Infiniti FX35, FX50 (S51). Manual - part 1649

INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION

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[INTELLIGENT KEY SYSTEM]

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SYSTEM DESCRIPTION

INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION

System Diagram

INFOID:0000000005249398

System Description

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• The engine start function of Intelligent Key system is a system that makes it possible to start and stop the

engine without removing the key. It verifies the electronic ID using two-way communication when pressing
the push-button ignition switch while carrying the Intelligent Key, which operates based on the results of
electronic ID verification for Intelligent Key using two-way communication between the Intelligent Key and
the vehicle.
NOTE:
The driver should carry the Intelligent Key at all times.

• Intelligent Key has 2 IDs [for Intelligent Key and for IVIS (NATS)]. It can perform the door lock/unlock opera-

tion and the push-button ignition switch operation when the registered Intelligent Key is carried.

• When the Intelligent Key battery is discharged, it can be used as emergency back-up by inserting the Intelli-

gent Key in the key slot. At that time, perform the IVIS (NATS) ID verification. If it is used when the Intelligent
Key is carried, perform the Intelligent Key ID verification.

• If the ID is successfully verified, and when push-button ignition switch is pressed, steering lock will be

released and initiating the engine will be possible.

• If the door lock/unlock operation is performed when the Intelligent Key battery is discharged, all doors lock/

unlock can be performed by operating the driver door key cylinder using the mechanical key set in the Intel-
ligent Key. 

• Up to 4 Intelligent Keys can be registered (Including the standard Intelligent Key) on request from the owner.

NOTE:
Refer to 

DLK-16, "INTELLIGENT KEY SYSTEM : System Description"

 for any functions other than engine

start function of Intelligent Key system.

PRECAUTIONS FOR INTELLIGENT KEY SYSTEM

• In the Intelligent Key system, the transponder [the chip for IVIS (NATS) ID verification] is integrated

into the Intelligent Key. (For the conventional models, it is integrated into the mechanical key.) There-
fore, the mechanical key cannot perform the ID verification, and thus it cannot start the engine.
Instead, the IVIS (NATS) ID verification can be performed by inserting the Intelligent Key into the key
slot, and then it can start the engine.

OPERATION WHEN INTELLIGENT KEY IS CARRIED

1.

When the push-button ignition switch is pressed, the BCM signals the inside key antenna and transmits
the request signal to the Intelligent Key.

2.

The Intelligent Key receives the request signal and transmits the Intelligent Key ID signal to the BCM via
the remote keyless entry receiver.

3.

The Intelligent Key receives the Intelligent Key ID signal and verifies it with the registered ID.

JMKIA2503GB

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[INTELLIGENT KEY SYSTEM]

INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION

4.

BCM transmits the steering lock unlock signal to steering lock unit and IPDM E/R if the verification results
are OK.

5.

IPDM E/R turns the steering lock relay ON and supplies power to the steering lock unit.

6.

Release of the steering lock.

7.

BCM transmits the power supply stop signal to IPDM E/R when it confirms that the steering lock is in the
unlock condition.

8.

IPDM E/R turns the steering lock relay OFF and stops power supply to the steering lock unit.

9.

BCM turns ACC relay ON and transmits the ignition power supply ON signal to IPDM E/R.

10. IPDM E/R turns the ignition relay ON and starts the ignition power supply.
11. BCM confirms that the shift position is P or N.

12. BCM transmits the starter request signal via CAN communication to IPDM E/R and turns the starter relay

in IPDM E/R ON if BCM judges that the engine start condition is satisfied.

13. IPDM E/R turns the starter control relay ON when receiving the starter request signal.

14. Battery power is supplied through the starter relay and the starter control relay to operate the starter motor

and to start the cranking.

CAUTION:

If a malfunction is detected in the Intelligent Key system, the “KEY” warning lamp in the combina-
tion meter illuminates. At that time, the engine cannot be started.

15. When BCM receives feedback signal from ECM acknowledging the engine has been initiated, the BCM

transmits a stop signal to IPDM E/R and stops the cranking by turning OFF the starter motor relay. (If the
engine initiating has failed, the cranking will stop automatically within 5 seconds.)

CAUTION:

When the Intelligent Key is carried outside of the vehicle (inside key antenna detection area) with
the power supply in the ACC or ON position, even if the engine start condition* is satisfied, the
engine cannot be started.

*: For the engine start condition, refer to “PUSH-BUTTON IGNITION SWITCH OPERATION PROCEDURE”.

OPERATION RANGE

Engine can be started when Intelligent Key is inside the vehicle. However, sometimes engine might not start
when Intelligent Key is on instrument panel or in glove box.

OPERATION WHEN KEY SLOT IS USED

When the Intelligent Key battery is discharged, it performs the IVIS (NATS) ID verification between the inte-
grated transponder and BCM by inserting the Intelligent Key into the key slot, and then the engine can be
started.
For details relating to starting the engine using key slot, refer to 

SEC-15, "System Description"

.

BATTERY SAVER SYSTEM

When all the following conditions are met for 60 minutes, the battery saver system will cut off the power supply
to prevent battery discharge.
• The ignition switch is in the ACC position
• All doors are closed
• Selector lever is in the P position

Reset Condition of Battery Saver System

If any of the following conditions are met the battery saver system is released and the steering will change
automatically to the lock position from the OFF position.
• Opening any door
• Operating with request switch on door lock
• Operating with Intelligent Key on door lock
Pressing the push-button ignition switch and ignition switch will change the ignition switch to ACC position
from OFF position.

STEERING LOCK OPERATION

Steering is locked by steering lock unit when ignition switch is in the OFF position, selector lever is in the P
position and any of the following conditions are met.
• Opening door
• Closing door
• Door is locked with request switch
• Door is locked with Intelligent Key

INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION

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PUSH-BUTTON IGNITION SWITCH OPERATION PROCEDURE

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

Operation Enable Condition

• When an Intelligent Key is within the detection area of inside key antenna and when it is inserted to the key

slot, it is equivalent to the operations below.

• When starting the engine, the BCM monitors the following engine start conditions,
- Brake pedal operating condition
- Selector lever position
- Vehicle speed
• Unless each start condition is fulfilled, the engine will not respond regardless of how many times the engine

switch is pressed. At that time, illumination repeats the position in the order of LOCK

→

ACC

→

ON

→

OFF.

Operation Condition

*1: When the selector lever position is in the N position, the engine start condition is different according to the vehicle speed.

• At a vehicle speed of less than 4 km/h (2.5 MPH), the engine can start only when the brake pedal is depressed.

• At a vehicle speed of 4 km/h (2.5 MPH) or more, the engine can start even if the brake pedal is not depressed. (It is the same as

“Engine stall return operation while driving”.)

*2: When the selector lever position is in any position other than the P position and when the vehicle speed is 5 km/h (3.1 MPH) or more,
the engine stop condition is different.

• Press and hold the push-button ignition switch for 2 seconds or more. (When the push-button ignition switch is pressed for too short a

time, the operation may be invalid, so properly press and hold to prevent an incorrect operation.)

• Press the push-button ignition switch 3 times or more within 1.5 seconds. (Emergency stop operation)

Power supply position

Engine start/stop condition

Push-button ignition switch op-

eration frequency

Brake pedal

Selector lever position

LOCK 

→

 ACC

Not depressed

Any position

1

LOCK 

→

 ACC 

→

 ON

Not depressed

Any position

2

LOCK 

→

 ACC 

→

 ON 

→

 

OFF

Not depressed

Any position

3

LOCK 

→

 START

ACC 

→

 START

ON 

→

 START

(Engine start)

Depressed

P or N position (*1)

1

[If the switch is pressed once, 

the engine starts from any pow-
er supply position (LOCK, ACC, 

and ON)]

Engine is running 

→

 

OFF
(Engine stop)

—

P position

1

Engine is running 

→

 

ACC
(Engine stop)

—

Any position other than P (*2)

1

Engine stall return oper-
ation while driving

—

N position

1

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[INTELLIGENT KEY SYSTEM]

INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION

Component Parts Location

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1.

BCM M118, M119, M121, M122, 
M123

2.

IPDM E/R E5, E6, E7

3.

ECM
VQ engine: M107
VK engine: M160

4.

A/T assembly connector F51

5.

TCM (built in A/T assembly) F151

6.

Push-button ignition switch M50

JMKIA2674ZZ