Nissan Frontier. Manual - part 596

ENGINE CONTROL SYSTEM SYMPTOMS

EC-955

< SYMPTOM DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

1 - 6: The numbers refer to the order of inspection.
(continued on next page)

SYSTEM — ENGINE MECHANICAL & OTHER

Knock sensor circuit

2

3

EC-737

Crankshaft position sensor (POS) circuit

2

2

EC-740

Camshaft position sensor (PHASE) circuit

3

2

EC-743

Vehicle speed signal circuit

2

3

3

3

EC-814

Power steering pressure sensor circuit

2

3

3

EC-822

ECM

2

2

3

3

3

3

3

3

3

3

3

EC-825

, 

EC-827

Intake valve timing control solenoid valve cir-
cuit

3

2

1

3

2

2

3

3

EC-630

PNP signal circuit

3

3

3

3

3

EC-833

VIAS control solenoid valve circuit

1

EC-873

Refrigerant pressure sensor circuit

2

3

3

4

EC-947

Electrical load signal circuit

3

EC-926

Air  conditioner  circuit

2

2

3

3

3

3

3

3

3

3

2

HAC-142

, 

HAC-208

ABS actuator and electric unit (control unit)

4

BRC-8

, 

BRC-120

SYMPTOM

Reference 
page

HARD/NO S

TA

R

T/RES

TA

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

LOW/NO RETU

RN 

T

O ID

LE

OVERHEA

T

S

/W

A

TER TEMPERA

T

URE HIG

H

E

XCESSIVE

 FUEL CON

S

UMP

T

ION

E

XCESSIVE

 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-956

< SYMPTOM DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

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

NTING

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-141

Air cleaner

EM-141

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

5

5

5

5

EM-141

Electric throttle control actuator

EM-142

Air leakage from intake manifold/
Collector/Gasket

EM-142

, 

EM-145

Cranking

Battery

1

1

1

1

1

1

1

1

PG-4

Generator circuit

CHG-2

, 

CHG-5

Starter circuit

3

STR-6

, 

STR-10

Signal plate

6

EM-230

PNP switch (M/T)
TCM (A/T)

4

TM-170

Engine

Cylinder head

5

5

5

5

5

5

5

5

EM-211

Cylinder head gasket

4

3

Cylinder block

6

6

6

6

6

6

6

6

4

EM-230

Piston

Piston ring

Connecting rod

Bearing

Crankshaft

ENGINE CONTROL SYSTEM SYMPTOMS

EC-957

< SYMPTOM DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

C

D

E

F

G

H

I

J

K

L

M

A

EC

N

P

O

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

Valve 
mecha-
nism

Timing chain

5

5

5

5

5

5

5

5

EM-176

Camshaft

EM-193

Intake valve timing control

EM-205

Intake valve

3

EM-211

Exhaust valve

Exhaust

Exhaust manifold/Tube/Muffler/
Gasket

5

5

5

5

5

5

5

5

EM-148

, 

EX-4

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-151

, 

LU-27

, 

LU-

30

, 

Oil level (Low)/Filthy oil

LU-22

Cooling

Radiator/Hose/Radiator filler cap

5

5

5

5

5

5

5

4

5

CO-39

Thermostat

5

CO-55

Water pump

CO-50

Water gallery

CO-57

Cooling fan

5

CO-47

Coolant level (Low)/Contaminat-
ed coolant

5

CO-39

NVIS (NISSAN Vehicle Immobilizer System — 
NATS)

1

1

SEC-3

SYMPTOM

Reference 
page

HARD/NO S

TA

R

T/RES

TA

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

LOW/NO RETU

RN 

T

O ID

LE

OVERHEA

T

S

/W

A

TER TEMPERA

T

URE HIG

H

E

XCESSIVE

 FUEL CON

S

UMP

T

ION

E

XCESSIVE

 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-958

< SYMPTOM DIAGNOSIS >

[VQ40DE FOR USA AND CANADA]

NORMAL OPERATING CONDITION

NORMAL OPERATING CONDITION

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

INFOID:0000000009481656

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-488, "System Description"

.

Sensor

Input Signal to ECM

ECM function

Actuator

Park/neutral position (PNP) switch (M/T)
TCM (A/T)

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*