Nissan Sentra. Manual - part 334

EC-32

< SYSTEM DESCRIPTION >

[MRA8DE]

SYSTEM

SYSTEM

ENGINE CONTROL SYSTEM
ENGINE CONTROL SYSTEM : System Description

INFOID:0000000009758360

SYSTEM DIAGRAM

NOTE:

JSBIA3138GB

SYSTEM

EC-33

< SYSTEM DESCRIPTION >

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• Position switch and clutch pedal position switch are not used in models with CVT.

• ASCD steering switch and brake pedal position switch are used in models with ASCD.

• TCM and transmission range switch are not used in models with M/T.

SYSTEM DESCRIPTION

ECM controls the engine by various functions.

ENGINE CONTROL SYSTEM : Fail Safe

INFOID:0000000009758361

NON DTC RELATED ITEM

DTC RELATED ITEM

Function

Reference

Fuel injection control

EC-35, "MULTIPORT FUEL INJECTION SYSTEM : System De-
scription"

Electric ignition control

EC-38, "ELECTRIC IGNITION SYSTEM : System Description"

Intake valve timing control

EC-39, "INTAKE VALVE TIMING CONTROL : System Description"

Exhaust valve timing control

EC-41, "EXHAUST VALVE TIMING CONTROL : System Descrip-
tion"

Intake manifold runner control

EC-43, "INTAKE MANIFOLD RUNNER CONTROL : System De-
scription"

Intake manifold tuning control

EC-43, "INTAKE MANIFOLD TUNING SYSTEM : System Descrip-
tion"

Engine protection control (Low engine oil pressure)

EC-44, "ENGINE PROTECTION CONTROL AT LOW ENGINE 
OIL PRESSURE : System Description"

Fuel filler cap warning system

EC-45, "FUEL FILLER CAP WARNING SYSTEM : System De-
scription"

Air conditioning cut control

EC-46, "AIR CONDITIONING CUT CONTROL : System Descrip-
tion"

Cooling fan control

EC-47, "COOLING FAN CONTROL : System Description"

Starter motor drive control

EC-48, "STARTER MOTOR DRIVE CONTROL : System Descrip-
tion"

Evaporative emission

EC-49, "EVAPORATIVE EMISSION SYSTEM : System Descrip-
tion"

Automatic speed control

EC-51, "AUTOMATIC SPEED CONTROL DEVICE (ASCD) : Sys-
tem Description"

ECO mode control

•

DMS-6, "ECO MODE CONTROL : System Description"

 (M/T 

models)

•

DMS-26, "ECO MODE CONTROL : System Description"

 (CVT 

models)

SPORT mode control

•

DMS-6, "ECO MODE CONTROL : System Description"

 (M/T 

models)

•

DMS-63, "SPORT MODE CONTROL : System Description"

 

(CVT models)

CAN communication

EC-52, "CAN COMMUNICATION : System Description"

Detected 

items

Engine operating condition 

in fail-safe mode

Remarks

Reference page

Malfunction 
indicator 
circuit

Engine speed will not rise 
more than 2,500 rpm due 
to the fuel cut

When there is an open circuit on MIL circuit, the ECM cannot warn the 
driver by lighting up MIL when there is malfunction on engine control 
system.
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.

EC-467, "Compo-
nent Function 
Check"

EC-34

< SYSTEM DESCRIPTION >

[MRA8DE]

SYSTEM

Description

When a DTC is detected, ECM executes a mode (in the Fail-safe mode) applicable to the DTC. The fail-safe

mode has the preset traveling control mode (accelerator angle variation and engine output limit) and device fix

mode.

Fail Safe Pattern

Fail Safe List

×:Applicable —: Not applicable

Fail safe mode

Vehicle behavior

Traveling con-
trol mode

Accelerator an-
gle variation 
control

ECM controls the accelerator pedal depression speed to make it slower than actual speed. This 
causes a drop in accelerating performance and encourages the driver to repair malfunction.
NOTE:
ECM does not control the accelerator pedal releasing speed.

Engine output 
control

ECM reduces the engine output, according to the rise in engine speed. This reduces the vehicle 
speed to encourage the driver to repair malfunction.

Device fix mode

• This mode fixes the IVT control solenoid valve and the EVT control solenoid valve in the refer-

ence position.

• The intake manifold runner control valve motor is turned OFF (intake manifold runner control 

valve opens).

Pattern

Fail safe mode

A

Traveling control mode

Accelerator angle variation control

B

Engine output control

C

Device fix mode

DTC 

No.

Detected items

Vehicle behavior

Pattern

Others

A

B

C

P0011

Intake valve timing control

—

—

×

ECM activates the IVT intermediate lock control solenoid 
valve to bring the cam sprocket into an intermediate lock con-
dition.

P0075

Intake valve timing control

—

—

×

ECM activates the IVT intermediate lock control solenoid 
valve to bring the cam sprocket into an intermediate lock con-
dition.

P0014
P0078

Exhaust valve timing control

—

—

×

—

P0101
P0102
P0103

Mass air flow sensor circuit

×

×

×

—

P0122
P0123
P0222
P0223
P2135

Throttle position sensor

—

—

—

The ECM controls the electric throttle control actuator in reg-
ulating the throttle opening in order for the idle position to be 
within +10 degrees.
The ECM regulates the opening speed of the throttle valve to 
be slower than the normal condition.
So, the acceleration will be poor. 

P0117
P0118

Engine coolant temperature 
sensor

×

×

—

—

P0171
P0172

Fuel injection system

×

—

—

—

P0196
P0197
P0198

Engine oil temperature sensor

—

—

—

Exhaust valve timing control does not function.

SYSTEM

EC-35

< SYSTEM DESCRIPTION >

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MULTIPORT FUEL INJECTION SYSTEM
MULTIPORT FUEL INJECTION SYSTEM : System Description

INFOID:0000000009758362

SYSTEM DIAGRAM

P0300
P0301
P0302
P0303
P0304

Misfire

×

—

—

—

P0500

Vehicle speed sensor

×

—

—

—

P0524

Engine oil pressure

—

—

—

• ECM illuminates oil pressure warning lamp on the combina-

tion meter.

• Engine speed will not rise more than 4,000rpm due to the 

fuel cut.

• Fail-safe is canceled when ignition switch OFF 

→ ON.

P0603

ECM

×

×

—

—

P0605

ECM

×

×

—

—

P0643

Sensor power supply

—

—

—

ECM stops the electric throttle control actuator control, throttle 
valve is maintained at a fixed opening (approx. 5 degrees) by 
the return spring.

P1078

Exhaust valve timing control 
position sensor circuit

×

—

×

—

P1650
P1651

Starter relay

×

×

—

P1805

Brake switch

—

—

—

ECM controls the electric throttle control actuator by regulat-
ing the throttle opening to a small range.
Therefore, acceleration will be poor.

Vehicle condition

Driving condition

When engine is idling

Normal

When accelerating

Poor acceleration

P2004

Intake manifold runner control 
valve

—

×

×

—

P2100
P2103

Throttle control motor relay

—

—

—

ECM stops the electric throttle control actuator control, throttle 
valve is maintained at a fixed opening (approx. 5 degrees) by 
the return spring.

P2101

Electric throttle control func-
tion

—

—

—

ECM stops the electric throttle control actuator control, throttle 
valve is maintained at a fixed opening (approx. 5 degrees) by 
the return spring.

P2118

Throttle control motor

—

—

—

ECM stops the electric throttle control actuator control, throttle 
valve is maintained at a fixed opening (approx. 5 degrees) by 
the return spring.

P2119

Electric throttle control actua-
tor

×

×

—

—

P2122
P2123
P2127
P2128
P2138

Accelerator pedal position 
sensor

—

—

—

The ECM controls the electric throttle control actuator in reg-
ulating the throttle opening in order for the idle position to be 
within +10 degrees.
The ECM regulates the opening speed of the throttle valve to 
be slower than the normal condition.
So, the acceleration will be poor. 

DTC 

No.

Detected items

Vehicle behavior

Pattern

Others

A

B

C