Content .. 333 334 335 336 ..

Infiniti M45 (Y34). Manual - part 335

ENGINE CONTROL SYSTEM

EC-29

●

At idle

●

At low battery voltage

●

During acceleration

The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.

Nissan Torque Demand (NTD) Control System

ABS002VW

INPUT/OUTPUT SIGNAL CHART

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

SYSTEM DESCRIPTION

NTD control system decides the target traction based on the accelerator operation status and the current driv-
ing condition. It then selects the engine torque target by correcting running resistance and atmospheric pres-
sure, and controlling the power-train. Using electric throttle control actuator, it achieves the engine torque
development target which corresponds linearly to the driver's accelerator operation.
Running resistance correction control compares the engine torque estimate value, measured vehicle acceler-
ation, and running resistance on a flat road, and estimates vehicle weight gain and running resistance varia-
tion caused by slopes to correct the engine torque estimate value.
Atmospheric pressure correction control compares the engine torque estimate value from the airflow rate and
the target engine torque for the target traction, and estimates variation of atmospheric pressure to correct the
target engine torque. This system achieves powerful driving without reducing engine performance in the prac-
tical speed range in mountains and high-altitude areas.

Sensor

Input signal to ECM

ECM function

Actuator

Camshaft position sensor (PHASE)

Engine speed

NTD control

Electric throttle con-
trol actuator and fuel
injector

Crankshaft position sensor (POS)

Mass air flow sensor

Amount of intake air

Engine coolant temperature sensor

Engine coolant temperature

Throttle position sensor

Throttle position

Accelerator pedal position sensor

Accelerator pedal position

Park/Neutral position (PNP) switch

Gear position

Power steering pressure sensor

Power steering operation

Battery

Battery voltage

TCM*

A/T control signal

Air conditioner switch*

Air conditioner operation

VDC/TCS/ABS control unit*

VDC/TCS/ABS operation

Wheel sensor*

Vehicle speed

Electrical load*

Electrical load signal

EC-30

ENGINE CONTROL SYSTEM

Air Conditioning Cut Control

ABS002D6

INPUT/OUTPUT SIGNAL CHART

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

SYSTEM DESCRIPTION

This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned OFF.

●

When the accelerator pedal is fully depressed.

●

When cranking the engine.

●

At high engine speeds.

●

When the engine coolant temperature becomes excessively high.

●

When operating power steering during low engine speed or low vehicle speed.

●

When engine speed is excessively low.

●

When refrigerant pressure is excessively low or high.

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

ABS002D7

INPUT/OUTPUT SIGNAL CHART

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

SYSTEM DESCRIPTION

If the engine speed is above 1,400 rpm under no load (for example, the selector lever 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 var-
ies based on engine speed.
Fuel cut will be operated until the engine speed reaches 1,000 rpm, then fuel cut will be cancelled.

NOTE:
This function is different from deceleration control listed under Multiport Fuel Injection (MFI) System,

EC-26

CAN Communication

ABS002D8

SYSTEM DESCRIPTION

CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.

Sensor

Input Signal to ECM

ECM function

Actuator

Air conditioner switch*

Air conditioner ON signal

Air conditioner
cut control

Air conditioner relay

Throttle position sensor

Throttle position

Accelerator pedal position sensor

Accelerator pedal position

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

Engine speed

Engine coolant temperature sensor

Engine coolant temperature

Ignition switch

Start signal

Refrigerant pressure sensor

Refrigerant pressure

Power steering pressure sensor

Power steering operation

Wheel sensor*

Vehicle speed

Sensor

Input Signal to ECM

ECM function

Actuator

Park/neutral position (PNP) switch

Neutral position

Fuel cut con-
trol

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

ENGINE CONTROL SYSTEM

EC-31

Each control unit transmits/receives data but selectively reads required data only. Refer to

LAN-21, "CAN

Communication Unit"

, about CAN communication for detail.

EC-32

BASIC SERVICE PROCEDURE

PFP:00018

Idle Speed and Ignition Timing Check

ABS002D9

IDLE SPEED

With CONSULT-II

Check idle speed in “DATA MONITOR” mode with CONSULT-II.

With GST

Check idle speed with GST.

IGNITION TIMING

Any of following two methods may be used.

Method A

Attach timing light to loop wire as shown.

Check ignition timing.

Method B

Remove No. 1 ignition coil.

SEF058Y

PBIB0139E

PBIB1116E

Content .. 333 334 335 336 ..