Nissan Sentra Service Manual: Engine control system

Nissan Sentra Service Manual / Engine / Engine control system / System / Engine control system

ENGINE CONTROL SYSTEM : System Description

SYSTEM DIAGRAM

NOTE:

NOTE:

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.

Function	Reference
Fuel injection control	EC-35, "MULTIPORT FUEL INJECTION SYSTEM : System Description"
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 Description"
Intake manifold runner control	EC-43, "INTAKE MANIFOLD RUNNER CONTROL : System Description"
Intake manifold tuning control	EC-43, "INTAKE MANIFOLD TUNING SYSTEM : System Description"
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 Description"
Air conditioning cut control	EC-46, "AIR CONDITIONING CUT CONTROL : System Description"
Cooling fan control	EC-47, "COOLING FAN CONTROL : System Description"
Starter motor drive control	EC-48, "STARTER MOTOR DRIVE CONTROL : System Description"
Evaporative emission	EC-49, "EVAPORATIVE EMISSION SYSTEM : System Description"
Automatic speed control	EC-51, "AUTOMATIC SPEED CONTROL DEVICE (ASCD) : System 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"

ENGINE CONTROL SYSTEM : Fail Safe

NON DTC RELATED ITEM

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, "Component Function Check"

DTC RELATED ITEM

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 mode		Vehicle behavior
Traveling control mode	Accelerator angle 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 reference position. The intake manifold runner control valve motor is turned OFF (intake manifold runner control valve opens).

Fail Safe Pattern

Fail Safe List

Fail Safe List

Multiport fuel injection system

System

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Multiport fuel injection system

MULTIPORT FUEL INJECTION SYSTEM : System Description SYSTEM DIAGRAM *1: ECM determines the start signal status by the signals of engine speed and battery voltage. *2: M/T models *3: CVT mod ...

Other materials:

P0850 PNP Switch
Description For CVT models, transmission range switch is turn ON when the selector lever is P or N. For M/T models, park/neutral position (PNP) range switch is ON when the selector lever is Neutral position. ECM detects the position because the continuity of the line (the ON) exists. DTC ...

General Precautions
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 connector, turn ignition switch OFF and disconnect negative battery cable. Failure to do so may damage the ECM because ...

System description
System Can communication system Can communication system : system description CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle multiplex communication line with high data communication speed and excellent error detection ability. Man ...