System Description

SYSTEM DIAGRAM 

Courtesy of NISSAN NORTH AMERICA, INC.

SYSTEM DESCRIPTION 

• The INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS [IVIS (NATS)] prevents the engine from being started by Intelligent Key whose ID is not registered to the vehicle (BCM). It has higher protection against auto theft involving the duplication of mechanical keys.
• The ignition key integrated in the Intelligent Key cannot start the engine. When the Intelligent Key battery is discharged, the IVIS (NATS) ID verification is performed between the transponder integrated with Intelligent Key and BCM via NATS antenna amp. when the Intelligent Key backside is contacted to push-button ignition switch. If the verification results are OK, the engine start operation can be performed by the push-button ignition switch operation.
• Locate the security indicator lamp and apply the anti-theft system equipment sticker that warns that the IVIS (NATS) is on board the model.
• Security indicator lamp always blinks when the power supply position is any position other than ON.
• Up to 4 Intelligent Keys can be registered (including the standard ignition key) upon request from the owner.
• Specified registration is required when replacing ECM, BCM or Intelligent Key.
• Possible symptom of IVIS (NATS) malfunction is "Engine cannot start". The engine can not be started because of other than IVIS (NATS) malfunction, so start the trouble diagnosis. Refer to Work Flow .
• If ECM other than genuine part is installed, the engine cannot be started. For ECM replacement procedure, Refer to Work Procedure .

PRECAUTIONS FOR KEY REGISTRATION 

• The ID registration is a procedure that erases the current IVIS (NATS) ID once, and then reregisters a new ID. Therefore before starting the registration operation, collect all registered Intelligent Keys from the customer.
• When registering the Intelligent Key, perform only one procedure to simultaneously register both ID [IVIS (NATS) ID and Intelligent Key ID].

SECURITY INDICATOR LAMP 

• Warns that the vehicle is equipped with IVIS (NATS).
• Security indicator lamp always blinks when the power supply position is any position other than ON.
  NOTE: Because security indicator lamp is highly efficient, the battery is barely affected.

ENGINE START OPERATION WHEN INTELLIGENT KEY IS CONTACTED TO PUSH-BUTTON IGNITION SWITCH 

1. When brake pedal is depressed while selector lever is in the P position, BCM activates NATS antenna amp. that is located behind push-button ignition switch.
2. When Intelligent Key (transponder built-in) backside is contacted to push-button ignition switch, BCM starts IVIS (NATS) ID verification between BCM and Intelligent Key (transponder built-in) via NATS antenna amp.
3. When the IVIS (NATS) ID verification result is OK, buzzer in combination meter sounds and BCM transmits the result to ECM.
4. BCM turns ACC relay ON and transmits ignition power supply ON signal to IPDM E/R.
5. IPDM E/R turns the ignition relay ON and starts the ignition power supply.
6. BCM detects that the selector lever position is P or N.
7. BCM transmits starter request signal to IPDM E/R and turns the starter relay in IPDM E/R ON if BCM judges that the engine start condition* is satisfied.
8. IPDM E/R turns the starter control relay ON when receiving the starter request signal.
9. Power supply is supplied through the starter relay and the starter control relay to operate the starter motor.
10. When BCM receives feedback signal from ECM indicating that the engine is started, BCM transmits a stop signal to IPDM E/R and stops cranking by turning off the starter motor relay. (If engine start is unsuccessful, cranking stops automatically within 5 seconds.)

*: For the engine start condition, refer to "POWER SUPPLY POSITION CHANGE TABLE BY PUSH-BUTTON IGNITION SWITCH OPERATION" below.

POWER SUPPLY POSITION CHANGE TABLE BY PUSH-BUTTON IGNITION SWITCH OPERATION 

The power supply position changing operation can be performed with the following operations.

Vehicle speed: less than 4 km/h (2.5 MPH) 

Power supply position	Engine start/stop condition		Push-button ignition switch operation frequency
	Selector lever	Brake pedal operation condition
LOCK → ACC	-	Not depressed	1
LOCK → ACC → ON	-	Not depressed	2
LOCK → ACC → ON → OFF	-	Not depressed	3
LOCK → START ACC → START ON → START	P or N position	Depressed	1
Engine is running → OFF	-	-	1

Vehicle speed: 4 km/h (2.5 MPH) or more 

Power supply position	Engine start/stop condition		Push-button ignition switch operation frequency
	Selector lever	Brake pedal operation condition
Engine is running → ACC	-	-	Emergency stop operation
Engine stall return operation while driving	N position	Not depressed	1

Emergency stop operation

• Press and hold the push-button ignition switch for 2 seconds or more.
• Press the push-button ignition switch 3 times or more within 1.5 seconds.