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System Description

SYSTEM DIAGRAM 

INPUT/OUTPUT SIGNAL CHART 

Input/Output Transmits/Receives component Signal name Description
Input Accelerator pedal position sensor Accelerator pedal position sensor signal Detects an accelerator pedal position.
Brake pedal position switch signal Detects the brake pedal is depressed.
Crankshaft position sensor signal Detects an engine speed.
Engine coolant temperature sensor signal Detects an engine coolant temperature.
Atmospheric pressure sensor signal Detects an atmospheric pressure.
Transmission malfunction signal Detects Transmission is malfunction.
Battery discharging current Receives battery discharging current, battery current and battery temperature.
Battery current
Start/Stop OFF switch (ON/OFF) Receives an operational state of the start/stop OFF switch (ON/OFF).
Driver assistance buzzer signal Receives vehicle detection condition of detection zone.
IPDM E/R CAN communication Start/Stop permit signal Detects the transmission is ready to operate the idle start/stop system.
Hood switch signal Detects engine hood status.
BCM CAN communication Ignition switch status signal Detects ignition switch status.
Stop lamp switch signal Detects an accelerator pedal position.
Door switch signal Detects the status of driver side door.
I-key exist information signal Detects the i-key exist
ABS actuator and electric unit (control unit) CAN communication Vehicle speed signal Detects vehicle speed.
Brake fluid pressure sensor signal Detects brake fluid pressure.
Brake booster pressure sensor signal Detects a pressure in brake booster.
ABS operation signal Detects ABS operation.
VDC operation signal Detects VDC operation.
Brake hold readiness signal Detects the brake hold readiness status judged by the ABS actuator and electric unit (control unit).
G sensor signal Detects vehicle angularity.
A/C auto amp. CAN communication Start/Stop permit signal Detects the air conditioning system is ready to operate the idle start/stop system.
Combination meter CAN communication Seat belt buckle switch signal Detects driver is sitting on the driver seat.
TCM CAN communication Start/Stop permit signal Detects the transmission is ready to operate the idle start/stop system.
Shift position signal Detects the transmission is ready to operate the idle start/stop system.
Tow mode switch Detects Tow mode switch status.
Input DC/DC converter LIN communication Operation status signal Detects an operational state of DC/DC converter.
Diagnosis signal Detects DC/DC converter malfunction.
Output BCM CAN communication Start/Stop status signal Transmits a start/stop status signal
ABS actuator and electric unit (control unit) CAN communication Start/Stop status signal Transmits a start/stop status signal
Brake hold request signal Transmits the brake hold/release request according to the idle start/stop system.
A/C auto amp. CAN communication Start/Stop status signal Transmits a start/stop status signal
TCM CAN communication Start/Stop status signal Transmits a start/stop status signal
Combination meter CAN communication Start/Stop status signal Transmits a start/stop status signal
Start/Stop indicator lamp request signal Transmits request signal which turn ON the start/stop indicator lamp.
DC/DC converter LIN communication DC/DC converter operation check signal Checks DC/DC converter operation status.
DC/DC voltage request signal Controls the DC/DC output voltage.
Around view monitor control unit CAN communication Start/Stop status signal Transmits a start/stop status signal
Cranking enable signal Transmits a cranking enable signal to activates the starter motor control relay.

SYSTEM DESCRIPTION 

The idle start/stop system enables the engine to automatically stop/restart with a simple operation and reduces unnecessary idling during stoplight or traffic congestion to improve fuel economy, reduce exhaust gas, and minimize noise. ECM detects a vehicle condition, engine condition and driver's operation condition based on signals sent from each unit and the sensors to comprehensively control the idle start/stop system. The operation condition of the idle start/stop system is indicated by the start/stop indicator lamp on the combination meter and showing on the information display (dot matrix information display). (Refer to Warning lamps/Indicator lamps.) If a malfunction is detected in the idle start/stop system, the system control is automatically deactivated and the malfunction is alerted to the driver by blinking the start/stop indicator lamp and showing the status on the information display (dot matrix information display). When a driver's operation is judged as dangerous one during the idle start/stop system operation, the start/stop indicator lamp blinks at a high speed and the status is shown on the information display (with dot matrix information display). The buzzer mounted on the combination meter sounds simultaneously to warn the driver of the dangerous operation. ECM detects a vehicle condition, engine condition and driver's operation condition based on signals sent from each unit and the sensors to comprehensively control the idle start/stop system. The operation condition of the idle start/stop system is indicated by the start/stop indicator lamp on the combination meter and showing on the information display (dot matrix information display). (Refer to Warning lamps/Indicator lamps ). If a malfunction is detected in the idle start/stop system, the system control is automatically deactivated and the malfunction is alerted to the driver by blinking the start/stop indicator lamp and showing the status on the information display (dot matrix information display). When a driver's operation is judged as dangerous one during the idle start/stop system operation, the start/stop indicator lamp blinks at a high speed and the status is shown on the information display (with dot matrix information display). The buzzer mounted on the combination meter sounds simultaneously to warn the driver of the dangerous operation.

SYSTEM CONTROL CONDITION DISPLAY 

Start/Stop indicator lamp status 

System condition Condition Start/Stop indicator lamp Warning chime
Operate Normal Illuminate -
Hood open * High speed blinking Sound
Normal operation: Idle start/stop system inhibited state System conditions excluded failure are not satisfied. (Battery state of charge, A/C steering operation, driver's seat belt is unbuckled etc.) Illuminate -

*: Engine is stalled after alert for 1.5 seconds.

BASIC OPERATION 

FUNCTION DESCRIPTION 

When the idle start/stop system readiness conditions are satisfied while the vehicle is moving, the system is ready. When the idle start/stop system operation conditions are satisfied while the vehicle is in a stop condition, the engine is stopped. During idle start/stop system operation, stopping time, the amount of fuel saved by the idle start/stop system is indicated on the combination meter. When the engine restart conditions are satisfied, ECM activates the engine restart relay to restart the engine. And the DC/DC converter boosts the voltage during cranking to protect the electrical equipment from low voltage. After restarting the engine, the start/stop indicator lamp and the indication on the information display turn OFF.

Start/Stop Readiness Condition 

ECM judges idle start/stop system is ready when the following conditions are satisfied.

Item Condition
Vehicle Start/Stop OFF switch OFF (Switch indicator: OFF)
Start/Stop indicator Lamp Not blink (No malfunction)
Door (driver side) Close
Seat belt (driver side) Fastened
Driving history Drive the vehicle at 6 km/h (3.7 MPH) or more after start the engine with ignition switch
Drive the vehicle at 8 km/h (5 MPH) or more after restart
NOTE: SYMBOL When shift the selector lever R to D, drive the vehicle at 10 km/h (6.3 MPH) or more.
Passes 5 seconds or more after restart
Hood Close
Air conditioning Automatic air conditioning Not in DEF mode
Receives start/stop permit signal
Manual air conditioning Not in DEF mode
ABS System is normal
ABS not activated *2
Receives start/stop permit signal
Battery status Not poor battery performance.
Elevation 2, 500 m (8, 203 ft)
Intelligent parking assist OFF
Engine Gear Position D position
I-key I-key exists inside vehicle
ST RLY operation status Relay operates correctly
Starter motor No starter motor long continuous operation
Delivery mode Not in delivery mode *2
Brake booster pressure Presence of sufficient negative pressure to a brake force. (Refer to System Description.) System Description ).
Stand Still Activation Receives start/stop permit signal.
Drive mode switch Not in Tow mode.
MIL (Malfunction indicator lamp) Not illuminate (No malfunction)
Engine coolant temperature 40 - 100 °C (104 -212 °F)

*1: Depends on the vehicle conditions.

*2: If ABS system is activated, drive the vehicle at 12 km/h (7.5 MPH) or more after stop the vehicle.

CAUTION:
  • The idle start/stop system may be cancelled when the battery is weak or if a battery other than the idle start/stop system specific battery is used.
  • Even though the vehicle is in above conditions, the idle start/stop system may be cancelled automatically.

Start/Stop Operation Condition 

When the following conditions are satisfied, ECM stops the engine. And the combination meter turns ON a start/stop indicator lamp.

Item Condition
Vehicle Vehicle speed Vehicle stopped [0 km/h (0 MPH) ]
Steering wheel Not steer (steering force does not occur)
Brake pedal Depressed
Brake fluid pressure 0.8 MPa (8 bar, 8.16 kg/cm2, 160 psi)
Brake booster pressure Presence of sufficient negative pressure to a brake force
Vehicle angularity Approx. 14% or less
Engine Engine speed Around idle speed (Approx. 1, 130 RPM or less)
Engine system Permit start/stop operation
Transmission Selector lever position D
Transmission system Receives start/stop permit signal

Restart Condition 

When any of the following conditions is satisfied during idle start/stop system operating condition, ECM restarts the engine. And the combination meter turns OFF the start/stop indicator lamp.

Item Condition
Start/Stop OFF switch ON (Switch indicator ON)
Vehicle Steering wheel Steered (steering force occurs)
Door (driver side) Open
Seat belt Released
I-key I-key doesn't exist inside vehicle
Air conditioning Automatic air conditioning DEF switch is pressed.
Air conditioning system cannot keep the performance.
Manual air conditioning Select DEF mode and fan is ON
Brake Brake booster pressure Insufficient negative pressure for braking force
Brake pedal Released
Accelerator pedal Depressed
Engine Engine coolant temperature less than 40°C (104°F), over than 100°C (212°F)
Engine system Inhibit start/stop operation
Trans mission Shift lever position Except for D position
Battery Poor battery performance
ABS Receives start/stop operation
Intelligent Parking Assist
Emergency brake
Drive mode switch Selected the TOW mode

Engine stalled Condition 

When any of the following conditions is satisfied during idle start/stop system operating condition, ECM stalls the engine.

Item Condition
Vehicle Hood Open
NOTE: SYMBOL
  • The engine may restart automatically if required by the Idling Stop System.
  • Place the Ignition switch in the "OFF" position before opening the hood or performing any maintenance. Failure to do so may result in serious injuries due to automatic engine restart.
  • Always place the Ignition switch in the "OFF" position before leaving your vehicle, as the system may have turned the engine off, but the Ignition will still be on and automatic restart may occur.

VOLTAGE STABILIZER FUNCTION 

ECM transmits a voltage stabilizer signal to the DC/DC converter during cranking at an engine restart. The DC/DC converter temporarily increases the voltage to prevent the electric equipment from reset due to low voltage. The adoption of the DC/DC converter enables a stable power supply to the electric equipment connected to the DC/DC converter and permits a substantial lowering of the voltage. For the electrical equipment connected to the DC/DC converter, see "SYSTEM DIAGRAM".

NOTE: SYMBOL The brightness of the head lamps may be changed due to the voltage reduction at an engine restart because they are not connected to the DC/DC converter.

ENGINE RESTART BYPASS RELAY CONTROL 

ECM controls the engine restart bypass control relay and activates the engine restart bypass relay. When the restart conditions are satisfied, ECM turns ON the engine restart bypass control relay instantaneously right after the restart and opens the engine restart bypass relay. This allows a current to pass the inner resistance circuit right after the starter motor is activated. When the starter motor is rotating, the voltage is directly supplied to the starter motor without being passed through the inner resistance circuit in the engine restart bypass relay because the engine restart bypass relay is closed. In this way, ECM enables the battery voltage stabilization and reduces the battery deterioration rate by decreasing the battery voltage drop resulted from cranking at an engine restart.

GNSDB135939Courtesy of NISSAN NORTH AMERICA, INC.
GNSDB134679Courtesy of NISSAN NORTH AMERICA, INC.