2010 INFINITI QX56 diagram

STR-10
< COMPONENT DIAGNOSIS >
B TERMINAL CIRCUIT
COMPONENT DIAGNOSIS
B TERMINAL CIRCUIT
DescriptionINFOID:0000000005149554
Terminal "2" (B) is constantly supplied with battery power.
Diagnosis ProcedureINFOID:0000000005149555
Regarding Wiring Diagram information, refer to STR-14, "Wiring Diagram".
CAUTION:
Perform diagnosis under the condi tion that the engine cannot start by the following procedure.
1. Remove fuel pump fuse.
2. Crank or start the engine (where possible) until the fuel pressure is depleted.
1.CHECK TERMINAL 2 POWER SUPPLY VOLTAGE
1. Turn ignition switch OFF.
2. Make sure that starter motor connector F27 terminal 2 connection is clean and tight.
3. Check voltage between starter motor connector F27 terminal 2
and ground.
Is there battery voltage present?
YES >> GO TO 2
NO >> Check harness between battery and starter motor for open circuit.
2.CHECK BATTERY CABLE (VOLTAGE DROP TEST)
1. Shift the transmission into park or neutral.
2. Check voltage between battery positive terminal and starter motor connector F27 terminal 2 while cranking the engine.
Is the voltage drop less than 0.2V?
YES >> GO TO 3
NO >> Check harness between the battery and the starter motor for high resistance.
3.CHECK GROUND CIRCUIT STATUS (VOLTAGE DROP TEST)
(+) (-)Condition Voltage
Connector Terminal
F27 2 Ground While cranking the
engine Battery voltage
AWBIA0122GB
(+)
(-)Condition Voltage
Connector Terminal
F27 2 Battery (+)
terminal While cranking the
engine Less than 0.2V
AWBIA0123GB
Revision: April 20092010 QX56

STR-12
< COMPONENT DIAGNOSIS >
S CONNECTOR CIRCUIT
S CONNECTOR CIRCUIT
DescriptionINFOID:0000000005149556
Terminal "1" (S) is the power supply for the starter motor magnetic switch. Terminal 1 is supplied with power
when the ignition switch is turned to the START position while the selector lever is in the P or N position.
Diagnosis ProcedureINFOID:0000000005149557
Regarding Wiring Diagram information, refer to STR-14, "Wiring Diagram".
CAUTION:
Perform diagnosis under the condi tion that engine cannot start by the following procedure.
1. Remove fuel pump fuse.
2. Crank or start the engine (where possi ble) until the fuel pressure is released.
1.CHECK STARTER MOTOR MAGNETIC SWITCH CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect starter motor connector F28.
3. Shift transmission into park or neutral.
4. Check voltage between starter motor harness connector F28 terminal 1 and ground with the ignition in START.
Is battery voltage present?
YES >> Magnetic switch circuit is OK. Further inspection necessary. Refer to STR-5, "Work Flow".
NO >> GO TO 2
2.CHECK CONNECTOR
1. Turn ignition switch OFF.
2. Check the IPDM E/R harness connector E120 and st arter motor harness connector F28 for damage, bent
pins and loose connections.
Is the inspection result normal?
YES >> GO TO 3
NO >> Repair the terminal and connector.
3.CHECK HARNESS CONTI NUITY (OPEN CIRCUIT)
1. Disconnect IPDM E/R connector E120 and starter motor con- nector F28.
2. Check continuity between starter motor harness connector F28
(A) terminal 1 and IPDM E/R harness connector E120 (B) termi-
nal 19.
3. Check continuity between starter motor harness connector F28 (A) terminal 1 and ground.
(+) (-)Condition Voltage
Connector Terminal
F28 1 Ground Ignition in START Battery voltage
AWBIA0125GB
AB Continuity
Connector Terminal Connector Terminal
F28 1E120 19 Yes
A —Contin u it y
Connector Terminal
F28 1Ground No
AWBIA0126GB
Revision: April 20092010 QX56

STR-14
< COMPONENT DIAGNOSIS >
STARTING SYSTEM
STARTING SYSTEM
Wiring DiagramINFOID:0000000005149558
ABBWA0118GB
Revision: April 20092010 QX56

TM-3
CEF
G H
I
J
K L
M A
B
TM
N
O P
Diagnosis Procedure ...........................................
....
80
P1752 INPUT CLUTCH SOLENOID ..................82
Description .......................................................... ....82
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
82
On Board Diagnosis Logic ......................................82
Possible Cause .......................................................82
DTC Confirmation Procedure ..................................82
Diagnosis Procedure ...............................................82
P1757 FRONT BRAKE SOLENOID ...................84
Description .......................................................... ....84
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
84
On Board Diagnosis Logic ......................................84
Possible Cause .......................................................84
DTC Confirmation Procedure ..................................84
Diagnosis Procedure ...............................................84
P1762 DIRECT CLUTCH SOLENOID ................86
Description .......................................................... ....86
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
86
On Board Diagnosis Logic ......................................86
Possible Cause .......................................................86
DTC Confirmation Procedure ..................................86
Diagnosis Procedure ...............................................86
P1767 HIGH AND LOW REVERSE CLUTCH
SOLENOID .........................................................
88
Description .......................................................... ....88
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
88
On Board Diagnosis Logic ......................................88
Possible Cause .......................................................88
DTC Confirmation Procedure ..................................88
Diagnosis Procedure ...............................................88
P1772 LOW COAST BRAKE SOLENOID .........90
Description .......................................................... ....90
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
90
On Board Diagnosis Logic ......................................90
Possible Cause .......................................................90
DTC Confirmation Procedure ..................................90
Diagnosis Procedure ...............................................90
P1774 LOW COAST BRAKE SOLENOID .........92
Description .......................................................... ....92
CONSULT-III Reference Value in Data Monitor
Mode ................................................................... ....
92
On Board Diagnosis Logic ......................................92
Possible Cause .......................................................92
DTC Confirmation Procedure ..................................92
Diagnosis Procedure ...............................................93
MAIN POWER SUPPLY AND GROUND CIR-
CUIT ....................................................................
94
Diagnosis Procedure ........................................... ....94
CLOSED THROTTLE POSITION AND WIDE
OPEN THROTTLE POSITION CIRCUIT ...........
96
CONSULT-III Reference Value in Data Monitor
Mode .................................................................... ....
96
Diagnosis Procedure ...............................................96
BRAKE SIGNAL CIRCUIT ................................97
CONSULT-III Reference Va lue in Data Monitor
Mode .................................................................... ....
97
Diagnosis Procedure ...............................................97
TOW MODE SWITCH .......................................98
Description ...............................................................98
Diagnosis Procedure ...............................................98
A/T SHIFT LOCK SYSTEM ...............................99
Description ...............................................................99
Terminals And Reference Values ............................99
Wiring Diagram - A/T SH IFT LOCK SYSTEM - .....100
Component Inspection ......................................... ..103
ECU DIAGNOSIS .......................................106
TCM .................................................................106
Reference Value .................................................. ..106
Wiring Diagram — A/T CONTROL SYSTEM — .. ..108
Fail-Safe .............................................................. ..117
DTC Inspection Priority Chart ................................119
DTC No. Index .......................................................119
DTC Alphabetical Index .........................................120
SYMPTOM DIAGNOSIS ............................121
SYSTEM SYMPTOM .......................................121
Symptom Table ................................................... ..121
PRECAUTION ............................................143
PRECAUTIONS ...............................................143
Precaution for Supplemental Restraint System
(SRS) "AIR BAG" and "SEAT BELT PRE-TEN-
SIONER" ............................................................. ..
143
Precaution for On Board Diagnosis (OBD) System
of A/T and Engine ................................................ ..
143
Precaution .............................................................143
Service Notice or Precaution .................................144
PREPARATION .........................................146
PREPARATION ...............................................146
Special Service Tool ............................................ ..146
Commercial Service Tool ......................................147
ON-VEHICLE MAINTENANCE ..................148
A/T FLUID .......................................................148
Checking the A/T Fluid (ATF) .............................. ..148
Changing the A/T Fluid (ATF) ................................150
A/T FLUID COOLER .......................................152
A/T Fluid Cooler Cleaning .....................................152
Inspection ..............................................................154
Revision: April 20092010 QX56

A/T CONTROL SYSTEMTM-21
< FUNCTION DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
CONTROL SYSTEM DIAGRAM
CAN CommunicationINFOID:0000000005148511
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, 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. For details, refer to LAN-4,
"System Description".
SENSORS (or SIGNALS)
⇒TCM
⇒ACTUATORS
Transmission range switch
Accelerator pedal position sensor
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Output speed sensor
Vehicle speed signal
Stop lamp switch signal
Input speed sensor
1st position switch signal
4th position switch signal
ATF pressure switch 2 signal
Tow mode switch signal Shift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-III co
mmunication
line
Duet-EA control
CAN system Input clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch sole-
noid valve
Low coast brake solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
A/T CHECK indicator lamp
Starter relay
Back-up lamp relay
JSDIA1315GB
Revision: April 20092010 QX56

TM-24
< FUNCTION DIAGNOSIS >
A/T CONTROL SYSTEM
The necessary and adequate line pressure for shift change is set.
For this reason, line pressure pattern setting corresponds to input
torque and gearshift selection. Also, line pressure characteristic is
set according to engine speed, during engine brake operation.
At Low Fluid Temperature
When the A/T fluid temperature drops below the prescribed tempera-
ture, in order to speed up the action of each friction element, the line
pressure is set higher than the normal line pressure characteristic.
Shift ControlINFOID:0000000005148514
The clutch pressure control solenoid is controlled by the signals from the switches and sensors. Thus, the
clutch pressure is adjusted to be appropriate to the engine load state and vehicle driving state. It becomes
possible to finely control the clutch hydraulic pressure with high precision and a smoother shift change charac-
teristic is attained.
SHIFT CHANGE
The clutch is controlled with the optimum timing and oil pressure by the engine speed, engine torque informa-
tion, etc.
Shift Change System Diagram
PCIA0010E
PCIA0011E
PCIA0012E
Revision: April 20092010 QX56

A/T CONTROL SYSTEMTM-25
< FUNCTION DIAGNOSIS >
CEF
G H
I
J
K L
M A
B
TM
N
O P
*1: Full phase real-time feedback control monitors move ment of gear ratio at gear change, and controls oil
pressure at real-time to achieve the best gear ratio.
Lock-up ControlINFOID:0000000005148515
The torque converter clutch piston in the torque conv erter is engaged to eliminate torque converter slip to
increase power transmission efficiency.
The torque converter clutch control valve operation is controlled by the torque conver ter clutch solenoid valve,
which is controlled by a signal from TCM, and the torque converter clutch control valve engages or releases
the torque converter clutch piston.
Lock-up Operation Condition Table
TORQUE CONVERTER CLUTCH CONTROL VALVE CONTROL
Lock-up Control System Diagram
Lock-up Released
• In the lock-up released state, the torque converter clutch control valve is set into the unlocked state by the
torque converter clutch solenoid and the lock-up apply pressure is drained.
In this way, the torque converter clutch piston is not coupled.
Lock-up Applied
• In the lock-up applied state, the torque converter clutch control valve is set into the locked state by the
torque converter clutch solenoid and lock-up apply pressure is generated.
In this way, the torque converter clutch piston is pressed and coupled.
SMOOTH LOCK-UP CONTROL
PCIA0013E
Select lever D position4 position 3 position 2 position
G ear p osit io n 54432
Lock-up ×– ×××
Slip lock-up ××–––
PCIA0014E
Revision: April 20092010 QX56

TM-100
< COMPONENT DIAGNOSIS >
A/T SHIFT LOCK SYSTEM
Wiring Diagram - A/T SHIFT LOCK SYSTEM -
INFOID:0000000005148685
ABDWA0116GB
Revision: April 20092010 QX56