2010 INFINITI QX56 ABS

DLN-1
TRANSMISSION & DRIVELINE
CEF
G H
I
J
K L
M
SECTION DLN
A
B
DLN
N
O P
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 .........................................................
25
Description ..............................................................25
DTC Logic ...............................................................25
Diagnosis Procedure ...............................................25
P1807 VEHICLE SPEED SENSOR (A/T) ..........27
Description .......................................................... ....27
DTC Logic ...............................................................27
Diagnosis Procedure ...............................................27
P1808 VEHICLE SPEED SENSOR (ABS) .........28
Description .......................................................... ....28
DTC Logic ............................................................ ....28
Diagnosis Procedure ...............................................28
P1810 NEUTRAL-4LO SWITCH .......................29
Description ...............................................................29
DTC Logic ................................................................29
Diagnosis Procedure ...............................................29
Component Inspection .............................................31
P1813 4WD SHIFT SWITCH .............................32
Description ...............................................................32
DTC Logic ................................................................32
Diagnosis Procedure ...............................................32
Component Inspection .............................................34
P1814 WAIT DETECTION SWITCH .................36
Description ...............................................................36
DTC Logic ................................................................36
Diagnosis Procedure ...............................................36
Component Inspection .............................................38
P1816 TRANSMISSION RANGE SWITCH .......39
Description ...............................................................39
DTC Logic ................................................................39
Diagnosis Procedure ...............................................39
P1817 ACTUATOR MOTOR .............................40
Description ...............................................................40
DTC Logic ................................................................40
Diagnosis Procedure ...............................................40
Component Inspection .............................................44
P1818 ACTUATOR POSITION SWITCH ..........46
Description ...............................................................46
DTC Logic ................................................................46
Diagnosis Procedure ...............................................46
Component Inspection .............................................48
P1819 TRANSFER CONTROL DEVICE ...........49
Description ...............................................................49
DTC Logic ................................................................49
Diagnosis Procedure ...........................................
....49
Revision: April 20092010 QX56

DLN-2
P1820 ENGINE SPEED SIGNAL ......................53
Description ........................................................... ...53
DTC Logic ...............................................................53
Diagnosis Procedure ..............................................53
P1822 CLUTCH PRESSURE SOLENOID .........54
Description ..............................................................54
DTC Logic ...............................................................54
Diagnosis Procedure ..............................................54
Component Inspection ............................................57
P1823 2-4 SOLENOID .......................................58
Description ........................................................... ...58
DTC Logic ...............................................................58
Diagnosis Procedure ..............................................58
Component Inspection ............................................61
P1824 TRANSFER MOTOR ..............................62
Description ..............................................................62
DTC Logic ...............................................................62
Diagnosis Procedure ..............................................62
Component Inspection ............................................66
P1826 TRANSFER FLUID TEMPERATURE ....68
Description ........................................................... ...68
DTC Logic ...............................................................68
Diagnosis Procedure ..............................................68
Component Inspection ............................................69
P1827 CLUTCH PRESSURE SWITCH .............71
Description ........................................................... ...71
DTC Logic ...............................................................71
Diagnosis Procedure ..............................................71
Component Inspection ............................................73
P1828 LINE PRESSURE SWITCH ....................74
Description ........................................................... ...74
DTC Logic ...............................................................74
Diagnosis Procedure ..............................................74
Component Inspection ............................................76
P1829 THROTTLE POSITION SIGNAL (ECM)
...
77
Description ........................................................... ...77
DTC Logic ...............................................................77
Diagnosis Procedure ..............................................77
P1830 ABS OPERATION SIGNAL (ABS) ........78
Description ........................................................... ...78
DTC Logic ...............................................................78
Diagnosis Procedure ..............................................78
P1831 VDC OPERATION SIGNAL (ABS) ........79
Description ........................................................... ...79
DTC Logic ...............................................................79
Diagnosis Procedure ..............................................79
P1832 TCS OPERATION SIGNAL (ABS) .........80
Description ........................................................... ...80
DTC Logic ...............................................................80
Diagnosis Procedure ..............................................80
ECU DIAGNOSIS .......................................81
TRANSFER CONTROL UNIT ...........................81
Reference Value .................................................. ...81
Wiring Diagram - ALL-MODE 4WD SYSTEM - .... ...89
DTC Index ............................................................ ...97
SYMPTOM DIAGNOSIS ...........................102
4WD SYSTEM SYMPTOMS ........................... ..102
Symptom Table .................................................... .102
4WD SHIFT INDICATOR LAMP AND 4LO IN-
DICATOR LAMP DO NOT TURN ON ..............
103
Description ............................................................103
Diagnosis Procedure .............................................103
4WD WARNING LAMP DOES NOT TURN ON ..105
Description ........................................................... .105
Diagnosis Procedure .............................................105
4WD SHIFT INDICATOR LAMP OR 4LO INDI-
CATOR LAMP DO NOT CHANGE ...................
107
Description ........................................................... .107
Diagnosis Procedure .............................................107
ATP WARNING LAMP DOES NOT TURN ON ..109
Description ........................................................... .109
Diagnosis Procedure .............................................109
4WD SHIFT INDICATOR LAMP KEEPS
FLASHING ........................................................
111
Description ........................................................... .111
Diagnosis Procedure .............................................111
4WD WARNING LAMP FLASHES RAPIDLY ..112
Description ............................................................112
Diagnosis Procedure .............................................112
4WD WARNING LAMP FLASHES SLOWLY ..113
Description ............................................................113
Diagnosis Procedure .............................................113
HEAVY TIGHT-CORNER BRAKING SYMP-
TOM OCCURS ................................................ ..
114
Description ........................................................... .114
Diagnosis Procedure .............................................114
ATP SWITCH ....................................................116
Description ........................................................... .116
Diagnosis Procedure .............................................116
4WD SYSTEM DOES NOT OPERATE ............118
Description ........................................................... .118
Diagnosis Procedure .............................................118
NOISE, VIBRATION AND HARSHNESS
(NVH) TROUBLESHOOTING ...........................
119
NVH Troubleshooting Chart ..................................119
PRECAUTION ............... ............................120
Revision: April 20092010 QX56

4WD SYSTEMDLN-11
< FUNCTION DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O PSystem DescriptionINFOID:0000000005148771
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 shaft revolution 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: April 20092010 QX56

DIAGNOSIS SYSTEM (TRANSFER CONTROL UNIT)DLN-19
< FUNCTION DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
12. Move A/T selector lever to N position.
13. Turn 4WD shift switch to AUTO position.
14. Move A/T selector lever to P position.
15. Read the flickering of 4WD warning lamp.
Self-diagnosis example
ERASE SELF-DIAGNOSIS
• In order to make it easier to find the cause of hard-to-duplicate malfunctions, malfunction information is
stored into the control unit as necessary during use by the user. This memory is not erased no matter how
many times the ignition switch is turned ON and OFF.
• However, this information is erased by turning igni tion switch OFF after performing self-diagnostics or by
erasing the memory using the CONSULT-III.
DATA MONITOR MODE
Operation Procedure
1. Connect CONSULT-III.
2. Touch DATA MONITOR.
3. Select from SELECT MONITOR ITEM, screen of data monitor mode is displayed.
NOTE:
When malfunction is detected, CONSUL T-III performs REAL-TIME DIAGNOSIS.
Also, any malfunction detected while in th is mode will be displayed at real time.
Display Item List
×: Standard –: Not applicable
PDIA0227E
Monitored item (Unit) Monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELEC-
TION FROM MENU
VHCL/S SEN·FR [km/h] or [mph] ×–×Wheel speed calculated by ABS actuator and
electric unit (control unit).
Signal input with CAN communication line.
VHCL/S SEN·RR [km/h] or [mph] ×–×Wheel speed calculated by TCM.
Signal input with CAN communication line.
ENGINE SPEED [rpm] ×–×Engine speed calculated by ECM.
Signal input with CAN communication line.
THRTL POS SEN [V] ×–×Accelerator peda
l position (APP) sensor sig-
nal voltage is displayed.
Signal input with CAN communication line.
FLUID TEMP SE [V] ×–×Transfer fluid temperature sensor signal volt-
age is displayed.
BATTERY VOLT [V] ×–×Power supply voltage for transfer control unit.
2WD SWITCH [On/Off] ×–×4WD shift switch status is displayed.
AUTO SWITCH [On/Off] ×–×4WD shift switch status is displayed.
LOCK SWITCH [On/Off] ×–×4WD shift switch status is displayed.
(LOCK means 4H of 4WD shift switch.)
Revision: April 20092010 QX56

DLN-20
< FUNCTION DIAGNOSIS >[ATX14B]
DIAGNOSIS SYSTEM (T
RANSFER CONTROL UNIT)
4L SW [On/Off] ×–×4WD shift switch status is displayed.
(4L means 4LO of 4WD shift switch.)
N POSI SW TF [On/Off] ×–×Neutral-4LO switch signal status is displayed.
ATP SWITCH [On/Off] ×–×ATP switch signal status is displayed.
WAIT DETCT SW [On/Off] ×–×Wait detection switch status is displayed.
LINE PRES SW [On/Off] ×–×Line pressure switch status is displayed.
CL PRES SW [On/Off] ×–×Clutch pressure switch status is displayed.
N POSI SW AT [On/Off] ×–×N position signal of transmission range switch
status is displayed.
Signal input with CAN communication line.
R POSI SW AT [On/Off] ×–×R position signal of transmission range switch
status is displayed.
Signal input with CAN communication line.
P POSI SW AT [On/Off] ×–×P position signal of transmission range switch
status is displayed.
Signal input with CAN communication line.
ABS OPER SW [On/Off] ×–×ABS operation signal status is displayed.
Signal input with CAN communication line.
VDC OPER SW [On/Off] ×–×VDC operation signal status is displayed.
Signal input with CAN communication line.
TCS OPER SW [On/Off] ×–×TCS operation signal status is displayed.
Signal input with CAN communication line.
THROTTLE POSI [0.0/8] –×× Thottle position status is displayed.
Signal input with CAN communication line.
4WD MODE [AUTO/LOCK/2WD/4L] – ××Control status of 4WD recognized by transfer
control unit. (AUTO, 4H, 2WD or 4LO)
VHCL/S COMP [km/h] or [mph] –×× Vehicle speed recognized by transfer control
unit.
COMP CL TORQ [kgm] –×× Calculated torque recognized by transfer con-
trol unit.
DUTY SOLENOID [%] –×× Control value of clutch pressure solenoid.
2-4WD SOL [On/Off] –×× Output condition to 2-4WD solenoid.
2-4WD SOL MON [On/Off] ––×Check signal for transfer control unit signal
output.
MOTOR RELAY [On/Off] –×× Transfer motor relay signal status is dis-
played.
MOTOR RELAY MON [On/Off] ––×Check signal for transfer control unit signal
ou
t

put.
4WD FAIL LAMP [On/Off] –×× Control status of 4WD warning lamp is dis-
played.
2WD IND [On/Off] ––×Control status of 4WD shift indicator lamp
(2WD indicator lamp) is displayed.
AUTO IND [On/Off] ––×Control status of 4WD shift indicator lamp
(2WD and AUTO indicator lamp) is displayed.
LOCK IND [On/Off] ––×Control status of 4WD shift indicator lamp
(2WD, AUTO and Lock indicator) is displayed.
4L IND [On/Off] ––×Control status of 4LO indicator lamp is dis-
played.
Monitored item (Unit)
Monitor item selection
Remarks
ECU INPUT
SIGNALS MAIN
SIGNALS SELEC-
TION FROM
MENU
Revision: April 20092010 QX56

DLN-28
< COMPONENT DIAGNOSIS >[ATX14B]
P1808 VEHICLE SPEED
SENSOR (ABS)
P1808 VEHICLE SPEED SENSOR (ABS)
DescriptionINFOID:0000000005148785
The ABS actuator and electric unit (control unit) tr ansmits a vehicle speed signal via CAN communication to
the transfer control unit. DTC P1808 sets when a malfunction is detected in the vehicle speed signal that is
output from the ABS actuator and elec tric unit (control unit) or an improper signal is input while driving.
DTC LogicINFOID:0000000005148786
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1808 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-28, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148787
1.CHECK DTC WITH ABS ACTUATOR AN D ELECTRIC UNIT (CONTROL UNIT)
Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to BRC-23, "
CONSULT-III
Function (ABS)".
Is any malfunction detec ted by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 2.
2.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 3.
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.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
Are the inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with ABS actuator and electric unit (control unit) again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1808] VHCL SPEED SEN·ABS • Malfunction is detected in vehicle
speed signal that is output from ABS
actuator and electric unit (control unit)
through CAN communication.
• Improper signal is input while driving. Refer to
DLN-28
.
Revision: April 20092010 QX56

DLN-78
< COMPONENT DIAGNOSIS >[ATX14B]
P1830 ABS OPERATION SIGNAL (ABS)
P1830 ABS OPERATION SIGNAL (ABS)
DescriptionINFOID:0000000005148844
Malfunction is detected in ABS operation signal that is
output from ABS actuator and electric unit (control unit)
through CAN communication.
DTC LogicINFOID:0000000005148845
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1830 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-78, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148846
1.CHECK DTC WITH ABS ACTUATOR AN D ELECTRIC UNIT (CONTROL UNIT)
Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to BRC-23, "
CONSULT-III
Function (ABS)".
Is any malfunction detec ted by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 2.
2.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 3.
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.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
Are the inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with ABS actuator and electric unit (control unit) again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1830] ABS OP SIG Malfunction is detect
ed in ABS operation
signal that is outp ut from ABS actuator
and electric unit (control unit) through
CAN communication. Refer to
DLN-78
.
Revision: April 20092010 QX56

P1831 VDC OPERATION SIGNAL (ABS)DLN-79
< COMPONENT DIAGNOSIS > [ATX14B]
C
EF
G H
I
J
K L
M A
B
DLN
N
O P
P1831 VDC OPERATION SIGNAL (ABS)
DescriptionINFOID:0000000005148847
Malfunction is detected in the VDC operation signal that is output from ABS actuator and electric unit (control
unit) through CAN communication.
DTC LogicINFOID:0000000005148848
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Perform self-diagnosis.
Is DTC P1831 displayed?
YES >> Perform diagnosis procedure. Refer to DLN-79, "Diagnosis Procedure".
NO >> Inspection End.
Diagnosis ProcedureINFOID:0000000005148849
1.CHECK DTC WITH ABS ACTUATOR AND ELECTRIC UNIT
Perform self-diagnosis with ABS actuator and electric unit (control unit). Refer to BRC-23, "
CONSULT-III
Function (ABS)".
Is any malfunction detected by self-diagnosis?
YES >> Check the malfunctioning system.
NO >> GO TO 2.
2.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 3.
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.
3.CHECK DTC
Perform the self-diagnosis, after driving a vehicle for a while.
Are the inspection results normal?
YES >> Inspection End.
NO >> Perform self-diagnosis with ABS actuator electric unit (control unit) again.
DTC CONSULT-III Diagnostic item is detected when... Reference
[P1831] VDC OP SIG Malfunction is detected in VDC opera-
tion signal that is output from ABS actu-
ator and electric unit (control unit)
through CAN communication.Refer to DLN-79
.
Revision: April 20092010 QX56