Nissan Pathfinder (2008 year). Manual - part 547

INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION

SEC-9

< FUNCTION DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

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FUNCTION DIAGNOSIS

INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION

System Diagram

INFOID:0000000001689509

System Description

INFOID:0000000001689510

INPUT/OUTPUT SIGNAL CHART

Intelligent Key Unit

IPDM E/R

BCM

SYSTEM DESCRIPTION 

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

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

Switch/Input signal

Input signal to

Intelligent Key unit 

Intelligent Key unit 

function

Actuator/Output signal

Key switch

Mechanical key 
(insert/remove)

Engine start function

• KEY warning lamp/buzzer
• Steering lock unit
• Starter relay request (to IPDM E/R)
• Inside key antenna

(Instrument panel, center console, 
luggage compartment)

• Key interlock solenoid

Ignition knob switch

Ignition knob
(push/release)

Steering lock unit

Steering lock 
(lock/unlock)

Inside key antenna
(Front and rear center console, over-
head console, luggage compartment)

Intelligent key
(inside antenna detection 
area or not.)

Switch/Input signal

Input signal to

IPDM E/R 

IPDM E/R function

Actuator/Output signal

Park/neutral position switch

P, N range

Engine start function

• Starter relay
• Starter motor

Switch/Input signal

Input signal to

BCM 

BCM function

Actuator/Output signal

Key switch

Brake 
(press/release)

Engine start function

• Inside key antenna

(Instrument panel, center console, 
luggage compartment)

ALKIA1267GB

SEC-10

< FUNCTION DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION

• Intelligent Key has 2 IDs (for Intelligent Key and for NATS). It can perform the door lock/unlock operation and

the engine start 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

mechanical key set in the Intelligent Key to the ignition key cylinder. At that time, perform the NATS ID verifi-
cation. If it is used when the Intelligent Key is carried, perform the Intelligent Key ID verification.

• If the ID is successfully verified, and when the ignition knob switch is pressed, steering lock will be released

and initiating the engine will be possible.

• The door lock/unlock operation can be performed when the Intelligent Key battery is discharged, by operat-

ing the driver door key cylinder using the mechanical key set in the Intelligent Key. 

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

NOTE:
• Refer to 

SEC-20, "COMMON ITEM : CONSULT-III Function (BCM - COMMON ITEM)"

 for any functions

other than engine start function of Intelligent Key system.

PRECAUTIONS FOR INTELLIGENT KEY SYSTEM

• For vehicles equipped with the Intelligent Key system, the transponder [the chip for NATS ID verifi-

cation] is integrated into the Intelligent Key. Therefore, the Intelligent Key alone is capable of provid-
ing security clearance for the engine to start. Also, when the mechanical key alone is inserted into
the key cylinder, performs the NATS ID verification to allow the engine to start. For vehicles without
Intelligent Key system, the transponder is integrated into the mechanical key which must be inserted
into the key cylinder to perform the NATS ID verification to allow the engine to start.

OPERATION WHEN INTELLIGENT KEY IS CARRIED

1.

When the ignition knob switch is ON, the Intelligent Key unit 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 Intelligent
Key unit.

3.

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

4.

Intelligent Key unit transmits the steering lock/unlock signal to steering lock unit if the verification results
are OK. For detail of key warning lamp operation, refer to 

SEC-17, "System Description"

.

5.

Release of the steering lock.

6.

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.

7.

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

8.

When shift position is in P or N position, battery power is supplied through the starter relay and operate
the starter motor and to start the cranking.

CAUTION:

If a malfunction is detected in the Intelligent Key system, the "NO KEY" warning message will be
displayed in the combination meter. At that time, the engine cannot be started.

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 MECHANICAL KEY IS USED

When the Intelligent Key battery is discharged, performs the NATS ID verification between the integrated tran-
sponder and BCM by inserting the mechanical key into the key cylinder, and then the engine can be started.
For details relating to starting the engine using mechanical key, refer to 

SEC-13, "System Description"

.

STEERING LOCK OPERATION

Steering is locked by steering lock unit when ignition switch is in the LOCK position (the ignition knob is
released) and key switch is OFF (key is removed from ignition key cylinder).

INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION

SEC-11

< FUNCTION DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

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Component Parts Location

INFOID:0000000001689511

ALKIA1268ZZ

1.

BCM M18, M19, M20
(view with instrument panel LH removed)

2.

Intelligent Key unit M164 
(view with glove box removed)

3.

IPDM E/R 
E119, E120, E122, E124

4.

ECM E16

5.

Key switch and ignition knob switch M66
(view with steering column removed)

6.

Steering lock solenoid M65

7.

Remote keyless entry receiver M67
(view with instrument panel RH removed)

8.

A/T device (detention switch key) M156
(view with center console removed)

9.

Inside key antenna 1 (instrument 
panel) M68
(view with center console removed)

SEC-12

< FUNCTION DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION

Component Description

INFOID:0000000001689512

10. Inside key antenna 3 (center console) 

M212
(view with center console removed)

11. Inside key antenna 2 (luggage compart-

ment) B129

(behind 3

rd

 row seat)

12. Intelligent Key warning buzzer E60

13. Combination meter M24

14. Vehicle security indicator lamp

Item

Function

Intelligent Key unit

Receives lock/unlock signal from remote keyless entry receiver, and then transmits to BCM.

BCM

Verifies the received signal from Intelligent Key, then informs ECM whether to allow engine start.

Remote keyless entry receiver

Receives lock/unlock signal from the Intelligent Key, and then transmits to Intelligent Key unit.

Intelligent Key

Transmits button operation to remote keyless entry receiver.

Steering lock solenoid

Locks the steering wheel when the ignition key is off and the Intelligent Key is outside the vehicle.

Inside key antenna

Detects if Intelligent Key is inside the vehicle. 

Intelligent Key warning buzzer

Warns the user of the lock/unlock condition and inappropriate operations with the buzzer sound.

A/T device (detention key switch)

Detects whether the shift lever is in park.

NVIS (NISSAN VEHICLE IMMOBILIZER SYSTEM-NATS)

SEC-13

< FUNCTION DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

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NVIS (NISSAN VEHICLE IMMOBILIZER SYSTEM-NATS)

System Diagram

INFOID:0000000001689513

System Description

INFOID:0000000001689514

INPUT/OUTPUT SIGNAL CHART

Intelligent Key Unit

BCM

SYSTEM DESCRIPTION

NATS (Nissan Anti-Theft System) has the following immobilizer functions:
• Engine immobilizer shows high anti-theft performance to prevent engine from starting by other than the

owner.

• Only a key with key ID registered in BCM and ECM can start engine, and shows high anti-theft performance

to prevent key from being copied or stolen.

• Security indicator always flashes with mechanical key removed condition (key switch: OFF) and ignition

knob released condition on LOCK position (ignition knob switch: OFF). 

• Therefore, NATS warns outsiders that the vehicle is equipped with the anti-theft system. Refer to 

SEC-17,

"System Description"

.

• If system detects malfunction, security indicator illuminates when ignition switch is turned to ON position.
• If the owner requires, ignition key ID or mechanical key ID can be registered for up to 4 keys.
• During trouble diagnosis or when the following parts have been replaced, and if mechanical key is added,

registration* is required. 

*1

: All keys kept by the owner of the vehicle should be registered with mechanical key.

- ECM
- BCM

LIIA2537E

Switch/Input signal

Input signal to BCM

BCM function

Actuator/Output signal

Ignition knob switch

Ignition knob
(push/release)

NATS

• Steering lock unit

Key switch

Mechanical key
(Insert/remove)

Steering lock unit

Steering
(lock/unlock)

ECM

Engine status signal

Switch/Input signal

Input signal to BCM

BCM function

Actuator/Output signal

NATS antenna amp.

Key ID

NATS

• Security indicator lamp
• Starter request

ECM

Engine status signal

SEC-14

< FUNCTION DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

NVIS (NISSAN VEHICLE IMMOBILIZER SYSTEM-NATS)

- Mechanical key
- Intelligent Key unit
- Remote keyless entry receiver
- Steering lock solenoid
• NATS trouble diagnosis, system initialization and additional registration of other mechanical key IDs must be

carried out using CONSULT-III.
When NATS initialization has been completed, the ID of the inserted mechanical key or mechanical key IDs
can be carried out.

• Possible symptom of NATS malfunction is “Engine cannot start”. Identify the possible causes according to

“Work Flow”, Refer to 

SEC-5, "Work Flow"

.

• If ECM other than Genuine NISSAN is installed, the engine cannot be started. For ECM replacement proce-

dure, refer to 

SEC-8, "ECM RE-COMMUNICATING FUNCTION : Description"

.

PRECAUTIONS FOR KEY REGISTRATION

• The key registration is a procedure that erases the current NATS ID once, and then re-registers a new ID.

Therefore the registered Intelligent Key is necessary for this procedure. Before starting the registration oper-
ation collect all registered Intelligent Keys from the customer.

• The NATS ID registration is the procedure that registers the ID stored into the transponder (integrated in

mechanical key) to BCM.
The Intelligent Key ID registration is the procedure that registers the ID to Intelligent Key unit.

• When performing the Intelligent Key system registration only, the engine cannot be started by inserting the

key into the key cylinder. When performing the NATS registration only, the engine cannot be started by using
the mechanical key.

SECURITY INDICATOR

• Always flashes with ignition knob released (ignition knob switch: LOCK) condition on ignition knob LOCK

position. 

• Always flashes with ignition knob released (ignition knob switch: LOCK) condition on mechanical key

removed position. 

MAINTENANCE INFORMATION

CAUTION:

It is necessary to perform NATS ID registration when replacing any of the following part.
If it's not (or fail to do so), the electrical system may not operate properly.

• Intelligent Key unit 
• BCM
• ECM
• Mechanical key
• Steering lock solenoid
• NATS antenna amp.

NVIS (NISSAN VEHICLE IMMOBILIZER SYSTEM-NATS)

SEC-15

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[WITH INTELLIGENT KEY SYSTEM]

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Component Parts Location

INFOID:0000000001689515

Component Description

INFOID:0000000001689516

1.

Key switch and ignition knob switch 
M66

2.

Steering lock solenoid M65
(view with steering column removed)

3.

Remote keyless entry receiver M67
(view with glove box removed)

4.

BCM M18, M20
(view with instrument panel LH re-
moved)

5.

Intelligent Key unit M164
(view with glove box removed)

6.

ECM E16

7.

IPDM E/R E119, E120, E122, E124
(view with cover removed)

8.

NATS antenna amp. M21

9.

Combination meter M24

10.

Security indicator lamp

ALKIA1269ZZ

Item

Function

Intelligent Key unit

Receives lock/unlock signal from remote keyless entry receiver, and then transmits to BCM.

BCM

Controls the door lock function and room lamp function.

Remote keyless entry receiver

Receives lock/unlock signal from the Intelligent Key, and then transmits to Intelligent Key unit.

Intelligent Key

Transmits button operation to remote keyless entry receiver.

Steering lock solenoid

Locks the steering wheel when the ignition key is off and the Intelligent Key is outside the vehicle.

Inside key antenna

Detects if Intelligent Key is inside the vehicle. 

SEC-16

< FUNCTION DIAGNOSIS >

[WITH INTELLIGENT KEY SYSTEM]

NVIS (NISSAN VEHICLE IMMOBILIZER SYSTEM-NATS)

Intelligent Key warning buzzer

Warns the user of the lock/unlock condition and inappropriate operations with the buzzer sound.

A/T device (detention key switch)

Detects whether the shift lever is in park.

Ignition knob switch

Monitors the status of the ignition knob switch.

NATS antenna amp.

Detects the mechanical key presence in the ignition key cylinder.

Security indicator

Indicates the status of the security system.

IPDM E/R

Monitors the ignition switch and the park switch signal from the TCM.

Item

Function