Mode II to Mode I by depressing the accelerator pedal. Refer to

EC-66, "Malfunction Indicator Lamp (MIL)"

.

• If the battery is disconnected, the emission-related diagnostic information will be lost within 24

hours.

• The following data are 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
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.

EC-470

< SYMPTOM DIAGNOSIS >

[VQ40DE]

ENGINE CONTROL SYSTEM SYMPTOMS

SYMPTOM DIAGNOSIS

ENGINE CONTROL SYSTEM SYMPTOMS

Symptom Matrix Chart

INFOID:0000000001366462

SYSTEM — BASIC ENGINE CONTROL SYSTEM

SYMPTOM

Reference 
page

HARD/NO ST

AR

T

/REST

AR

T

 (EXCP

. 

H

A

)

ENGINE ST

ALL

HESIT

A

TION/SURGING/FLA

T

 SPOT

SP

ARK KNOCK/DET

O

NA

TION

LACK

 OF POWER/

POOR 

ACC

E

LERA

TION

HIGH IDL

E

/LOW

 IDLE

ROUG

H IDLE/HUNTING

IDLI

NG VIBRA

T

ION

SLOW/NO RETURN T

O

 IDLE

OVERHEA

T

S/W

A

TER TEMPERA

T

UR

E

 HIGH

EXCESS

IVE F

U

E

L

 CONSUMP

T

IO

N

EXCESS

IVE OIL CONSUMP

T

ION

BA

TTER

Y

 DEAD (UNDER CHARGE)

Warranty symptom code

AA

AB

AC

AD

AE

AF

AG

AH

AJ

AK

AL

AM

HA

Fuel

Fuel  pump  circuit

1

1

2

3

2

2

2

3

2

EC-396

Fuel  pressure  regulator  system

3

3

4

4

4

4

4

4

4

4

EC-481

Fuel  injector  circuit

1

1

2

3

2

2

2

2

EC-392

Evaporative  emission  system

3

3

4

4

4

4

4

4

4

4

EC-46

Air

Positive crankcase ventilation sys-
tem

3

3

4

4

4

4

4

4

4

4

1

EC-410

Incorrect idle speed adjustment

1

1

1

1

1

EC-20

Electric  throttle  control  actuator

1

1

2

3

3

2

2

2

2

2

2

EC-355

, 

EC-361

Ignition

Incorrect  ignition  timing  adjustment

3

3

1

1

1

1

1

1

EC-20

Ignition  circuit

1

1

2

2

2

2

2

2

EC-400

Power  supply  and  ground  circuit

2

2

3

3

3

3

3

2

3

EC-93

Mass air flow sensor circuit

1

1

2

2

2

2

2

2

EC-112

, 

EC-118

Engine coolant temperature sensor circuit

3

3

3

EC-126

, 

EC-134

Air fuel ratio (A/F) sensor 1

EC-142
EC-146
EC-150
EC-154
EC-378

Throttle position sensor circuit

2

2

EC-130

, 

EC-197

, 

EC-312

, 

EC-314

, 

EC-370

Accelerator pedal position sensor circuit

3

2

1

EC-93

, 

EC-

363

, 

EC-

366

, 

EC-

374

ENGINE CONTROL SYSTEM SYMPTOMS

EC-471

< SYMPTOM DIAGNOSIS >

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1 - 6: The numbers refer to the order of inspection.

(continued on next page)

SYSTEM — ENGINE MECHANICAL & OTHER

Knock sensor circuit

2

3

EC-208

Crankshaft position sensor (POS) circuit

2

2

EC-211

Camshaft position sensor (PHASE) circuit

3

2

EC-215

Vehicle speed signal circuit

2

3

3

3

EC-286

Power steering pressure sensor circuit

2

3

3

EC-292

ECM

2

2

3

3

3

3

3

3

3

3

3

EC-295

, 

EC-297

Intake valve timing control solenoid valve cir-
cuit

3

2

1

3

2

2

3

3

EC-109

PNP switch circuit

3

3

3

3

3

EC-302

VIAS control solenoid valve circuit

1

EC-346

Refrigerant pressure sensor circuit

2

3

3

4

EC-412

Electrical load signal circuit

3

EC-390

Air  conditioner  circuit

2

2

3

3

3

3

3

3

3

3

2

HAC-106

, 

HAC-171

ABS actuator and electric unit (control unit)

4

BRC-7

, 

BRC-127

SYMPTOM

Reference 
page

HARD/NO S

T

A

R

T/RES

T

A

R

T (E

XCP

. HA)

E

N

GINE

 ST

ALL

HES

IT

A

TION/SURGING/FLA

T

 SPOT

S

P

ARK KNOC

K

/DET

O

NA

TI

ON

LACK OF 

POWER/POOR ACCELERA

TION

HIG

H

 IDL

E

/L

OW

 ID

LE

ROUGH IDLE/HUNTING

ID

LING VI

BRA

T

ION

S

L

OW/NO RETU

RN 

T

O

 ID

LE

OVERHEA

T

S

/W

A

TER TEMPERA

T

URE HIG

H

E

X

CESSIVE

 FUEL CON

S

UMP

T

ION

E

X

CESSIVE

 OIL 

C

O

NSUMP

T

ION

B

A

TTER

Y 

DEAD (UNDER CHARGE)

Warranty symptom code

AA

AB

AC

AD

AE

AF

AG

AH

AJ

AK

AL

AM

HA

EC-472

< SYMPTOM DIAGNOSIS >

[VQ40DE]

ENGINE CONTROL SYSTEM SYMPTOMS

SYMPTOM

Reference 
page

HARD/NO ST

AR

T/REST

AR

T (EXCP

. 

HA)

E

N

GI

N

E

 ST

AL

L

HESIT

A

TION/S

U

R

GING/F

LA

T SP

OT

SP

ARK KNOCK/DE

T

O

NA

TION

LACK OF POWE

R/POOR

 ACCELERA

TIO

N

HIGH IDL

E

/L

OW

 IDL

E

ROUG

H IDLE/HU

N

TING

IDL

ING VIBRA

T

ION

SLO

W

/NO RETURN T

O

 IDLE

OVERHEA

T

S/W

A

TE

R

 TEMPERA

T

URE 

HIGH

EXCES

SIVE F

U

EL CONSUMP

T

ION

EXCES

SIVE OI

L CONSUMP

T

IO

N

BA

TTE

R

Y

 DEAD (UN

D

E

R

 CH

A

R

GE)

Warranty symptom code

AA

AB

AC

AD

AE

AF

AG

AH

AJ

AK

AL

AM

HA

Fuel

Fuel tank

5

5

FL-6

Fuel piping

5

5

5

5

5

5

FL-5

Vapor lock

—

Valve deposit

5

5

5

5

5

5

5

—

Poor fuel (Heavy weight gasoline, 
Low octane)

—

Air

Air duct

5

5

5

5

5

5

EM-25

Air cleaner

EM-25

Air leakage from air duct
(Mass air flow sensor — electric 
throttle control actuator)

5

5

5

5

EM-25

Electric throttle control actuator

EM-26

Air leakage from intake manifold/
Collector/Gasket

EM-26

, 

EM-29

Cranking

Battery

1

1

1

1

1

1

1

1

PG-6

Generator circuit

CHG-4

Starter circuit

3

STR-4

Signal plate

6

EM-117

PNP switch

4

TM-50

Engine

Cylinder head

5

5

5

5

5

5

5

5

EM-98

Cylinder head gasket

4

3

Cylinder block

6

6

6

6

6

6

6

6

4

EM-117

Piston

Piston ring

Connecting rod

Bearing

Crankshaft

Valve 
mecha-
nism

Timing chain

5

5

5

5

5

5

5

5

EM-61

Camshaft

EM-81

Intake valve timing control

EM-61

Intake valve

3

EM-98

Exhaust valve

ENGINE CONTROL SYSTEM SYMPTOMS

EC-473

< SYMPTOM DIAGNOSIS >

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Exhaust

Exhaust manifold/Tube/Muffler/
Gasket

5

5

5

5

5

5

5

5

EM-93

, 

EM-31

Three way catalyst

Lubrica-
tion

Oil pan/Oil strainer/Oil pump/Oil 
filter/Oil gallery/Oil cooler

5

5

5

5

5

5

5

5

EM-36

, 

EM-117

, 

LU-11

, 

LU-

7

Oil level (Low)/Filthy oil

LU-8

Cooling

Radiator/Hose/Radiator filler cap

5

5

5

5

5

5

5

4

5

CO-11

Thermostat

5

CO-26

Water pump

CO-22

Water gallery

CO-28

Cooling fan

5

CO-19

Coolant level (Low)/Contaminat-
ed coolant

5

CO-11

NVIS (NISSAN Vehicle Immobilizer System — 
NATS)

1

1

SEC-5

 or 

SEC-97

SYMPTOM

Reference 
page

HARD/NO S

T

A

R

T/RES

T

A

R

T (E

XCP

. HA)

E

N

GINE

 ST

ALL

HES

IT

A

TION/SURGING/FLA

T

 SPOT

S

P

ARK KNOC

K

/DET

O

NA

TI

ON

LACK OF 

POWER/POOR ACCELERA

TION

HIG

H

 IDL

E

/L

OW

 ID

LE

ROUGH IDLE/HUNTING

ID

LING VI

BRA

T

ION

S

L

OW/NO RETU

RN 

T

O

 ID

LE

OVERHEA

T

S

/W

A

TER TEMPERA

T

URE HIG

H

E

X

CESSIVE

 FUEL CON

S

UMP

T

ION

E

X

CESSIVE

 OIL 

C

O

NSUMP

T

ION

B

A

TTER

Y 

DEAD (UNDER CHARGE)

Warranty symptom code

AA

AB

AC

AD

AE

AF

AG

AH

AJ

AK

AL

AM

HA

EC-474

< SYMPTOM DIAGNOSIS >

[VQ40DE]

NORMAL OPERATING CONDITION

NORMAL OPERATING CONDITION

Fuel Cut Control (at No Load and High Engine Speed)

INFOID:0000000001366290

INPUT/OUTPUT SIGNAL CHART

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

SYSTEM DESCRIPTION

If the engine speed is above 1,800 rpm under no load (for example, the shift position is neutral and engine
speed is over 1,800 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies
based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,500 rpm, then fuel cut will be cancelled.
NOTE:
This function is different from deceleration control listed under 

EC-37, "System Description"

.

Sensor

Input Signal to ECM

ECM function

Actuator

Park/neutral position (PNP) switch

Neutral position

Fuel cut control

Fuel injector

Accelerator pedal position sensor

Accelerator pedal position

Engine coolant temperature sensor

Engine coolant temperature

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

Engine speed

Wheel sensor

Vehicle speed*

PRECAUTIONS

EC-475

< PRECAUTION >

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PRECAUTION

PRECAUTIONS

Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT 
PRE-TENSIONER"

INFOID:0000000001366281

The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.

WARNING:

• To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death in

the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.

• Improper maintenance, including incorrect removal and installation of the SRS, can lead to personal

injury caused by unintentional activation of the system. For removal of Spiral Cable and Air Bag
Module, see the SRS section.

• Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this

Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or har-
ness connectors.

Precaution for Procedure without Cowl Top Cover

INFOID:0000000001366282

When performing the procedure after removing cowl top cover, cover
the lower end of windshield with urethane, etc.

On Board Diagnosis (OBD) System of Engine and A/T

INFOID:0000000001366283

The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.

CAUTION:

• Be sure to turn the ignition switch OFF and disconnect the negative battery cable before any repair

or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc. will
cause the MIL to light up.

• Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will

cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)

• Certain systems and components, especially those related to OBD, may use a new style slide-lock-

ing type harness connector. For description and how to disconnect, refer to 

PG-62

.

• Be sure to route and secure the harnesses properly after work. The interference of the harness with

a bracket, etc. may cause the MIL to light up due to the short circuit.

• Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube

may cause the MIL to light up due to the malfunction of the EVAP system or fuel injection system,
etc.

• Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM and

TCM (Transmission control module) before returning the vehicle to the customer.

PIIB3706J

EC-476

< PRECAUTION >

[VQ40DE]

PRECAUTIONS

Precaution

INFOID:0000000001366284

• Always use a 12 volt battery as power source.
• Do not attempt to disconnect battery cables while engine is

running.

• Before connecting or disconnecting the ECM harness con-

nector, turn ignition switch OFF and disconnect negative bat-
tery cable. Failure to do so may damage the ECM because
battery voltage is applied to ECM even if ignition switch is
turned OFF.

• Before removing parts, turn ignition switch OFF and then dis-

connect negative battery cable.

• Do not disassemble ECM.
• If a battery cable is disconnected, the memory will return to the ECM value.

The ECM will now start to self-control at its initial value. Engine operation can vary slightly when the
terminal is disconnected. However, this is not an indication of a malfunction. Do not replace parts
because of a slight variation.

• If the battery is disconnected, the following emission-related diagnostic information will be lost

within 24 hours.

- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
- <Frexible Fuel Vehicle>

Presumed ethanol mixture ratio

• When connecting ECM harness connector, fasten it securely

with levers as far as they will go as shown in the figure.

• When connecting or disconnecting pin connectors into or

from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM pin
terminal, when connecting pin connectors.

• Securely connect ECM harness connectors.

A poor connection can cause an extremely high (surge) volt-
age to develop in coil and condenser, thus resulting in dam-
age to ICs.

• Keep engine control system harness at least 10 cm (4 in) away

from adjacent harness, to prevent engine control system mal-
functions due to receiving external noise, degraded operation
of ICs, etc.

• Keep engine control system parts and harness dry.

SEF289H

PBIB1512E

PBIB0090E