2010 INFINITI QX56 4WD

DLN-116
< SYMPTOM DIAGNOSIS >[ATX14B]
ATP SWITCH
ATP SWITCH
DescriptionINFOID:0000000005148873
The ATP indicator is ON when the transfer case is not in neutral.
Diagnosis ProcedureINFOID:0000000005148874
Regarding Wiring Diagram information, refer to
DLN-89, "Wiring Diagram - ALL-MODE 4WD SYSTEM -".
1.CHECK ATP SWITCH SIGNAL
With CONSULT-III
1. Start engine.
2. Select DATA MONITOR mode for ALL MODE AWD/4WD with CONSULT-III.
3. Read out the value of ATP SWITCH.
Without CONSULT-III
1. Start engine.
2. Check voltage between transfer control unit harness connector
terminal and ground.
Are inspection results normal?
YES >> GO TO 5.
NO >> GO TO 2.
2.CHECK HARNESS BETWEEN TRANSFER CONTROL UNIT AND ATP SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect transfer control unit harness connector and the ATP switch harness connector.
3. Check continuity between transfer control unit harness connec- tor E143 terminal 40 and ATP switch harness connector F55 ter-
minal 8.
Also check harness for short to ground and short to power.
Are inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
Condition Display value
• Vehicle stopped
• Engine running
• A/T selector lever N
• Brake pedal de-
pressed 4WD shift switch
: 4H to 4LO or 4LO to 4H
(While actuator motor is operating.)
ON
Except the above OFF
Connector TerminalConditionVoltage
(Approx.)
E143 40 -
Ground • Vehicle stopped
• Engine running
• A/T selector lever
N
• Brake pedal de-
pressed 4WD shift switch: 4H
to 4LO or 4LO to 4H
(While actuator motor
is operating.)
0V
Except the above Battery
voltage
SDIA2755E
Continuity should exist.
SDIA2756E
Revision: April 20092010 QX56

ATP SWITCHDLN-117
< SYMPTOM DIAGNOSIS > [ATX14B]
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3.CHECK GROUND CIRCUIT
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.
3. Check continuity between ATP switch harness connector F55 terminal 9 and ground.
Also check harness for short to ground and short to power.
Are inspection results normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground or short to power in harness or connectors.
4.CHECK ATP SWITCH
1. Turn ignition switch OFF. (Stay for at least 5 seconds.)
2. Disconnect ATP switch harness connector.
3. Remove ATP switch. Refer to DLN-16, "
Component Parts Location".
4. Push and release ATP switch and check continuity between ATP switch terminals 8 and 9.
Are inspection results normal?
YES >> GO TO 5.
NO >> Replace ATP switch.
5.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are inspection results normal?
YES >> GO TO 6.
NO >> Check transfer control unit pin terminals for damage or loose connection with harness connector. If any items are damaged, repair or replace damaged parts.
6.CHECK ATP WARNING LAMP
1. Turn ignition switch ON. (Do not start engine.)
2. Move A/T selector lever to P position.
3. Set 4WD shift switch from 4H to 4LO or 4LO to 4H.
Does ATP warning lamp turn ON while switching?
YES >> Inspection End.
NO >> GO TO DLN-109, "
Diagnosis Procedure".
Continuity should exist.
SDIA2394E
Terminal
Condition Continuity
8 - 9 Push ATP switch
Yes
Release ATP switch No
SDIA2757E
Revision: April 20092010 QX56

DLN-118
< SYMPTOM DIAGNOSIS >[ATX14B]
4WD SYSTEM DOES NOT OPERATE
4WD SYSTEM DOES NOT OPERATE
DescriptionINFOID:0000000005148875
The vehicle can not be put into 4WD mode. (Possible hydraulic malfunction)
Diagnosis ProcedureINFOID:0000000005148876
1.CHECK SYSTEM FOR
4WD SHIFT SWITCH
Perform trouble diagnosis for 4WD shift switch system. Refer to DLN-32, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 2.
NO >> Repair or replace damaged parts.
2.CHECK SYSTEM FOR CLUT CH PRESSURE SWITCH
Perform trouble diagnosis for clutch pressure switch system. Refer to DLN-71, "
Diagnosis Procedure".
Are the inspection results normal?
YES >> GO TO 3.
NO >> Repair or replace damaged parts.
3.SYMPTOM CHECK
Check again.
Are the inspection results normal?
YES >> Inspection End.
NO >> GO TO 4.
4.CHECK TRANSFER CONTROL UNIT
Check transfer control unit input/output signal. Refer to DLN-81, "
Reference Value".
Are the inspection results normal?
YES >> GO TO 5.
NO >> Check transfer control unit pin terminals fo r damage or loose connection with harness connector.
If any items are damaged, repair or replace damaged parts.
5.CHECK TRANSFER INNER PARTS
1. Disassemble transfer assembly. Refer to DLN-142, "
Disassembly and Assembly".
2. Check transfer inner parts.
Are the inspection results normal?
YES >> Inspection End.
NO >> Repair or replace damaged parts.
Revision: April 20092010 QX56

PRECAUTIONSDLN-121
< PRECAUTION > [ATX14B]
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5. When the repair work is completed, return the ignition switch to the ″LOCK ″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of al l control units using CONSULT-III.
Precaution for Transfer Assembly and Transfer Control Unit ReplacementINFOID:0000000005148879
When replacing transfer assembly or transfer control uni t, check the 4WD shift indicator lamp as follows.
1. Turn ignition switch ON.
2. Check 4WD shift indicator lamp is turned ON for approximately 1 second.
• If OK, the position between transfer assembly and transfer control unit is correct.
• If NG, the position is different between transfer assembly and transfer control unit. Adjust the position between transfer assembly and transfer control unit. See METHOD FOR POSITION
ADJUSTMENT that follows.
METHOD FOR POSITION ADJUSTMENT
1. Start engine. Run the engine for at least 10 seconds.
2. Stop vehicle and move A/T selector lever to N position with brake pedal depressed. Stay in N for at least 2
seconds.
3. Turn 4WD shift switch to 2WD position. Stay in 2WD for at least 2 seconds.
4. Turn ignition switch OFF.
5. Start engine.
6. Erase self-diagnosis. Refer to DLN-18, "
CONSULT-III Function (ALL MODE AWD/4WD)".
7. Check 4WD shift indicator lamp. Refer to DLN-7, "
Preliminary Check".
If 4WD shift indicator lamp does not indicate 2WD, install new transfer control unit and retry the above
check.
PrecautionINFOID:0000000005148880
• Before connecting or disconnect ing the transfer control unit
harness connector, turn ignition switch “OFF” and disconnect
battery cables. Failure to do so may damage the transfer con-
trol unit. Battery voltage is ap plied to transfer control unit
even if ignition swit ch is turned “OFF”.
• When connecting or disconnecting pin connectors into or
from transfer control unit, take care not to damage pin termi-
nals (bend or break).
When connecting pin connectors make sure that there are not
any bends or breaks on transfer control unit pin terminals.
SEF289H
SEF291H
Revision: April 20092010 QX56

DLN-130
< ON-VEHICLE REPAIR >[ATX14B]
TRANSFER CONTROL UNIT
ON-VEHICLE REPAIR
TRANSFER CONTROL UNIT
Removal and InstallationINFOID:0000000005148887
REMOVAL
1. Set transfer state as 2WD when 4WD shift switch is at 2WD, or as AUTO when 4WD shift switch is at
AUTO.
CAUTION:
When removing transfer co ntrol unit, transfer state must be at 2WD or AUTO.
2. Turn the ignition switch OFF and disconnect negative battery terminal.
3. Remove the lower instrument panel RH. Refer to IP-17, "
Exploded View".
4. Disconnect the two transfer control unit connectors.
5. Remove the transfer control unit bolts.
6. Remove the transfer control unit.
INSTALLATION
Installation is in the reverse order of removal.
• When installing the transfer control unit, tighten bolts to the specified torque.
CAUTION:
Do not connect harness connector to transfer control unit when 4WD shift switch is at 4LO.
• After the installation, check perform self-diagnosis. Refer to DLN-6, "
Work Flow". If NG, adjust position
between transfer assembly and transfer control unit. Refer to DLN-121, "
Precaution for Transfer Assembly
and Transfer Control Unit Replacement".
BDIA0014E
Transfer control unit bolts : 3.4 N·m (0.35 kg-m, 30 in-lb)
Revision: April 20092010 QX56

DLN-136
< ON-VEHICLE REPAIR >[ATX14B]
TRANSFER CONTROL DEVICE
TRANSFER CONTROL DEVICE
Removal and InstallationINFOID:0000000005380646
REMOVAL
CAUTION:
Change vehicle state to AUTO, and then
remove and install transfer control device.
1. Remove front propeller shaft. Refer to DLN-186, "
Removal and Installation".
2. Disconnect the transfer control device connector.
3. Remove transfer control lever.
4. Disconnect vacuum line.
5. Remove transfer control device.
INSTALLATION
CAUTION:
Check 4WD shift indicator after installation. Refer to DLN-121, "
Precaution for Transfer Assembly and
Transfer Control Unit Replacement".
Installation is in the reverse order of removal.
1. Shift lever 2. Actuator
SDIA2654E
Revision: April 20092010 QX56

TRANSFER ASSEMBLYDLN-141
< REMOVAL AND INSTALLATION > [ATX14B]
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REMOVAL AND INSTALLATION
TRANSFER ASSEMBLY
Removal and InstallationINFOID:0000000005148894
REMOVAL
1. Set transfer state as 2WD when 4WD shift switch is at 2WD.
2. Remove the undercovers using power tool.
3. Drain the transfer fluid. Refer to TM-150, "
Changing the A/T Fluid (ATF)".
4. Remove the center exhaust tube and main muffler. Refer to EX-6, "
Removal and Installation".
5. Remove the front and rear propeller shafts. Refer to DLN-186, "
Removal and Installation" (front), DLN-
196, "Removal and Installation" (rear).
CAUTION:
Do not damage spline, sleeve yoke and rear oi l seal when removing rear propeller shaft.
NOTE:
Insert a plug into the rear oil seal after removing the rear propeller shaft.
6. Remove the A/T nuts from the A/T crossmember. Refer to TM-188, "
Removal and Installation (4WD)".
7. Position two suitable jacks under the A/T and transfer assembly.
8. Remove the crossmember. Refer to TM-188, "
Removal and Installation (4WD)".
WARNING:
Support A/T and transfer assembly using two suitable jacks while removing crossmember.
9. Disconnect the electrical connectors from the following: • ATP switch
• Neutral 4LO switch
• Wait detection switch
• Transfer motor
• Transfer control device
• Transfer terminal cord assembly
10. Disconnect each air breather hose from the following. Refer to DLN-137, "
Removal and Installation".
• Actuator
• Breather tube (transfer)
• Transfer motor
11. Remove the transfer control dev ice from the extension housing.
12. Remove the transfer to A/T and A/T to transfer bolts.
13. Remove the transfer assembly. WARNING:
Support transfer assembly with su itable jack while removing it.
CAUTION:
Do not damage rear oil seal (A/T).
INSTALLATION
Installation is in the reverse order of removal.
• Tighten the bolts to specification.
• Fill the transfer with new fluid and check for fluid leakage and fluid level. Refer to DLN-129, "
Replacement".
• Start the engine for one minute. Then stop the engine and recheck the transfer fluid. Refer to DLN-129, "
Inspection".
Transfer bolt torque : 36 N·m (3.7 kg-m, 27 ft-lb)
SMT872C
Revision: April 20092010 QX56

DLN-158
< DISASSEMBLY AND ASSEMBLY >[ATX14B]
TRANSFER ASSEMBLY
a. Remove all the bolts except for the two shown.
b. Remove the following from the control valve assembly:
• Clutch pressure solenoid valve
• Clutch pressure switch
• 2-4WD shift solenoid valve
• Line pressure switch
• Transfer fluid temperature sensor
c. Remove the O-rings from each solenoid valve, switch and termi- nal body.
d. Place the control valve with the lower body facing up. Remove the two bolts, and then remove the lower body and separator
plate from the upper body.
CAUTION:
Do not drop relief balls. Detach lower body carefully.
e. Make sure the reverse balls, relief balls, relief springs, accumu- lator pistons and valve springs are securely installed as shown,
and remove them.
f. Remove the retainer plates.
WDIA0198E
WDIA0199E
WDIA0200E
SDIA2126E
SDIA2127E
Revision: April 20092010 QX56