2008 INFINITI QX56 transmission

CCS
DTC 97 AT CIRCUITCCS-39
< COMPONENT DIAGNOSIS >
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DTC 97 AT CIRCUIT
DTC 97 AT CIRCUITINFOID:0000000001744714
1.CHECK A/T CIRCUIT
With TCM diagnosis, check that shift operates normally. Refer to TM-20, "
TCM Function".
Is the transmission operating normally?
YES >> Replace ICC unit. Refer to CCS-70, "ICC Unit".
NO >> • Perform TCM diagnosis. • Erase DTC and perform self-diagnosis of ICC system again.
Revision: March 2010 2008 QX56

CCS-40
< COMPONENT DIAGNOSIS >
DTC 98 GEAR POSITION
DTC 98 GEAR POSITION
DTC 98 GEAR POSITIONINFOID:0000000001744715
1.DIAGNOSTIC CHECK
Perform ICC self diagnosis.
Does "DTC 43 VDC/TCS/ABS CIRC" or "DTC 41 VHCL SP EED SE CIRC" indicated in self-diagnosis display
item?
YES >> Repair or replace as necessary. Erase DTC and perform self-diagnosis of ICC system again.
NO >> GO TO 2
2.CHECK VEHICLE SPEED SIGNAL
With data monitor, check that “VHCL SPEED SE” is normal.
Does the "VHCL SPEED SE" monitor item display normally?
YES >> GO TO 3
NO >> Replace ICC unit. Refer to CCS-70, "
ICC Unit". Erase DTC and perform self-diagnosis of ICC sys-
tem again.
3.CHECK GEAR SHIFT POSITION
Check that gear positions are correct in A/T.
Does the transmission operate normally?
YES >> GO TO 5
NO >> GO TO 4
4.CHECK TCM GEAR POSITION SIGNAL
With TCM data monitor, check that gear positions are correct.
Does the data monitor indicate proper gear positions?
YES >> Replace ICC unit. Refer to CCS-70, "ICC Unit".
NO >> • Perform TCM diagnosis.
• Erase DTC and perform self-d iagnosis of ICC system again.
5.CHECK TCM TURBINE ROTATION
With TCM diagnosis, check that turbine rpm is normal. Refer to TM-46, "
Description".
Does the TCM check OK?
YES >> Replace ICC unit. Refer to CCS-70, "ICC Unit".
NO >> • Perform TCM diagnosis.
• Erase DTC and perform self-d iagnosis of ICC system again. CCS-17, "
Diagnosis Description"
Revision: March 2010 2008 QX56

CCS
ICC UNITCCS-55
< ECU DIAGNOSIS >
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Diagnostic Trouble Code (DTC) ChartINFOID:0000000001757410
× :Applicable
DTC
No. CONSULT-III screen terms ICC sys-
tem
warning lamp Fail-safe
Malfunctions detected where... Refer-
ence
page
Veh ic le-
to-vehi-cle dis-
tance
control mode Conven-
tional
(fixed
speed) cruise
control mode Brake as-
sist (with
preview
function)
11 CONTROL UNIT ×××× • ICC unit internal malfunctionCCS-22
12 VDC CONTROL UNIT ×××× • VDC malfunction
• Brake booster signal harness is
open or shorted CCS-23
20 CAN COMM CIRCUIT
×××× • ICC unit detected CAN communi-
cation malfunction CCS-24
31 POWER SUPPLY CIR1
×××× • ICC unit power supply voltage is
excessively low (less than 8V) CCS-25
34 POWER SUPPLY CIR2
×××× • ICC unit power supply voltage is
excessively high. CCS-25
41 VHCL SPEED SE CIRC
×××× • Wheel sensor malfunction
• ABS actuator and electric unit
(control unit) malfunction
• A/T vehicle speed sensor mal-
function
•TCM malfunction CCS-26
43 VDC/TCS/ABS CIRC
×××× • VDC/TCS/ABS system malfunc-
tion CCS-27
45 BRAKE SW/ STOP L SW
×××× • ICC brake switch or stop lamp
switch harness is open or shorted
• ICC brake switch or stop lamp switch is stuck to OFF
• ICC brake switch or stop lamp switch is stuck to ON CCS-28
46 OPERATION SW CIRC
××× • ICC steering switch harness or
spiral cable is open or shorted
• ICC steering switch malfunction CCS-30
74 LASER BEAM OFF CNTR
××ו Laser beam of ICC sensor is off
the aiming point CCS-31
90 STOP LAMP RLY FIX
××ו Normally open terminal of stop
lamp relay is stuck CCS-32
92 ECM CIRCUIT
×××× •ECM malfunction
• Accelerator pedal position sensor
malfunction
• ICC unit malfunction CCS-37
96 NP RANGE
××× • Transmission range switch har-
ness is open or shorted
• Transmission range switch mal- function
•TCM malfunction CCS-38
97 AT CIRCUIT
××× •TCM malfunctionCCS-39
98 GEAR POSITION ××× •TCM malfunction
• A/T input speed sensor malfunc-
tion
• A/T vehicle speed sensor mal- function CCS-40
Revision: March 2010
2008 QX56

DLK-54
< COMPONENT DIAGNOSIS >[WITH INTELLIGENT KEY SYSTEM]
U1000 CAN COMM CIRCUIT
COMPONENT DIAGNOSIS
U1000 CAN COMM CIRCUIT
DescriptionINFOID:0000000001538940
CAN (Controller Area Network) is a serial communication
line for real time applications. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Modern
vehicle is equipped with many electronic control unit, and each control unit shares information and links with
other control units during operation (not independent). In CAN communication, control units are connected
with 2 communication lines (CAN H-line, CAN L-line) allowing a high rate of information transmission with less
wiring. Each control unit transmits/receives data but selectively reads required data only.
CAN Communication Signal Chart. Refer to LAN-44, "
CAN Communication Signal Chart".
DTC LogicINFOID:0000000001538941
DTC DETECTION LOGIC
Diagnosis ProcedureINFOID:0000000001538942
1.PERFORM SELF DIAGNOSTIC
1. Turn ignition switch ON and wait for 2 second or more.
2. Check “Self Diagnostic Result”.
Is
“CAN COMM CIRCUIT” displayed?
YES >> Refer to LAN-14, "Trouble Diagnosis Flow Chart".
NO >> Refer to GI-38, "
Intermittent Incident".
DTCCONSULT-III display
description DTC Detection Condition
Possible cause
U1000 CAN COMM CIRCUIT When BCM cannot communicate CAN com-
munication signal continuously for 2 sec-
onds or more. In CAN communication system, any item (or items)
of the following listed below is malfunctioning.
•Transmission
• Receiving (ECM)
• Receiving (VDC/TCS/ABS)
• Receiving (METER/M&A)
• Receiving (TCM)
• Receiving (MULTI AV)
• Receiving (IPDM E/R)
Revision: March 2010
2008 QX56

DLN-1
TRANSMISSION & DRIVELINE
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CONTENTS
DRIVELINE
ATX14B
BASIC INSPECTION ....... .............................
6
DIAGNOSIS AND REPAIR WORKFLOW ..... .....6
Work Flow ........................................................... ......6
Preliminary Check .....................................................7
FUNCTION DIAGNOSIS ..............................10
4WD SYSTEM ................................................ ....10
System Diagram .................................................. ....10
System Description .................................................11
Component Parts Location ......................................16
CAN Communication ...............................................17
DIAGNOSIS SYSTEM (TRANSFER CON-
TROL UNIT) ........................................................
18
CONSULT-III Function (ALL MODE AWD/4WD) ....18
COMPONENT DIAGNOSIS .........................22
P1811 POWER SUPPLY CIRCUIT FOR
TRANSFER CONTROL UNIT ........................ ....
22
Description .......................................................... ....22
DTC Logic ...............................................................22
Diagnosis Procedure ...............................................22
Component Inspection ............................................23
P1802 – P1804, P1809 TRANSFER CON-
TROL UNIT .........................................................
24
Description ..............................................................24
DTC Logic ...............................................................24
Diagnosis Procedure ...............................................24
P1807 VEHICLE SPEED SENSOR (A/T) ..........26
Description .......................................................... ....26
DTC Logic ...............................................................26
Diagnosis Procedure ...............................................26
P1808 VEHICLE SPEED SENSOR (ABS) .........27
Description .......................................................... ....27
DTC Logic ............................................................ ....27
Diagnosis Procedure ...............................................27
P1810 NEUTRAL-4LO SWITCH .......................28
Description ...............................................................28
DTC Logic ................................................................28
Diagnosis Procedure ...............................................28
Component Inspection .............................................30
P1813 4WD SHIFT SWITCH .............................31
Description ...............................................................31
DTC Logic ................................................................31
Diagnosis Procedure ...............................................31
Component Inspection .............................................33
P1814 WAIT DETECTION SWITCH .................35
Description ...............................................................35
DTC Logic ................................................................35
Diagnosis Procedure ...............................................35
Component Inspection .............................................37
P1816 PNP SWITCH .........................................38
Description ...............................................................38
DTC Logic ................................................................38
Diagnosis Procedure ...............................................38
P1817 ACTUATOR MOTOR .............................39
Description ...............................................................39
DTC Logic ................................................................39
Diagnosis Procedure ...............................................39
Component Inspection .............................................43
P1818 ACTUATOR POSITION SWITCH ..........45
Description ...............................................................45
DTC Logic ................................................................45
Diagnosis Procedure ...............................................45
Component Inspection .............................................47
P1819 TRANSFER CONTROL DEVICE ...........48
Description ...............................................................48
DTC Logic ................................................................48
Diagnosis Procedure ...........................................
....48
Revision: March 2010 2008 QX56

4WD SYSTEMDLN-11
< FUNCTION DIAGNOSIS > [ATX14B]
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CONTROL SYSTEM
ABS actuator and electric unit
(control unit) Transmits vehicle speed signal via CAN communication to transfer control unit.
TCM Transmits the following signal via CAN communication to transfer control unit.
• Output speed sensor signal
• A/T position indicator signal (transmission range switch signal)
ECM Transmits the following signals via CAN communication to transfer control unit.
• Engine speed signal
• Accelerator pedal position signal
Components
Function
Revision: March 2010 2008 QX56

DLN-14
< FUNCTION DIAGNOSIS >[ATX14B]
4WD SYSTEM
• Displays 4LO condition while engine is running. 4LO indicator lamp flashes if transfer gear does not shift
completely under 2WD, AUTO, 4H ⇔4LO. (When 4WD warning lamp is turned on, 4LO indicator lamp is
turned off.)
• Turns ON for approximately 1 second when ignition switch is turned ON, for purpose of lamp check.
4WD WARNING LAMP
Turns on or flashes when there is a malfunction in 4WD system.
Also turns on when ignition switch is turned ON, for purpose of lamp che\
ck. Turns OFF approximately 1 sec-
ond after the engine starts if system is normal.
4WD Warning Lamp Indication
ATP WARNING LAMP
When the A/T selector lever is in P position, the vehicle may move if the transfer case is in neutral. ATP warn-
ing lamp is turned on to indicate this condition to the driver.
LINE PRESSURE SWITCH
• With the transfer system design, control of the oil pressure provides the transmission of drive torque to the
front wheels. The main pressure to control the oil pressure is referred to as the line pressure.
• The line pressure switch determines whether or not adequate line pressure has built up under different oper- ating conditions.
• The line pressure switch closes when line pressure is produced.
• The line pressure switch senses line pressure abnormalities and turns the 4WD warning lamp ON.
CLUTCH PRESSURE SWITCH
• The clutch pressure switch determines whether or not adequate clutch pressure has built up under different
operating conditions.
• The clutch pressure switch closes when clutch pressure is produced.
• The clutch pressure switch senses clutch pressure abnormalities and turns the 4WD warning lamp ON.
WAIT DETECTION SWITCH
• The wait detection switch operates when there is circulating torque produced in the propeller shaft (L→H) or
when there is a phase difference between 2-4 sleeve and clutch drum (H →L). After the release of the circu-
lating torque, the wait detection switch helps provi de the 4WD lock gear (clutch drum) shifts. A difference
may occur between the operation of the 4WD shift swit ch and actual drive mode. At this point, the wait
detection switch senses an actual drive mode.
• The wait detection switch operates as follows.
- 4WD lock gear (clutch drum) locked: ON
- 4WD lock gear (clutch drum) released: OFF
• The wait detection switch senses an actual drive mode and the 4WD shift indicator lamp indicates the vehi-
cle drive mode.
ATP SWITCH
ATP switch detects if transfer case is in neutral by the position of the L-H shift fork.
NOTE:
Transfer case may be in neutral when shifting between 4H-4LO.
NEUTRAL-4LO SWITCH
The neutral-4LO switch detects that transfer gear is in neutral or 4LO (or shifting from neutral to 4LO) condi-
tion by L-H shift fork position.
Condition 4WD warning lamp
System normal OFF
Lamp check Turns ON when ignition switch is turned ON.
Turns OFF after engine start.
4WD system malfunction ON
During self-diagnosis Flashes malfunction mode.
Large difference in diameter of front/
rear tires Flashes slow (1 flash / 2 seconds)
(Continues to flash until the ignition switch is turned OFF)
High fluid temperature in transfer case Flashes rapidly (2 flashes / 1 second)
(Continues to flash until fluid temperature returns to normal)
Revision: March 2010 2008 QX56

4WD SYSTEMDLN-15
< FUNCTION DIAGNOSIS > [ATX14B]
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TRANSFER FLUID TEMPERATURE SENSOR
The transfer fluid temperature sensor detects the trans fer fluid temperature and sends a signal to the transfer
control unit.
TRANSFER MOTOR
• The transfer motor drives the sub-oil pump to provi de proper lubrication and oil pressure control when the
vehicle is at standstill, during low-speed operations or is being driven in reverse.
• The main oil pump is operated by the driving force of t he mainshaft. In other words, sufficient oil pressure
buildup does not occur when the vehicle is at standsti ll or during low-speed operations. While the vehicle is
being driven in reverse, the main oil pump rotates in the reverse direction. Therefore the main oil pump does
not discharge oil pressure. During any of the above vehi cle operations, the transfer motor drives the sub-oil
pump to compensate for insufficient oil pressure.
• The transfer motor operates as follows:
- The motor relay turns OFF in the 2WD mode.
- The motor relay operates as described in the table below in modes other than the 2WD mode.
• 4WD shift switch, transmission range switch, Neutral-4LO switch, vehicle speed sensor and throttle position
sensor are used in conjunction with the transfer motor.
Transfer Motor Relay Operation
*: After 2.5 seconds have elapsed.
CLUTCH PRESSURE SOLENOID VALVE
The clutch pressure solenoid valve distributes front and rear torque in AUTO mode.
2-4WD SHIFT SOLENOID VALVE
The 2-4WD shift solenoid valve operates to apply oil pressure to the wet-multiplate clutch, depending on the
drive mode. The driving force is transmitted to the front wheels through the clutch so the vehicle is set in the
4WD mode. Setting the vehicle in the 2WD mode requires no pressure buildup. In other words, pressure force
applied to the wet-multiplate clutch becomes zero.
TRANSFER CONTROL DEVICE
Integrates actuator motor and actuator position switch.
4WD shift switch A/T selector lever position Vehicle speed
(VSS) Accelerator pedal position Motor relay drive
command
2WD ———OFF
4H (LOCK) and 4LO N position
0— ON
P position 00 - 0.07/8
OFF*
0.07/8 - 1/8 HOLD
1/8 - MAX ON
Other than R position 0 < VSS ≤
50 km/h (31 MPH)
— ON
50 km/h (31 MPH) < VSS < 55 km/h (34 MPH) HOLD
55 km/h (34 MPH) ≤ VSS OFF
R position —— ON
R position —— ON
AUTO P or N position 0
0 - 0.07/8
OFF*
0.07/8 - 1/8 HOLD
1/8 - MAX ON
0 < VSS ≤ 50 km/h (31 MPH)
— ON
50 km/h (31 MPH) < VSS < 55 km/h (34 MPH) HOLD
55 km/h (34 MPH) ≤ VSS OFF
Other than R, P and N posi-
tion 0 < VSS ≤
50 km/h (31 MPH)
— ON
50 km/h (31 MPH) < VSS < 55 km/h (34 MPH) HOLD
55 km/h (34 MPH) ≤ VSS OFF
Revision: March 2010 2008 QX56