2011 INFINITI QX56 clutch

B2421 CLUTCH OPERATION TIMEDLK-97
< DTC/CIRCUIT DIAGNOSIS >
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B2421 CLUTCH OPERATION TIME
DTC LogicINFOID:0000000006225897
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Check “Self Diagnostic Result” mode of “AUTOMAT IC BACK DOOR CONTROL UNIT” using CONSULT-
III.
Is DTC detected?
YES >> Refer to DLK-97, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006225898
1.CHECK AUTOMATIC BACK DOOR CONTROL MODULE POWER SUPPLY AND GROUND CIRCUIT
1. Turn ignition switch OFF.
2. Check automatic back door control module power supply and ground circuit. Refer to DLK-116, "
AUTOMATIC BACK DOOR CONTROL UNIT : Diagnosis Procedure".
Is the inspection result normal?
YES >> Replace automatic back door control module. Refer to DLK-262, "Removal and Installation".
NO >> Repair or replace the malfunctioning parts.
DTC CONSULT-III display
description DTC detecting condition Possible cause
B2421 CLUTCH TIME OUT When the automatic back door control unit detects
the power distribution to the clutch for 2 minutes or
more  Automatic back door control mod-
ule
 Battery voltage (low voltage)
Revision: 2010 May2011 QX56

STRUCTURE AND OPERATIONDLN-13
< SYSTEM DESCRIPTION > [TRANSFER: ATX90A]
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STRUCTURE AND OPERATION
Sectional ViewINFOID:0000000006222222
Torque Split MechanismINFOID:0000000006222223
CONTROL DIAGRAM
1. Rear companion flange 2. Main shaft 3. Rear case
4. Ball ramp lever 5. Ball lamp lever 6. Piston
7. Clutch 8. Sprocket 9. Lock sleeve
10. Hi-Lo sleeve 11. Sun gear 12. Front case
13. Planetary carrier assembly 14. Internal gear 15. Shift fork
16. Transfer rotary position sensor 17. Front shaft flange 18. Drive chain
19. Actuator shaft 20. Cam 21. Transfer control actuator
JPDIE0277ZZ
Revision: 2010 May2011 QX56

DLN-14
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
STRUCTURE AND OPERATION
DESCRIPTION
 Ball ramp lever operates in the direction of main shaft axis according to rotation of actuator shaft and
presses piston. Pressure is applied to each clutch and torque is transmitted.
 Shift fork operates in the direction of main shaft axis according to rotation of actuator shaft and performs
engagement and disengagement to Hi-Lo sleeve and lock sleev e of main shaft. Mode is switched between
4H ⇔4L.
AUTO MODE
 The optimum torque distribution is electronically performed for front and rear wheels according to road con-
ditions.
 Stable start without wheel spin is possible on slippery road conditions, such as on a snowy road.
 When road condition does not require 4WD driving, the st atus becomes close to rear wheel drive, which
results in better fuel efficiency and prov ides FR-like steering characteristics.
 The vehicle cornering status is judged according to information from each sensor, and the optimum torque is
distributed to front wheels for prev enting tight-corner braking symptom.
NOTE:
When there is a difference of revolution speed between the front and rear wheel the shift occasionally changes
to direct 4-wheel driving conditions aut omatically. This is not a malfunction.
4H MODE
 Torque distribution for front and rear wheels is fixed and stable start is achieved while driving on an rough,
sandy or snowy road.
4L MODE
 Large traction force is obtained due to low gear. High running ability and escaping ability are achieved.
 Switching from 4H mode to 4L mode is not possible w hen the vehicle is not stopped and A/T shift selector is
not in the neutral position.
TORQUE DISTRIBUTION DIAGRAM
JPDIE0256GB
Revision: 2010 May2011 QX56

STRUCTURE AND OPERATIONDLN-15
< SYSTEM DESCRIPTION > [TRANSFER: ATX90A]
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TORQUE DISTRIBUTION FLOW
OPERATION PRINCIPLE
AUTO, 4H MODE
1. Main shaft 2. Clutch 3. Sprocket
4. Lock sleeve 5. Hi-Lo sleeve 6. Sun gear
7. Planetary carrier assembly 8. Front shaft flange 9. Drive chain
JPDIE0271GB
JPDIE0257GB
Revision: 2010 May2011 QX56

DLN-16
< SYSTEM DESCRIPTION >[TRANSFER: ATX90A]
STRUCTURE AND OPERATION
1. Transfer control unit supplies command current to transfer motor.
2. Transfer motor operates and actuator shaft rotates clockwise.
3. Shift fork operates according to rotation of actuator shaft. Sun gear and Hi-Lo sleeve are engaged.
4. Ball ramp lever operates in axial direction via cam fixed on actuator shaft according to traction torque of
transfer motor, presses piston, and thrusts multiple plate clutch.
5. Torque is transmitted to front wheels according to thrusting pressure of multiple plate clutch. NOTE:
Torque transmitted to the front wheel is determined according to the command current.
4L MODE
1. Main shaft 2. Ball lamp lever 3. Piston
4. Clutch 5. Hi-Lo sleeve 6. Sun gear
7. Shift fork 8. Actuator shaft 9. Transfer control actuator
JPDIE0278GB
Revision: 2010 May2011 QX56

DLN-102
< SYMPTOM DIAGNOSIS >[TRANSFER: ATX90A]
4WD WARNING LAMP BLINKS QUICKLY
4WD WARNING LAMP BLINKS QUICKLY
DescriptionINFOID:0000000006222318
While driving, 4WD warning lamp blinks 2 times in 1 second and it turns OFF after 1 minute.
 This symptom protects drivetrain parts when a heavy
load is applied to the electric controlled coupling and
multiple disc clutch temperature increases. Also, opt ional distribution of torque sometimes becomes rigid
before lamp blinks quickly. Both cases are not malfunction.
 When this symptom occurs, stop vehicle and allow it to idle for some times. Blinking will stop and system will be restored.
Revision: 2010 May2011 QX56

DIAGNOSIS SYSTEM (IPDM E/R)EXL-27
< SYSTEM DESCRIPTION > [XENON TYPE]
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DIAGNOSIS SYSTEM (IPDM E/R)
Diagnosis DescriptionINFOID:0000000006368066
AUTO ACTIVE TEST
Description
In auto active test, the IPDM E/R sends a drive signal to the following systems to check their operation.
 Oil pressure warning lamp
 Rear window defogger
 Front wiper (LO, HI)
 Parking lamp
 License plate lamp
 Tail lamp
 Side marker lamp
 Front fog lamp
 Headlamp (LO, HI)
 A/C compressor (magnet clutch)
Operation Procedure
CAUTION:
Never perform auto active test in the following conditions.
 Engine is running.
 CONSULT-III is connected.
1. Close the hood and lift the wiper arms from the windshield. (Prevent windshield damage due to wiper
operation)
NOTE:
When auto active test is performed with hood opened, sprinkle water on windshield beforehand.
2. Turn the ignition switch OFF.
3. Turn the ignition switch ON, and within 20 seconds, pr ess the driver door switch 10 times. Then turn the
ignition switch OFF.
CAUTION:
Close passenger door.
4. Turn the ignition switch ON within 10 seconds. Af ter that the horn sounds once and the auto active test
starts.
CAUTION:
Engine starts when ignition switch is turned ON while brake pedal is depressed.
5. The oil pressure warning lamp starts blinking when the auto active test starts.
6. After a series of the following operations is repeated 3 times, auto active test is completed.
NOTE:
 When auto active test has to be cancelled halfw ay through test, turn the ignition switch OFF.
 When auto active test is not activated, door swit ch may be the cause. Check door switch. Refer to DLK-117,
"ComponentFunctionCheck".
Inspection in Auto Active Test
When auto active test is actuated, the following operation sequence is repeated 3 times.
Operation
sequence Inspection location Operation
1 Oil pressure warning lamp Blinks continuously during operation of auto active test
2 Rear window defogger 10 seconds
3 Front wiper LO for 5 seconds → HI for 5 seconds
4 Parking lamp
 License plate lamp
 Tail lamp
 Side marker lamp
 Front fog lamp 10 seconds
Revision: 2010 May2011 QX56

EXL-28
< SYSTEM DESCRIPTION >[XENON TYPE]
DIAGNOSIS SYSTEM (IPDM E/R)
Concept of auto active test
 IPDM E/R starts the auto active test with the door
switch signals transmitted by BCM via CAN communica-
tion. Therefore, the CAN communication line between IPDM E/R and BCM is considered normal if the auto
active test starts successfully.
 The auto active test facilitates troubleshooting if any systems controlled by IPDM E/R cannot be operated.
Diagnosis chart in auto active test
5 Headlamp LO for 10 seconds →HI ON ⇔ OFF 5 times
6 A/C compressor (magnet clutch) ON ⇔ OFF 5 times
Operation
sequence Inspection location Operation
JMMIA0492GB
Symptom Inspection contents Possible cause
Rear window defogger does not operate Perform auto active test.
Does the rear window defog-
ger operate?YES BCM signal input circuit
NO  Rear window defogger
 Rear window defogger
ground circuit
 Harness or connector be- tween IPDM E/R and rear
window defogger
IPDM E/R
Any of the following components do not operate
 Parking lamp
 License plate lamp
Tail lamp
 Side marker lamp
Front fog lamp
 Headlamp (HI, LO)
 Front wiper (HI, LO) Perform auto active test.
Does the applicable system
operate?YES BCM signal input circuit
NO  Lamp or motor
 Lamp or motor ground cir-
cuit
 Harness or connector be- tween IPDM E/R and appli-
cable system
IPDM E/R
A/C compressor does not operate Perform auto active test.
Does the magnet clutch oper-
ate?YES
 A/C auto amp. signal input
circuit
 CAN communication signal
between A/C auto amp. and
ECM
 CAN communication signal
between ECM and IPDM E/
R
NO  Magnet clutch
 Harness or connector be-
tween IPDM E/R and mag-
net clutch
IPDM E/R
Revision: 2010 May2011 QX56