2011 INFINITI QX56 ECU

SEC-2
WIRING DIAGRAM .....................................31
SECURITY CONTROL SYSTEM .................... ...31
Wiring Diagram .................................................... ...31
BASIC INSPECTION ...................................48
DIAGNOSIS AND REPAIR WORK FLOW ..... ...48
Work Flow ............................................................ ...48
ADDITIONAL SERVICE WHEN REPLACING
CONTROL UNIT ................................................
51
ECM ........................................................................ ...51
ECM : Description ...................................................51
ECM : Work Procedure ...........................................51
BCM ........................................................................ ...51
BCM : Description ...................................................51
BCM : Work Procedure ...........................................51
DTC/CIRCUIT DIAGNOSIS ...................... ...53
P1610 LOCK MODE ....................................... ...53
Description ........................................................... ...53
DTC Logic ...............................................................53
Diagnosis Procedure ..............................................53
P1611 ID DISCORD, IMMU-ECM ......................54
DTC Logic ............................................................ ...54
Diagnosis Procedure ..............................................54
P1612 CHAIN OF ECM-IMMU ...........................55
DTC Logic ............................................................ ...55
Diagnosis Procedure ..............................................55
P1614 CHAIN OF IMMU-KEY ...........................56
DTC Logic ............................................................ ...56
Diagnosis Procedure ..............................................56
B2192 ID DISCORD, IMMU-ECM ......................60
DTC Logic ............................................................ ...60
Diagnosis Procedure ..............................................60
B2193 CHAIN OF ECM-IMMU ...........................61
DTC Logic ............................................................ ...61
Diagnosis Procedure ..............................................61
B2195 ANTI-SCANNING ...................................62
DTC Logic ............................................................ ...62
Diagnosis Procedure ..............................................62
B2196 DONGLE UNIT .......................................63
Description ........................................................... ...63
DTC Logic ...............................................................63
Diagnosis Procedure ..............................................63
B2198 NATS ANTENNA AMP. .........................65
DTC Logic ............................................................ ...65
Diagnosis Procedure ..............................................65
B2013 STEERING LOCK UNIT .........................69
DTC Logic ............................................................ ...69
Diagnosis Procedure ............................................ ...69
B2014 CHAIN OF STRG-IMMU ........................70
DTC Logic ............................................................ ...70
Diagnosis Procedure ...............................................70
B2555 STOP LAMP ...........................................73
DTC Logic ............................................................ ...73
Diagnosis Procedure ...............................................73
Component Inspection ............................................74
B2556 PUSH-BUTTON IGNITION SWITCH .....76
DTC Logic ............................................................ ...76
Diagnosis Procedure ...............................................76
Component Inspection ............................................77
B2557 VEHICLE SPEED ...................................78
DTC Logic ............................................................ ...78
Diagnosis Procedure ...............................................78
B2601 SHIFT POSITION ...................................79
DTC Logic ............................................................ ...79
Diagnosis Procedure ...............................................79
Component Inspection ............................................81
B2602 SHIFT POSITION ...................................82
DTC Logic ............................................................ ...82
Diagnosis Procedure ...............................................82
Component Inspection ............................................83
B2603 SHIFT POSITION ...................................85
DTC Logic ............................................................ ...85
Diagnosis Procedure ...............................................85
Component Inspection ............................................87
B2604 SHIFT POSITION ...................................89
DTC Logic ............................................................ ...89
Diagnosis Procedure ...............................................89
B2605 SHIFT POSITION ...................................91
DTC Logic ............................................................ ...91
Diagnosis Procedure ...............................................91
B2608 STARTER RELAY .................................93
DTC Logic ............................................................ ...93
Diagnosis Procedure ...............................................93
B2609 STEERING STATUS ..............................95
DTC Logic ............................................................ ...95
Diagnosis Procedure ...............................................95
B260B STEERING LOCK UNIT ........................98
DTC Logic ............................................................ ...98
Diagnosis Procedure ...............................................98
B260C STEERING LOCK UNIT ........................99
DTC Logic ............................................................ ...99
Diagnosis Procedure ...............................................99
B260D STEERING LOCK UNIT .......................100
DTC Logic ............................................................ .100
Diagnosis Procedure .............................................100
Revision: 2010 May2011 QX56

SEC-3
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B260F ENGINE STATUS ............................... ..101
Description .......................................................... ..101
DTC Logic .............................................................101
Diagnosis Procedure .............................................101
B2612 STEERING STATUS .............................102
DTC Logic ........................................................... ..102
Diagnosis Procedure .............................................102
B2619 BCM ......................................................105
DTC Logic ........................................................... ..105
Diagnosis Procedure .............................................105
B26E9 STEERING STATUS ............................106
DTC Logic ........................................................... ..106
Diagnosis Procedure .............................................106
B26EF STEERING LOCK RELAY ...................107
DTC Logic ........................................................... ..107
Diagnosis Procedure .............................................107
B26F0 STEERING LOCK RELAY ...................109
DTC Logic ........................................................... ..109
Diagnosis Procedure .............................................109
B26F3 STARTER CONTROL RELAY .............111
DTC Logic ........................................................... ..111
Diagnosis Procedure .............................................111
B26F4 STARTER CONTROL RELAY .............112
DTC Logic ........................................................... ..112
Diagnosis Procedure .............................................112
B26F5 STEERING LOCK STATUS SWITCH ..113
DTC Logic .............................................................113
Diagnosis Procedure .............................................113
B26F7 BCM ......................................................116
DTC Logic ........................................................... ..116
Diagnosis Procedure .............................................116
B26F8 BCM ......................................................117
DTC Logic ........................................................... ..117
Diagnosis Procedure .............................................117
B26F9 CRANKING REQUEST CIRCUIT .........118
DTC Logic ........................................................... ..118
Diagnosis Procedure .............................................118
B26FA CRANKING REQUEST CIRCUIT ........120
DTC Logic ........................................................... ..120
Diagnosis Procedure .............................................120
B26FC KEY REGISTRATION ..........................122
DTC Logic ........................................................... ..122
Diagnosis Procedure .............................................122
B209F CRANKING REQUEST CIRCUIT .........123
DTC Logic ........................................................... ..123
Diagnosis Procedure .............................................123
B20A0 CRANKING REQUEST CIRCUIT .......125
DTC Logic ............................................................ ..125
Diagnosis Procedure .............................................125
B2108 STEERING LOCK RELAY ..................127
DTC Logic ..............................................................127
Diagnosis Procedure .............................................127
B2109 STEERING LOCK RELAY ..................128
DTC Logic ..............................................................128
Diagnosis Procedure .............................................128
B210A STEERING LOCK UNIT ......................129
DTC Logic ..............................................................129
Diagnosis Procedure .............................................129
B210B STARTER CONTROL RELAY ............131
DTC Logic ..............................................................131
Diagnosis Procedure .............................................131
B210C STARTER CONTROL RELAY ............132
DTC Logic ..............................................................132
Diagnosis Procedure .............................................132
B210D STARTER RELAY ..............................133
DTC Logic ..............................................................133
Diagnosis Procedure .............................................133
B210E STARTER RELAY ...............................134
DTC Logic ..............................................................134
Diagnosis Procedure .............................................134
B210F SHIFT POSITION/CLUTCH INTER-
LOCK SWITCH ...............................................
136
DTC Logic ..............................................................136
Diagnosis Procedure .............................................136
B2110 SHIFT POSITION/CLUTCH INTER-
LOCK SWITCH ...............................................
138
DTC Logic ..............................................................138
Diagnosis Procedure .............................................138
HEADLAMP FUNCTION .................................140
Component Function Check ..................................140
Diagnosis Procedure .............................................140
HOOD SWITCH ...............................................141
Component Function Check ................................141
Diagnosis Procedure ............................................141
Component Inspection ...........................................142
HORN FUNCTION ...........................................143
Component Function Check .............................. ..143
Diagnosis Procedure ............................................143
Component Inspection ...........................................145
SECURITY INDICATOR LAMP ......................146
Component Function Check ................................146
Diagnosis Procedure .............................................146
SYMPTOM DIAGNOSIS ............................148
Revision: 2010 May2011 QX56

SEC-4
ENGINE DOES NOT START WHEN INTELLI-
GENT KEY IS INSIDE OF VEHICLE ...............
148
Description ........................................................... ..148
Diagnosis Procedure .............................................148
STEERING DOES NOT LOCK ........................149
Description ........................................................... ..149
Diagnosis Procedure .............................................149
SECURITY INDICATOR LAMP DOES NOT
TURN ON OR BLINK .......................................
150
Description ........................................................... ..150
Diagnosis Procedure .............................................150
VEHICLE SECURITY SYSTEM CANNOT BE
SET ..................................................................
151
INTELLIGENT KEY ................................................ ..151
INTELLIGENT KEY : Description ..........................151
INTELLIGENT KEY : Diagnosis Procedure ......... ..151
DOOR REQUEST SWITCH ................................... ..151
DOOR REQUEST SWITCH : Description .............151
DOOR REQUEST SWITCH : Diagnosis Proce-
dure ...................................................................... .
151
DOOR KEY CYLINDER ......................................... .152
DOOR KEY CYLINDER : Description ...................152
DOOR KEY CYLINDER : Dia gnosis Procedure .. .152
VEHICLE SECURITY ALARM DOES NOT
ACTIVATE ...................................................... ..
153
Description ........................................................... .153
Diagnosis Procedure .............................................153
PANIC ALARM FUNCTION DOES NOT OP-
ERATE ..............................................................
154
Description ........................................................... .154
Diagnosis Procedure .............................................154
REMOVAL AND INSTALLATION .............155
NATS ANTENNA AMP. .................................. ..155
Removal and Installation ...................................... .155
PUSH-BUTTON IGNITION SWITCH ................156
Exploded View ..................................................... .156
Removal and Installation .......................................156
Revision: 2010 May2011 QX56

SEC-8
< SYSTEM DESCRIPTION >[WITH INTELLIGENT KEY SYSTEM]
COMPONENT PARTS
Component Description
INFOID:0000000006226152
A/T Shift Selector (Detention Switch)INFOID:0000000006226153
Detention switch detects that A/T sh ift selector is in the P position, and then transmits the signal to BCM and
IPDM E/R.
BCM confirms the A/T shift selector position with the following 5 signals.
 P position signal from A/T shift selector (detention switch)
 P/N position signal from TCM
 P position signal from IPDM E/R (CAN)
 P/N position signal from IPDM E/R (CAN)
 P/N position signal from TCM (CAN)
IPDM E/R confirms the A/T shift select or position with the following 3 signals.
 P position signal from A/T shift selector (detention switch)
 P/N position signal from TCM
 P/N position signal from BCM (CAN)
BCMINFOID:0000000006226154
BCM controls INTELLIGENT KEY SYSTEM (ENGIN E START FUNCTION), INFINITI VEHICLE IMMOBI-
LIZER SYSTEM-NATS [IVIS (NATS)], and VEHICLE SECURITY SYSTEM.
BCM performs the ID verification between BCM and Intelligent Key when the Intelligent Key is carried into the
detection area of inside key antenna, and push-button ignition s witch is pressed. If the ID verification result is
OK, push-button ignition switch operation is available.
13. Front door swit ch (driver side)
Refer to DLK-11, "
DOOR LOCK
SYSTEM :
ComponentPartsLocation". 14. Remote keyless entry receiver
Refer to DLK-11, "
DOOR LOCK
SYSTEM :
ComponentPartsLocation". 15. Inside key antenna (luggage room)
Refer to DLK-11, "
DOOR LOCK
SYSTEM :
ComponentPartsLocation".
A. Behind push-button ignition switch
Component Reference
A/T shift selector (detention switch) SEC-8
BCMSEC-8
ECMSEC-9
IPDM E/RSEC-9
NATS antenna amp.SEC-9
TCMSEC-9
Combination meterSEC-9
Door switchSEC-9
Hood switchSEC-9
Inside key antennaSEC-9
Intelligent KeySEC-9
Push-button ignition switchSEC-10
Remote keyless entry receiverSEC-10
Security indicator lampSEC-10
Starter control relaySEC-10
Starter relaySEC-10
Steering lock relaySEC-10
Steering lock unitSEC-10
Stop lamp switchSEC-10
Transmission range switchSEC-10
Vehicle information display SEC-11
Revision: 2010 May2011 QX56

SEC-10
< SYSTEM DESCRIPTION >[WITH INTELLIGENT KEY SYSTEM]
COMPONENT PARTS
Push-button Ignition Switch
INFOID:0000000006226165
Push-button ignition switch detects that push-button is pressed, and then transmits the signal to BCM. BCM
changes the power supply position with the operation of push-button ignition switch. BCM maintains the power
supply position status while push-button is not operated.
Remote Keyless Entry ReceiverINFOID:0000000006226166
Remote keyless entry receiver receives each button oper ation signal and electronic key ID signal from Intelli-
gent Key, and then transmits the signal to BCM.
Security Indicator LampINFOID:0000000006226167
Security indicator lamp is located on combination meter.
Security indicator lamp blinks when power supply position is any position other than ON to warn that INFINITI
VEHICLE IMMOBILIZER SYSTEM-N ATS [IVIS (NATS)] is on board.
Starter Control RelayINFOID:0000000006226170
Engine starting system functions by controlling both starter relay and starter control relay.
Both relays are integrated in IPDM E/R. Starter relay is controlled by BCM, and starter control relay is con-
trolled by IPDM E/R on request from BCM.
IPDM E/R transmits starter relay and starter control relay status signal to BCM via CAN communication.
Starter RelayINFOID:0000000006226171
Engine starting system functions by controlling both starter relay and starter control relay.
Both relays are integrated in IPDM E/R. Starter relay is controlled by BCM, and starter control relay is con-
trolled by IPDM E/R on request from BCM.
IPDM E/R transmits starter relay and starter control relay status signal to BCM via CAN communication.
Steering Lock RelayINFOID:0000000006226172
Steering lock relay is integrated in IPDM E/R, and supplies power source to steering lock unit.
When IPDM E/R receives the steering lock relay ON request signal from BCM, IPDM E/R turns ON steering
lock relay and then transmits the steering lock relay condition signal to BCM.
Steering Lock UnitINFOID:0000000006226173
Steering lock unit performs steering lock/unlock operation on request from BCM, and power source is supplied
from steering lock relay integrated in IPDM E/R.
When push-button ignition switch is pressed while the In telligent Key is inside the vehicle, BCM performs the
ID verification with steering lock unit. Steering lock unit releases the steering lock based on the result of the ID
verification.
Steering lock unit has 2 switches (steering lock status switch and steering unlock status switch) inside. BCM
judges the steering lock/unlock condition by comparing these switch signals and steering lock unit status sig-
nal transmitted from IPDM E/R via CAN communication.
Stop Lamp SwitchINFOID:0000000006226174
Stop lamp switch detects that brake pedal is depressed, and then transmits the signal to BCM.
Transmission Range SwitchINFOID:0000000006226175
Transmission range switch is integrated in A/T asse mbly, and detects the A/T shift selector position.
TCM receives the transmission range switch signal and then transmits the P/N position signal to BCM and
IPDM E/R.
BCM confirms the A/T shift selector position with the following 5 signals.
 P position signal from A/T shift selector (detention switch)
 P/N position signal from TCM
 P position signal from IPDM E/R (CAN)
 P/N position signal from IPDM E/R (CAN)
 P/N position signal from TCM (CAN)
IPDM E/R confirms the A/T shift select or position with the following 3 signals.
Revision: 2010 May2011 QX56

SYSTEMSEC-15
< SYSTEM DESCRIPTION > [WITH INTELLIGENT KEY SYSTEM]
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INFINITI VEHICLE IMMOBILIZE R SYSTEM-NATS : System DiagramINFOID:0000000006226180
INFINITI VEHICLE IMMOBILIZER SYSTEM-NATS : System DescriptionINFOID:0000000006226181
SYSTEM DESCRIPTION
 The INFINITI VEHICLE IMMOBILIZER SYSTEM-NAT S [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 igni-
tion switch operation.
 Locate the security indicator lamp and apply the anti-t heft system equipment sticker that warns that the IVIS
(NATS) is on board the model.
 Security indicator lamp always blinks when the pow er 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. For the registration proce-
dures, refer to CONSULT-III O peration Manual NATS-IVIS/NVIS.
 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 according to SEC-48, "
Work
Flow".
 If ECM other than genuine part is installed, the engi ne cannot be started. For ECM replacement procedure,
refer to EC-143, "
Work Procedure".
JMKIA5734GB
Revision: 2010 May2011 QX56

SEC-16
< SYSTEM DESCRIPTION >[WITH INTELLIGENT KEY SYSTEM]
SYSTEM
PRECAUTIONS FOR KEY REGISTRATION
 The ID registration is a procedure that erases the cu
rrent IVIS (NATS) ID once, and then reregisters a new
ID. Therefore before starting the registration operation, collect all registered Intelligent Keys from the cus-
tomer.
 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 pow er 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 IG-
NITION SWITCH
1. When brake pedal is depressed while selector leve r 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) backsi de 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 trans-
mits the result to ECM.
4. When push-button ignition switch is pressed, BCM transmits steering unlock signal to steering lock unit
and IPDM E/R.
5. IPDM E/R turns steering lock relay ON and supplies power supply to the steering lock unit.
6. The steering lock is released.
7. BCM transmits the power supply stop signal to IPDM E/R when detecting that the steering lock is in the
unlock position.
8. IPDM E/R turns steering lock relay OFF and stops power supply to the steering lock unit.
9. BCM turns ACC relay ON and transmits 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 detects that the selector lever position is P or N.
12. 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.
13. IPDM E/R turns the starter control relay ON when receiving the starter request signal.
14. Power supply is supplied through the starter relay and the starter control relay to operate the starter motor.
15. When BCM receives feedback signal from ECM indica ting 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 unsuc-
cessful, 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 OPERA-
TION
The power supply position changing operation can be performed with the following operations.
NOTE:
 When an Intelligent Key is within the detection area of inside key antenna and when Intelligent Key backside
is contacted to push-button ignition switch, it is equivalent to the operations below.
 When starting the engine, the BCM monitors under the engine start conditions,
- Brake pedal operating condition
- Selector lever position
- Vehicle speed
Vehicle speed: less than 4 km/h (2.5 MPH)
Revision: 2010 May2011 QX56

SYSTEMSEC-17
< SYSTEM DESCRIPTION > [WITH INTELLIGENT KEY SYSTEM]
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Vehicle speed: 4 km/h (2.5 MPH) or more
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.
VEHICLE SECURITY SYSTEM
VEHICLE SECURITY SYSTEM : System DiagramINFOID:0000000006226184
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
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
JMKIA5735GB
Revision: 2010 May2011 QX56