2011 INFINITI QX56 ABS

AIR COMPRESSOR/AIR TUBESCS-95
< REMOVAL AND INSTALLATION > [AIR LEVELIZER CONTROL SYSTEM]
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AIR COMPRESSOR/AIR TUBE
Exploded ViewINFOID:0000000006256101
Removal and InstallationINFOID:0000000006256102
REMOVAL
CAUTION:
Seal the removed part using vinyl tape for preventi ng dirt from getting on or entering the removed
part.
1. Lift up the vehicle.
2. Remove the cover.
3. Disconnect the air compressor harness connector.
1. Air tube A 2. Air tube B 3. Bracket
4. Air compressor 5. Clip 6. Cover
7. Insulator 8. Washer 9. Exhaust tube
10. Exhaust tube connector
A. To rear shock absorber (RH) B. To rear shock absorber (LH) C. To frame
: Vehicle front
Refer to GI-4, "
Components" for symbols not described on the above.
JSEIA0227GB
Revision: 2010 May2011 QX56

SCS-96
< REMOVAL AND INSTALLATION >[AIR LEVELIZER CONTROL SYSTEM]
AIR COMPRESSOR/AIR TUBE
4. Using a small spanner, remove the air tube A (1) and B (2) from
air compressor.
CAUTION:
Be careful since air flows swiftly from air tube.
5. Remove the exhaust tube (1) from exhaust tube connector (2).
6. Remove the exhaust tube connector only when it is damaged.
7. Remove the exhaust tube from air compressor.
8. Remove the air compressor from bracket.
9. Rmove the bracket from vehicle.
10. Remove the air tube A and B from rear shock absorbers RH and LH, according to the procedure in step 4.
11. Remove the air tube A and B from vehicle.
12. Perform inspection after removal. Rfer to SCS-97, "
Inspection".
INSTALLATION
Note the following, and install in the reverse order of the removal.
 When installing air tube (1) to air compressor or shock absorber,
insert as shown in the figure.
 Dry each component thoroughly before installing, to prevent mois-
ture from entering air compressor.
JSEIA0238ZZ
JSEIA0239ZZ
JSEIA0240GB
Revision: 2010 May2011 QX56

COMPONENT PARTSSEC-7
< SYSTEM DESCRIPTION > [WITH INTELLIGENT KEY SYSTEM]
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SYSTEM DESCRIPTION
COMPONENT PARTS
Component Parts LocationINFOID:0000000006226151
1. Inside key antenna (console) Refer to DLK-11, "
DOOR LOCK
SYSTEM :
ComponentPartsLocation". 2. A/T assembly
Refer to TM-10, "
A/T CONTROL
SYSTEM : Compon ent Parts Loca-
tion". 3. Push-button ignition switch
4. NATS antenna amp. 5. Inside key antenna (instrument cen- ter)
Refer to DLK-11, "
DOOR LOCK
SYSTEM :
ComponentPartsLocation". 6. IPDM E/R
Refer to PCS-4, "
Component Parts
Location".
7. ECM Refer to EC-16, "
Component Parts
Location"). 8. Horn 9. ABS actuator and electric unit (con-
trol unit)
Refer to BRC-10, "Component Parts
Location".
10. Stop lamp switch Refer to EC-16, "
Component Parts
Location". 11 . B C M
Refer to BCS-4, "
BODY CONTROL
SYSTEM : Compon ent Parts Loca-
tion". 12. Combination meter
Refer to MWI-6, "
METER SYSTEM :
Component Parts Location".
JMKIA5243ZZ
Revision: 2010 May2011 QX56

COMPONENT PARTSSEC-9
< SYSTEM DESCRIPTION > [WITH INTELLIGENT KEY SYSTEM]
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Then, when the power supply position is turned ON, BCM performs ID verification between BCM and ECM. If
the ID verification result is OK, ECM can start engine.
ECMINFOID:0000000006226155
ECM controls the engine.
When power supply position is turned ON, BCM starts communication with ECM and performs the ID verifica-
tion between BCM and ECM.
If the verification result is OK, the engine can start. If the verification result is NG, the engine can not start.
IPDM E/RINFOID:0000000006226156
IPDM E/R has steering lock relay, starter relay and starte r control relay inside. Steering lock relay is used for
the steering lock/unlock function. Starter relay and star ter control relay are used for the engine starting func-
tion. IPDM E/R controls these relays while communicating with BCM.
NATS Antenna Amp.INFOID:0000000006226157
The ID verification is performed between BCM and transponder in Intelligent Key via NATS antenna amp.
when Intelligent Key backside is contacted to push-button i gnition switch in case that Intelligent Key battery is
discharged. If the ID verification result is OK, the release of steering lock and the operation of starting engine
is available.
TCMINFOID:0000000006226158
TCM transmits the shift position signal (P/N position) to BCM and IPDM E/R. And further, TCM transmits the
shift position signal (P/N position) to BCM via CAN communication.
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 sele ctor 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)
Combination MeterINFOID:0000000006226159
Combination meter transmits the vehicle speed signal to BCM via CAN communication.
BCM also receives the vehicle speed signal from ABS ac tuator and electric unit (control unit) via CAN commu-
nication. BCM compares both signals to detect the vehicle speed.
Door SwitchINFOID:0000000006226160
Door switch detects door open/close condition and then transmits ON/OFF signal to BCM.
Hood SwitchINFOID:0000000006226161
Hood switch detects that hood is open, and then transmits the signal to IPDM E/R. IPDM E/R transmits hood
switch signal to BCM via CAN communication.
Inside Key AntennaINFOID:0000000006226162
Inside key antenna detects whether Intelligent Key is inside the vehicle, and transmits the signal to BCM.
Three inside key antennas are installed in t he instrument center, console and luggage room.
Intelligent KeyINFOID:0000000006226163
Each Intelligent key has an individual electronic ID , and transmits the ID signal by request from BCM.
Carrying the Intelligent Key whose ID is registered in BCM, the driver can performs door lock/unlock operation
and push-button ignition switch operation.
Revision: 2010 May2011 QX56

SEC-24
< SYSTEM DESCRIPTION >[WITH INTELLIGENT KEY SYSTEM]
DIAGNOSIS SYSTEM (BCM)
SELF-DIAG RESULT
Refer to
BCS-57, "DTCIndex".
DATA MONITOR
PW DOWN SET Unlock button pressing time on Intelligent Key button can be selected from the following with
this mode
 MODE 1: 3 sec
 MODE 2: Non-operation
 MODE 3: 5 sec
WELCOME LIGHT SELECT Welcome light function mode can be selected from the following with this mode
 Puddle/Outside Handle
 Room lamp
 Head & Tail Lamps (this item is displayed, but cannot be used)
 Heart Beat
WELCOME LIGHT OP SET Welcome light function mode can be changed to operation with this mode
 On: Operate
 Off: Non-operation
Monitor item Description
Monitor Item Condition
REQ SW -DR Indicates [On/Off] condition of door request switch (driver side)
REQ SW -AS Indicates [On/Off] condition of door request switch (passenger side)
REQ SW -BD/TR Indicates [On/Off] condition of back door request switch
PUSH SW Indicates [On/Off] condition of push-button ignition switch
CLUTCH SW NOTE:
This item is displayed, but cannot be monitored
BRAKE SW 1 Indicates [On/Off]* condition of stop lamp switch power supply
BRAKE SW 2 Indicates [On/Off] condition of stop lamp switch
DETE/CANCL SW Indicates [On/Off] condition of P position
SFT PN/N SW Indicates [On/Off] condition of P or N position
S/L -LOCK Indicates [On/Off] condition of steering lock unit (LOCK)
S/L -UNLOCK Indicates [On/Off] condition of steering lock unit (UNLOCK)
S/L RELAY -F/B Indicates [On/Off] condition of steering lock relay
UNLK SEN -DR Indicates [On/Off] condition of driver door UNLOCK status
PUSH SW -IPDM Indicates [On/Off] condition of push-button ignition switch
IGN RLY1 -F/B Indicates [On/Off] condition of ignition relay 1
DETE SW -IPDM Indicates [On/Off] condition of P position
SFT PN -IPDM Indicates [On/Off] condition of P or N position
SFT P -MET Indicates [On/Off] condition of P position
SFT N -MET Indicates [On/Off] condition of N position
ENGINE STATE Indicates [Stop/Stall/Crank/Run] condition of engine states
S/L LOCK-IPDM Indicates [On/Off] condition of steering lock unit (LOCK)
S/L UNLK-IPDM Indicates [On/Off] condition of steering lock unit (UNLOCK)
S/L RELAY-REQ Indicates [On/Off] condition of steering lock relay
VEH SPEED 1 Display the vehicle speed signal received from combination meter by numerical value [Km/h]
VEH SPEED 2 Display the vehi cle speed signal received from ABS or VDC or TCM by numerical value [Km/h]
DOOR STAT-DR Indicates [LOCK/READY/UNLK] condition of unlock sensor
DOOR STAT-AS Indicates [LOCK/READY/UNLK] condition of passenger side door status
ID OK FLAG Indicates [Set/Reset] condition of key ID
PRMT ENG STRT Indicates [Set/Reset] condition of engine start possibility
Revision: 2010 May2011 QX56

SEC-78
< DTC/CIRCUIT DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
B2557 VEHICLE SPEED
B2557 VEHICLE SPEED
DTC LogicINFOID:0000000006226228
DTC DETECTION LOGIC
NOTE:
 If DTC B2557 is displayed with DTC U1000, first perform the trouble diagnosis for DTC U1000. Refer to
BCS-70, "
DTC Logic".
 If DTC B2557 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. Start engine and wait 10 seconds or more.
2. Drive the vehicle at a vehicle speed of 10 km/h (6.2 MPH) or more for 10 seconds or more.
3. Check DTC in “Self Diagnostic Result” mode of “BCM” using CONSULT-III.
Is DTC detected?
YES >> Go to SEC-78, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006226229
1.CHECK DTC OF “ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)”
Check DTC in “Self Diagnostic Result ” mode of “ABS” using CONSULT-III.
Is DTC detected?
YES >> Perform the trouble diagnosis relat ed to the detected DTC. Refer to BRC-51, "DTC Index".
NO >> GO TO 2.
2.CHECK DTC OF “COMBINATION METER”
Check DTC in “Self Diagnostic Result” m ode of “METER/M&A” using CONSULT-III.
Is DTC detected?
YES >> Perform the trouble diagnosis relat ed to the detected DTC. Refer to MWI-43, "DTC Index".
NO >> GO TO 3.
3.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
DTC No. Trouble diagnosis name DTC detecting condition Possible causes
B2557 VEHICLE SPEED BCM detects one of the following conditions for 10
seconds continuously.
 Vehicle speed signal from combination meter is 10
km/h (6.2 MPH) or more, and vehicle speed signal
from ABS actuator and electric unit (control unit) is
4 km/h (2.5 MPH) or less.
 Vehicle speed signal from combination meter is 4 km/h (2.5 MPH) or less, and vehicle speed signal
from ABS actuator and electric unit (control unit) is
10 km/h (6.2 MPH) or more.  Harness or connectors
(The CAN communication line is
open or shorted.)
 Combination meter
 ABS actuator and electric unit
(control unit)
Revision: 2010 May2011 QX56

TM-10
< SYSTEM DESCRIPTION >[7AT: RE7R01B]
COMPONENT PARTS
SYSTEM DESCRIPTION
COMPONENT PARTS
A/T CONTROL SYSTEM
A/T CONTROL SYSTEM : Co
mponent Parts LocationINFOID:0000000006226738
1. Yaw rate/side/decel G sensor
Refer to BRC-10, "
Component Parts
Location". 2.
Tow mode switch
*13. IPDM E/R
Refer to PCS-4, "
Component Parts
Location".
4. ECM Refer to EC-16, "
Component Parts
Location". 5. ABS actuator and electric unit (con-
trol unit)
Refer to BRC-10, "Component Parts
Location". 6. Accelerator pedal position sensor
Refer to EC-16, "
Component Parts
Location".
7. Stop lamp switch Refer to BRC-10, "
Component Parts
Location". 8. BCM
Refer to BCS-4, "
BODY CONTROL
SYSTEM : Component Parts Loca-
tion". 9. Combination meter
Refer to MWI-6, "
METER SYSTEM :
Component Parts Location".
10. Shift position indicator (In the information display in the
combination meter) 11. A/T CHECK indicator lamp
(On the combination meter) 12. Tow mode indicator lamp
13. Selector lever position indicator 14. Manual mode switch 15. A/T assembly connector
16. Output speed sensor
*217.Control valve & TCM*3
A. Center console B. A/T shift selector assembly C. A/T assembly
*1 : Tow mode switch is integrated in to SNOW MODE/TOW MODE/VDC OFF switch assembly (2WD models) or 4WD switch
assembly (4WD models).
*2 : Output speed sensor is installed in A/T assembly.
*3 : Control valve & TCM is installed in A/T assembly.
JSDIA1773GB
Revision: 2010 May2011 QX56

COMPONENT PARTSTM-11
< SYSTEM DESCRIPTION > [7AT: RE7R01B]
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NOTE:
The following components are included in the control valve & TCM (17).
TCM
 Input speed sensor 1, 2
 A/T fluid temperature sensor
 Transmission range switch
 Direct clutch solenoid valve
 High and low reverse clutch solenoid valve
 Input clutch solenoid valve
 Front brake solenoid valve
 Low brake solenoid valve
 Anti-interlock solenoid valve
 2346 brake solenoid valve
 Line pressure solenoid valve
 Torque converter clutch solenoid valve
A/T CONTROL SYSTEM : Component DescriptionINFOID:0000000006226739
Name Function
TCM TM-12, "
A/T CONTROL SYSTEM : TCM"
Transmission range switchTM-12, "A/T CONTROL SYSTEM : Transmission Range Switch"
Output speed sensor TM-12, "A/T CONTROL SYSTEM : Output Speed Sensor"
Input speed sensor 1
TM-12, "A/T CONTROL SYSTEM : Input Speed Sensor"Input speed sensor 2
A/T fluid temperature sensorTM-12, "
A/T CONTROL SYSTEM : A/T Fluid Temperature Sensor"
Input clutch solenoid valve TM-12, "A/T CONTROL SYSTEM : Input Clutch Solenoid Valve"
Front brake solenoid valve TM-12, "A/T CONTROL SYSTEM : Front Brake Solenoid Valve"
Direct clutch solenoid valveTM-12, "A/T CONTROL SYSTEM : Direct Clutch Solenoid Valve"
High and low reverse clutch solenoid valveTM-13, "A/T CONTROL SYSTEM : High and Low Reverse Clutch Solenoid Valve"
Low brake solenoid valve TM-13, "A/T CONTROL SYSTEM : Low Brake Solenoid Valve"
Anti-interlock solenoid valve TM-13, "A/T CONTROL SYSTEM : Anti-interlock Solenoid Valve"
2346 brake solenoid valve TM-13, "A/T CONTROL SYSTEM : 2346 Brake Solenoid Valve"
Torque converter clutch solenoid valveTM-13, "A/T CONTROL SYSTEM : Torque Converter Clutch Solenoid Valve"
Line pressure solenoid valve TM-13, "A/T CONTROL SYSTEM : Line Pressure Solenoid Valve"
Accelerator pedal position sensor TM-13, "A/T CONTROL SYSTEM : Accelerator Pedal Position Sensor"
Manual mode switch TM-13, "A/T CONTROL SYSTEM : Manual Mode Switch"
Tow mode switch TM-14, "A/T CONTROL SYSTEM : Tow Mode Switch"
A/T CHECK indicator lampTM-14, "A/T CONTROL SYSTEM : A/T CHECK Indicator Lamp"
Tow mode indicator lamp* TM-14, "A/T CONTROL SYSTEM : Tow Mode Indicator Lamp"
Selector lever position indicator TM-14, "A/T CONTROL SYSTEM : Selector Lever Position Indicator"
Stop lamp switch BRC-15, "Stop Lamp Switch"
Yaw rate/side G sensorBRC-15, "Yaw Rate/Side/Decel G sensor"
Starter relay STR-6, "System Description"
ECMEC-35, "ENGINE CONTROL SYSTEM : System Description"
BCM BCS-6, "BODY CONTROL SYSTEM : System Description"
Combination meter MWI-9, "METER SYSTEM : System Description"
ABS actuator and electric unit (control unit) BRC-16, "System Description"
Revision: 2010 May2011 QX56