2011 INFINITI QX56 power steering

B26EF STEERING LOCK RELAYSEC-107
< DTC/CIRCUIT DIAGNOSIS > [WITH INTELLIGENT KEY SYSTEM]
C
D
E
F
G H
I
J
L
M A
B
SEC
N
O P
B26EF STEERING LOCK RELAY
DTC LogicINFOID:0000000006226262
DTC DETECTION LOGIC
NOTE:
 If DTC B26EF is displayed with DTC U1000, firs t perform the trouble diagnosis for DTC U1000. Refer to
BCS-70, "
DTC Logic".
 If DTC B26EF is displayed with DTC U1010, firs t perform the trouble diagnosis for DTC U1010. Refer to
BCS-71, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
1. Shift selector lever to the P position.
2. Turn ignition switch ON.
3. Turn ignition switch OFF.
4. Press driver side door switch and wait 2 seconds or more.
5. Check DTC in “Self Diagnostic Result” mode of “BCM” using CONSULT-III.
Is DTC detected?
YES >> Go to SEC-107, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006226263
1.CHECK DTC OF IPDM E/R
Check DTC in “Self Diagnostic Result” mode of “IPDM E/R” using CONSULT-III.
Is DTC detected?
YES >> Perform the diagnosis procedure rela ted to the detected DTC. Refer to PCS-22, "DTCIndex".
NO >> GO TO 2.
2.CHECK STEERING LOCK UNIT POWER SUPPLY
Check voltage between steering lock unit harness connector and ground.
NOTE:
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
B26EF STRG LCK RELAY OFF BCM requests IPDM E/R to turn steering lock
relay ON, but BCM cannot receive steering
lock relay ON state signal from IPDM E/R
(CAN) within 2 seconds.  Harness or connectors
(CAN communication line is open
or shorted.)
 Harness or connector (Steering lock unit circuit is open or
shorted.)
 Steering lock unit
 IPDM E/R
(+)
(–) Condition Voltage (V)
(Approx.)
Steering lock unit
Connector Terminal
M12 1 Ground Ignition switch
OFF
A few seconds after
opening the driver door
Battery voltage
Ignition switch
LOCK Press the push-button
ignition switch
Battery voltage
Ignition switch ACC or ON 0
Revision: 2010 May2011 QX56

SEC-108
< DTC/CIRCUIT DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
B26EF STEERING LOCK RELAY
Is the inspection normal?
YES >> GO TO 3.
NO >> GO TO 4.
3.REPLACE STEERING LOCK UNIT
1. Replace steering lock unit.
2. Perform the service procedure for steering lock unit replacement. Refer to CONSULT-III Operation Man-
ual NATS-IVIS/NVIS.
>> INSPECTION END
4.CHECK STEERING LOCK RELAY CIRCUIT
1. Disconnect IPDM E/R connector and steering lock unit connector.
2. Check continuity between IPDM E/R harness connector and steering lock unit harness connector.
3. Check continuity between IP DM E/R harness connector and ground.
Is the inspection result normal?
YES >> Replace IPDM E/R. Refer to PCS-32, "Removal and Installation".
NO >> Repair or replace harness.
To lock the steering 1. Set the selector lever in the P position.
2. Turn the power supply position to the OFF position.
3. Press any door switch.
To unlock the steering 1. Set the selector lever in the P position.
2. Press the push-button ignition switch with brake pedal not depressed.
IPDM E/R Steering lock unit
Continuity
Connector Terminal Connector Terminal
E14 46 M12 1 Existed
IPDM E/R GroundContinuity
Connector Terminal
E14 46 Not existed
Revision: 2010 May2011 QX56

B26F0 STEERING LOCK RELAYSEC-109
< DTC/CIRCUIT DIAGNOSIS > [WITH INTELLIGENT KEY SYSTEM]
C
D
E
F
G H
I
J
L
M A
B
SEC
N
O P
B26F0 STEERING LOCK RELAY
DTC LogicINFOID:0000000006226264
DTC DETECTION LOGIC
NOTE:
 If DTC B26F0 is displayed with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to
BCS-70, "
DTC Logic".
 If DTC B26F0 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer to
BCS-71, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
1. Shift selector lever to the P position.
2. Turn ignition switch ON.
3. Turn ignition switch OFF.
4. Press driver side door switch and wait 2 seconds or more.
5. Check DTC in “Self Diagnostic Result” mode of “BCM” using CONSULT-III.
Is DTC detected?
YES >> Go to SEC-109, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006226265
1.CHECK DTC OF IPDM E/R
Check DTC in “Self Diagnostic Result” mode of “IPDM E/R” using CONSULT-III.
Is DTC detected?
YES >> Perform the diagnosis procedure rela ted to the detected DTC. Refer to PCS-22, "DTCIndex".
NO >> GO TO 2.
2.CHECK STEERING LOCK UNIT POWER SUPPLY
Check voltage between steering lock unit harness connector and ground.
NOTE:
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
B26F0 STRG LCK RELAY ON BCM requests IPDM E/R to turn steering lock
relay OFF, but BCM cannot receive steering
lock relay OFF state signal from IPDM E/R
(CAN) within 2 seconds.  Harness or connectors
(CAN communication line is open
or shorted.)
 Harness or connector (Steering lock unit circuit is open or
shorted.)
 Steering lock unit
IPDM E/R
(+)
(–) Condition Voltage (V)
(Approx.)
Steering lock unit
Connector Terminal
M12 1 Ground Ignition switch
OFF
A few seconds after
opening the driver door
Battery voltage
Ignition switch
LOCK Press the push-button
ignition switch
Battery voltage
Ignition switch ACC or ON 0
Revision: 2010 May2011 QX56

SEC-110
< DTC/CIRCUIT DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
B26F0 STEERING LOCK RELAY
Is the inspection normal?
YES >> GO TO 3.
NO >> GO TO 4.
3.REPLACE STEERING LOCK UNIT
1. Replace steering lock unit.
2. Perform the service procedure for steering lock unit replacement. Refer to CONSULT-III Operation Man-
ual NATS-IVIS/NVIS.
>> INSPECTION END
4.CHECK STEERING LOCK RELAY CIRCUIT
1. Disconnect IPDM E/R connector and steering lock unit connector.
2. Check continuity between IPDM E/R harness connector and steering lock unit harness connector.
3. Check continuity between IP DM E/R harness connector and ground.
Is the inspection result normal?
YES >> Replace IPDM E/R. Refer to PCS-32, "Removal and Installation".
NO >> Repair or replace harness.
To lock the steering 1. Set the selector lever in the P position.
2. Turn the power supply position to the OFF position.
3. Press any door switch.
To unlock the steering 1. Set the selector lever in the P position.
2. Press the push-button ignition switch with brake pedal not depressed.
IPDM E/R Steering lock unit
Continuity
Connector Terminal Connector Terminal
E14 46 M12 1 Existed
IPDM E/R GroundContinuity
Connector Terminal
E14 46 Not existed
Revision: 2010 May2011 QX56

B26F5 STEERING LOCK STATUS SWITCHSEC-113
< DTC/CIRCUIT DIAGNOSIS > [WITH INTELLIGENT KEY SYSTEM]
C
D
E
F
G H
I
J
L
M A
B
SEC
N
O P
B26F5 STEERING LOCK STATUS SWITCH
DTC LogicINFOID:0000000006226270
DTC DETECTION LOGIC
NOTE:
 If DTC B26F5 is displayed with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to
BCS-70, "
DTC Logic".
 If DTC B26F5 is displayed with DTC U1010, first perform the trouble diagnosis for DTC U1010. Refer to
BCS-71, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
1. Shift selector lever to the P position.
2. Turn ignition switch ON.
3. Turn ignition switch OFF.
4. Press driver side door switch.
5. Check DTC in “Self Diagnostic Result” mode of “BCM” using CONSULT-III.
Is DTC detected?
YES >> Go to SEC-113, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006226271
1.CHECK IPDM E/R INPUT SIGNAL
1. Turn ignition switch OFF.
2. Check voltage between IPDM E/R harness connector and ground.
NOTE:
Is the inspection result normal?
YES >> GO TO 4.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause B26F5 STRG LCK STS SW When BCM performs steering lock request
to IPDM E/R, steering lock state signal
from IPDM E/R is already lock state.  Harness or connectors
(CAN communication line is open or
shorted.)
 Harness or connectors (Steering lock unit circuit is open or
shorted.)
 Steering lock unit
IPDM E/R
BCM
(+)
(–) Condition Voltage (V)
(Approx.)
IPDM E/R
Connector Terminal
E17 63
Ground Steering lock unit Lock 12
Unlock 0
65 Lock 0
Unlock 12
To lock the steering 1. Set the selector lever in the P position.
2. Turn the power supply position to the OFF position.
3. Press any door switch.
To unlock the steering 1. Set the selector lever in the P position.
2. Press the push-button ignition switch with brake pedal not depressed.
Revision: 2010 May2011 QX56

SEC-114
< DTC/CIRCUIT DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
B26F5 STEERING LOCK STATUS SWITCH
NO >> GO TO 2.
2.CHECK IPDM E/R INPUT SIGNAL CIRCUIT
1. Disconnect IPDM E/R connector and steering lock unit connector.
2. Check continuity between IPDM E/R harness connector and steering lock unit harness connector.
3. Check continuity between IP DM E/R harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace harness.
3.REPLACE STEERING LOCK UNIT
1. Replace steering lock unit.
2. Perform the service procedure for steering lock unit replacement. Refer to CONSULT-III Operation Man-
ual NATS-IVIS/NVIS.
>> INSPECTION END
4.CHECK BCM INPUT SIGNAL
1. Turn ignition switch OFF.
2. Check voltage between BCM harness connector and ground.
NOTE:
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 6.
5.REPLACE BCM
1. Replace BCM. Refer to BCS-81, "
Removal and Installation".
2. Perform initialization of BCM and registration of all Intelligent Keys using CONSULT-III.
For initialization and registration procedures, refer to CONSULT-III Operation Manual NATS-IVIS/NVIS.
IPDM E/R Steering lock unit
Continuity
Connector Terminal Connector Terminal
E17 63
M12 8
Existed
65 3
IPDM E/R GroundContinuity
Connector Terminal
E17 63
Not existed
65
(+)
(–) Condition Voltage (V)
(Approx.)
BCM
Connector Terminal
M71 107
Ground Steering lock unit Lock 0
Unlock 12
108 Lock 12
Unlock 0
To lock the steering 1. Set the selector lever in the P position.
2. Turn the power supply position to the OFF position.
3. Press any door switch.
To unlock the steering 1. Set the selector lever in the P position.
2. Press the push-button ignition switch with brake pedal not depressed.
Revision: 2010 May2011 QX56

SEC-128
< DTC/CIRCUIT DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
B2109 STEERING LOCK RELAY
B2109 STEERING LOCK RELAY
DTC LogicINFOID:0000000006226288
DTC DETECTION LOGIC
NOTE:
 If DTC B2109 is displayed with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to
PCS-32, "
Removal and Installation".
 If DTC B2109 is displayed with other DTC, firs t perform the trouble diagnosis for the other DTC.
 When IPDM E/R power supply voltage is low (Approx . 7 - 8 V for about 1 second), the DTC B2109 may be
detected.
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
1. Press push-button ignition switch under the foll owing conditions and wait 1 second or more.
- Selector lever: In the P position
- Brake pedal: Not depressed
2. Check DTC in “Self Diagnostic Result” mode of “IPDM E/R” using CONSULT-III.
Is DTC detected?
YES >> Go to SEC-128, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006226289
1.CHECK POWER SUPPLY CIRCUIT
Check IPDM E/R power supply circuit. Refer to PCS-31, "
Diagnosis Procedure".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace the malfunctioning part.
2.CHECK FUSE
1. Turn ignition switch OFF.
2. Check 10 A fuse (No. 44, located in IPDM E/R).
Is the inspection result normal?
YES >> Replace IPDM E/R. Refer to PCS-32, "Removal and Installation".
NO >> Replace the blown fuse after repairing the cause of ffected circuit if a fuse is blown.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
B2109 STRG LCK RELAY OFF IPDM E/R detects that steering lock relay is
stuck in the OFF position for approximately 1
second even if IPDM E/R receives steering
lock relay ON/OFF signal from BCM.  Harness or connector
(CAN communication line is open or
shorted.)
 Harness or connector (Power supply circui t for steering lock
relay is open or shorted.)
IPDM E/R
 Battery
Revision: 2010 May2011 QX56

SR-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006113043
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the “SRS AIR BAG” and “SEAT BELT” of this
Service Manual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision that would result in air bag inflation, all maintenance must be performed by
an authorized NISS AN/INFINITI dealer.
 Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the “SRS AIR BAG”.
 Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
 When working near the Air Bag Diagnosis Sensor Unit or other Air Bag System sensors with the ignition ON or engine running, DO NOT use air or electric power tools or strike near the sensor(s)
with a hammer. Heavy vibration could activate the sensor(s) and deploy the air bag(s), possibly
causing serious injury.
 When using air or electric power tools or hammers , always switch the ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation after Battery Disconnect
INFOID:0000000006113044
NOTE:
 Before removing and installing any control units, first tu rn the push-button ignition switch to the LOCK posi-
tion, then disconnect bot h battery cables.
 After finishing work, confirm that all control unit connectors are connected properly, then re-connect both
battery cables.
 Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If a DTC is detected, perform trouble diagnos is according to self-diagnosis results.
For vehicle with steering lock unit, if the battery is disconnected or discharged, the steering wheel will lock and
cannot be turned.
If turning the steering wheel is required with the bat tery disconnected or discharged, follow the operation pro-
cedure below before starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Turn the push-button ignition switch to ACC position. (At this time, the steering lock will be released.)
3. Disconnect both battery cables. The steering lock wi ll remain released with both battery cables discon-
nected and the steering wheel can be turned.
4. Perform the necessary repair operation.
Revision: 2010 May2011 QX56