2009 INFINITI QX56 ECU

SEC-1
BODY EXTERIOR, DOORS, ROOF & VEHICLE SECURITY
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SECTION SEC
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CONTENTS
SECURITY CONTROL SYSTEM
WITH INTELLIGENT KEY SYSTEM
BASIC INSPECTION ....... .............................
3
DIAGNOSIS AND REPAIR WORKFLOW ..... .....3
Work Flow ........................................................... ......3
INSPECTION AND ADJUSTMENT .....................6
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT .................................................... ......
6
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT : Special Repair Requirement .......
6
ECM RE-COMMUNICATING FUNCTION ............. ......6
ECM RE-COMMUNICATING FUNCTION : De-
scription .....................................................................
6
ECM RE-COMMUNICATING FUNCTION : Spe-
cial Repair Requirement ............................................
6
FUNCTION DIAGNOSIS ...............................7
INTELLIGENT KEY SYSTEM/ENGINE
START FUNCTIO N ........................................ .....
7
System Diagram .................................................. ......7
System Description ...................................................7
Component Parts Location ........................................9
Component Description ...........................................10
INFINITI VEHICLE IMMOBILIZER SYSTEM-
NATS ..................................................................
11
System Diagram .................................................. ....11
System Description .................................................11
Component Parts Location ......................................13
Component Description ..........................................13
VEHICLE SECURITY SYSTEM .........................15
System Diagram .................................................. ....15
System Description .................................................15
Component Parts Location ......................................16
Component Description ...........................................17
DIAGNOSIS SYSTEM (BCM) ............................18
COMMON ITEM ..................................................... ....18
COMMON ITEM : CONSULT-III Function (BCM -
COMMON ITEM) .....................................................
18
IMMU ...................................................................... ....18
IMMU : CONSULT-III Function (BCM - IMMU) ........18
THEFT ALM ........................................................... ....19
THEFT ALM : CONSULT-III Function (BCM -
THEFT ALM) ....................................................... ....
19
DIAGNOSIS SYSTEM (INTELLIGENT KEY
UNIT) .................................................................
20
CONSULT-III Function (INTELLIGENT KEY) ..........20
COMPONENT DIAGNOSIS .........................22
U1000 CAN COMM CIRCUIT ...........................22
Description ........................................................... ....22
DTC Logic ................................................................22
Diagnosis Procedure ...............................................22
U1010 CONTROL UNIT (CAN) .........................23
Description ...............................................................23
DTC Logic ................................................................23
Diagnosis Procedure ...............................................23
Special Repair Requirement ....................................23
B2013 ID DISCORD I-KEY-STRG ....................24
Description ...............................................................24
DTC Logic ................................................................24
Diagnosis Procedure ...............................................24
B2190, P1614 NATS ANTENNA AMP. ............27
Description ...............................................................27
DTC Logic ................................................................27
Diagnosis Procedure ...............................................27
B2191, P1615 DIFFERENCE OF KEY .............30
Description ...............................................................30
DTC Logic ................................................................30
Diagnosis Procedure ...............................................30
Revision: December 20092009 QX56

SEC-2
B2192, P1611 ID DISCORD, IMMU-ECM .........31
Description ........................................................... ...31
DTC Logic ...............................................................31
Diagnosis Procedure ..............................................31
B2193, P1612 CHAIN OF ECM-IMMU ..............33
Description ........................................................... ...33
DTC Logic ...............................................................33
Diagnosis Procedure ..............................................33
B2194 ID DISCORD IMMU-I-KEY .....................34
Description ........................................................... ...34
DTC Logic ...............................................................34
Diagnosis Procedure ..............................................34
B2552 INTELLIGENT KEY ................................35
Description ........................................................... ...35
DTC Logic ...............................................................35
Diagnosis Procedure ..............................................35
Special Repair Requirement ...................................35
B2590 ID DISCORD BCM-I-KEY .................... ...36
Description ........................................................... ...36
DTC Logic ...............................................................36
Diagnosis Procedure ..............................................36
P1610 LOCK MODE ..........................................37
Description ........................................................... ...37
DTC Logic ...............................................................37
Diagnosis Procedure ..............................................37
POWER SUPPLY AND GROUND CIRCUIT .....38
INTELLIGENT KEY UNIT ...................................... ...38
INTELLIGENT KEY UNIT : Diagnosis Procedure ...38
BCM ........................................................................ ...38
BCM : Diagnosis Procedure ...................................38
KEY CYLINDER SWITCH .................................40
Description ........................................................... ...40
Component Function Check ...................................40
Diagnosis Procedure ..............................................40
IGNITION KNOB SWITCH .................................42
Ignition Knob Switch Check ................................. ...42
HOOD SWITCH .................................................44
Diagnosis Procedure ..............................................44
HORN FUNCTION .............................................46
Symptom Table ................................................... ...46
VEHICLE SECURITY INDICATOR ....................47
Description ........................................................... ...47
Component Function Check .................................47
Diagnosis Procedure ..............................................47
ECU DIAGNOSIS ..................................... ...49
BCM (BODY CONTROL MODULE) ............... ...49
Reference Value .................................................. ...49
Terminal Layout ......................................................51
Physical Values .......................................................51
Wiring Diagram - VEHICLE SECURITY SYSTEM ...57
Wiring Diagram - IVIS .............................................68
Fail Safe .................................................................76
DTC Inspection Priority Chart ...............................77
DTC Index ..............................................................77
INTELLIGENT KEY UNIT ..................................79
Reference Value - Intelligent Key Unit ................. ...79
Reference Value - Steering Lock Solenoid .............82
Wiring Diagram - INTELLIGENT KEY SYSTEM/
ENGINE START FUNCTION - ................................
83
Fail Safe .................................................................95
DTC Inspection Priority Chart ...............................95
DTC Index ..............................................................95
IPDM E/R (INTELLIGENT POWER DISTRI-
BUTION MODULE ENGINE ROOM) .................
96
Reference Value .................................................. ...96
Terminal Layout ......................................................98
Physical Values .......................................................98
Fail Safe ...............................................................102
DTC Index ............................................................103
SYMPTOM DIAGNOSIS ...........................104
INTELLIGENT KEY SYSTEM/ENGINE
START FUNCTION SYMPTOMS ................... ..
104
Symptom Table .................................................... .104
VEHICLE SECURITY SYSTEM SYMPTOMS ..105
Symptom Table .....................................................105
INFINITI VEHICLE IMMOBILIZER SYSTEM-
NATS SYMPTOMS ...........................................
106
Symptom Table .................................................... .106
ON-VEHICLE MAINTENANCE .................107
PRE-INSPECTION FOR DIAGNOSTIC ......... ..107
Basic Inspection ................................................... .107
Vehicle Security Operation Check ........................107
PRECAUTION ...........................................109
PRECAUTIONS .............................................. ..109
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" .............................................................. .
109
Precaution Necessary for Steering Wheel Rota-
tion After Battery Disconnect ................................
109
ON-VEHICLE REPAIR ..............................111
VEHICLE SECURITY SYSTEM ...................... ..111
Removal and Installation .......................................111
Revision: December 20092009 QX56

SEC-8
< 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 igniti on 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 DLK-21, "
INTELLIGENT KEY : System Description" for any functions other than engine start func-
tion 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 Inte lligent Key. Therefore, the Intellig ent 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 solenoid if the verification results are OK. For detail of key warning message operation, refer to DLK-38, "
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 “KEY” warning message will be dis-
played in the combination meter. At th at 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-11, "
System Description".
STEERING LOCK OPERATION
Steering is locked by steering lock solenoid 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).
Revision: December 20092009 QX56

SEC-10
< FUNCTION DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
INTELLIGENT KEY SYSTEM/ENGINE START FUNCTION
Component Description
INFOID:0000000003775871
10. Inside key antenna 1 (rear of center con- sole) M209 11. Inside key antenna 4 (overhead console
area) R210
(view with overhead console removed) 12. Inside key antenna 2 (luggage
compartment) B76
(view with rear carpet removed)
13. Intelligent Key warning buzzer E25 14. Combination meter M23, M24 15. 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 th e 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 shift selector (park position
switch) Detects whether the shift lever is in park.
Revision: December 20092009 QX56

INFINITI VEHICLE IMMOBILIZER SYSTEM-NATSSEC-11
< FUNCTION DIAGNOSIS > [WITH INTELLIGENT KEY SYSTEM]
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INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS
System DiagramINFOID:0000000003775872
System DescriptionINFOID:0000000003775873
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 posit ion (ignition knob switch: OFF).
• Therefore, NATS warns outsiders that the vehicl e is equipped with the anti-theft system. Refer to SEC-15,
"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 vehi cle 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 solenoid
Key switch
Mechanical key
(Insert/remove)
Steering lock solenoid Ste eri ng
(lock/unlock)
ECM Engine status signal
Switch/Input signalInput signal to BCM BCM function Actuator/Output signal
NATS antenna amp. Key ID
NATS• Security indicator lamp
• Starter request
ECM Engine status signal
Revision: December 20092009 QX56

SEC-12
< FUNCTION DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
INFINITI 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-3, "
Work Flow".
• If ECM other than Genuine NISSAN is installed, t he engine cannot be started. For ECM replacement proce-
dure, refer to SEC-6, "
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 fo r this procedure. Before starting the registration oper-
ation collect all registered Intelligent Keys from the customer.
• The NATS ID registration is the procedure that regi sters the ID stored into the transponder (integrated in
mechanical key) to BCM.
The Intelligent Key ID registration is the procedur e 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 LOCKposition.
• 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.
Revision: December 20092009 QX56

INFINITI VEHICLE IMMOBILIZER SYSTEM-NATSSEC-13
< FUNCTION DIAGNOSIS > [WITH INTELLIGENT KEY SYSTEM]
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Component Parts LocationINFOID:0000000003775874
Component DescriptionINFOID:0000000003775875
1. Key switch and ignition knob switch M12 2. Steering lock solenoid M15
(view with steering column removed) 3. Remote keyless entry receiver M25
(view with instrument panel RH re-
moved)
4. BCM M18, M20 (view with instrument panel LH re-
moved) 5. Intelligent Key unit M70
(view with instrument panel LH re-
moved) 6. ECM E16
7. IPDM E/R E119, E120, E122, E124 (view with co ver removed) 8. NATS antenna amp. M21
9. Combination meter M24
10. Security indicator lamp
ALKIA0959ZZ
Item Function
Intelligent Key unit Receives lock/unlock signal from re mote 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.
Revision: December 20092009 QX56

SEC-14
< FUNCTION DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS
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.
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
Revision: December 20092009 QX56