2010 INFINITI QX56 ECU

POWER STEERING GEAR AND LINKAGEST-23
< REMOVAL AND INSTALLATION >
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POWER STEERING GEAR AND LINKAGE
Removal and InstallationINFOID:0000000005147873
CAUTION:
Spiral cable may snap due to steering operation if steering column is separated from steering gear
assembly. Therefore secure steer ing wheel to avoid turning.
REMOVAL
1. Turn wheels to the straight-ahead position.
2. Remove tires from vehicle using power tool.
3. Remove undercovers using power tool if equipped.
4. Remove front final drive, then support dr ive shafts with wire if equipped. Refer to DLN-215, "
Removal and
Installation".
5. Make sure slit of lower joint fits with the projection on rear cover cap, while checking that mark on steering gear assembly aligns
with mark on rear cover cap.
6. Remove cotter pin at steering outer socket and discard, then loosen nut.
1. Cotter pin 2. Steering gear bracket3. Steering gear insulator
4. Steering gear assembly 5. Washer
AWGIA0114GB
SST491C
Revision: April 20092010 QX56

POWER STEERING GEAR AND LINKAGEST-31
< DISASSEMBLY AND ASSEMBLY >
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POWER STEERING GEAR AND LINKAGE
Disassembly and AssemblyINFOID:0000000005147877
CAUTION:
• Secure steering gear assembly with a vise, using copper plates or something similar to prevent it
from being damaged. Do not grip cylinder with a vise.
• Before performing disassembly, clean steering gear assembly with kerosene. Be careful not to bring
any kerosene into contact with the di scharge and return port connectors.
DISASSEMBLY
1. Remove cylinder tubes from gear housing assembly.
2. Loosen lock nuts of outer sockets, and remove outer sockets.
3. Remove boot clamps of the small diameter si de and the large diameter side, then remove boot.
CAUTION:
When removing boots, be careful not to damage inner socket and gear housing assembly. If they
are damaged, change th em to avoid oil leaks.
4. Remove inner sockets.
INSPECTION AFTER DISASSEMBLY
Boot
Check boot for tears, cracks and deformation. Replace if necessary.
1. Boot clamp 2. Inner socket3. Boot
4. Boot clamp 5. Outer socket6. Cylinder tubes
7. Gear housing assembly 8. Connector
AWGIA0116GB
Revision: April 20092010 QX56

TM-3
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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 .........................................................
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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

TM-32
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (TCM)
DIAGNOSIS SYSTEM (TCM)
CONSULT-III Function (TRANSMISSION)INFOID:0000000005148526
CONSULT-III can display each diagnostic item us ing the diagnostic test modes shown following.
SELF-DIAGNOSTIC RESULT MODE
Display Items List
X: Applicable, —: Not applicable
TCM diagnostic mode Description
Work Support This mode enables a technician to adjust some devices faster and more accurately.
Self-Diagnostic Results Retrieve DTC from ECU and display diagnostic items.
Data Monitor Monitor the input/output signal of the control unit in real time.
CAN Diagnosis Support Monitor It monitors the status of CAN communication.
DTC & SRT Confirmation The status of system monitoring tests and the self-diagnosis status/result can be confirmed.
ECU Identification Display the ECU identification number (part number etc.) of the selected system.
Items (CONSULT-III
screen terms) Malfunction is detected when... TCM self-di-
agnosis OBD (DTC)
Reference
“TRANSMIS-
SION” with
CONSULT-III MIL indicator
lamp*1, “EN-
GINE” with
CONSULT-III or
GST
CAN COMM CIRCUIT • When a malfunction is detected in CAN communica-
tions. U1000 U1000
TM-40
STARTER RELAY• If this signal is ON other than in “P” or “N” position, this
is judged to be a malfunction.
(And if it is OFF in “P” or “N” position, this too is judged
to be a malfunction.) P0615
—TM-41
TRANSMISSION CON-
TROL • TCM is malfunctioning.
P0700 P0700TM-44
T/M RANGE SWITCH A• Transmission range switch 1-4 signals input with im-
possible pattern.
• “P” position is detected from “N” position without any other position being detected in between. P0705 P0705
TM-45
INPUT SPEED SEN-
SOR A• TCM does not receive the proper voltage signal from
the sensor.
• TCM detects an irregularity only at position of 4GR for input speed sensor 2. P0717 P0717
TM-48
OUTPUT SPEED SEN-
SOR• Signal from output speed not input due to cut line or
the like.
• Unexpected signal input during running.
• After ignition switch is turned ON, unexpected signal input from vehicle speed signal before the vehicle
starts moving. P0720 P0720
TM-51
ENGINE SPEED• TCM does not receive the CAN communication signal
from the ECM. P0725
—TM-53
1GR INCORRECT RA-
TIO • A/T cannot shift to 1GR.
P0731 P0731TM-56
2GR INCORRECT RA-
TIO• A/T cannot shift to 2GR.
P0732 P0732TM-58
3GR INCORRECT RA-
TIO• A/T cannot shift to 3GR.
P0733 P0733TM-60
Revision: April 20092010 QX56

TM-34
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (TCM)
*1: Refer to EC-55, "Malfunction Indicator Lamp (MIL)".
*2:These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL.
DATA MONITOR MODE
Display Items List
X: Standard, —: Not applicable
L C BRAKE SOLENOID • TCM detects an improper voltage drop when it tries to
operate the solenoid valve.
• Condition of ATF pressure switch 2 is different from
monitor value, and relation between gear position and
actual gear ratio is irregular. P1774 P1774*2
TM-93
NO DTC IS DETECTED
FURTHER TESTING
MAY BE REQUIRED• No NG item has been detected.
XX —
Items (CONSULT-III
screen terms) Malfunction is detected when... TCM self-di-
agnosis OBD (DTC)
Reference
“TRANSMIS-
SION” with
CONSULT-III MIL indicator
lamp*1, “EN-
GINE” with
CONSULT-III or
GST
Monitored item (Unit) Monitor Item Selection
Remarks
ECU IN-
PUT SIG-
NALS MAIN SIG-
NALS SELEC-
TION
FROM
MENU
VHCL/S SE-A/T (km/h) XXX Output speed sensor
VHCL/S SE-MTR (km/h) X— X —
ACCELE POSI (0.0/8) X— X Accelerator pedal position signal
THROTTLE POSI (0.0/8) XXXDegree of opening for accelerator recognized by
the TCM.
For fail-safe operation, the specific value used
for control is displayed.
CLSD THL POS (ON-OFF display) X— X
Signal input with CAN communications.
W/O THL POS (ON-OFF display) X— X
BRAKESW (ON-OFF display) X— X Stop lamp switch
GEAR —XXGear position recognized by the TCM updated
after gear-shifting.
ENGINE SPEED (rpm) XXX —
INPUT SPEED (rpm) XXX —
OUTPUT REV (rpm) XXX —
GEAR RATIO —XX —
TC SLIP SPEED (rpm) —XXDifference between engine speed and torque
converter input shaft speed.
F SUN GR REV (rpm) —— X —
F CARR GR REV (rpm) —— X —
ATF TEMP SE 1 (V) X— X —
ATF TEMP 1 (° C) —XX —
ATF TEMP 2 (° C) —XX —
BATTERY VOLT (V) X— X —
ATF PRES SW 1 (ON-OFF display) XXX —
ATF PRES SW 2 (ON-OFF display) XXX (for LC/B solenoid)
Revision: April 20092010 QX56

DIAGNOSIS SYSTEM (TCM)TM-35
< FUNCTION DIAGNOSIS >
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ATF PRES SW 3 (ON-OFF display) XX X —
ATF PRES SW 5 (ON-OFF display) XX X —
ATF PRES SW 6 (ON-OFF display) XX X —
RANGE SW 1 (ON-OFF display) X— X —
RANGE SW 2 (ON-OFF display) X— X —
RANGE SW 3 (ON-OFF display) X— X —
RANGE SW 4 (ON-OFF display) X— X —
SLCT LVR POSI —XXSelector lever position is recognized by the TCM.
For fail-safe operation, the specific value used
for control is displayed.
1 POSITION SW (ON-OFF display) X— X 1st position switch
OD CONT SW (ON-OFF display) X— X 4th position switch
POWERSHIFT SW (ON-OFF display) X —X
Not mounted but displayed.
HOLD SW (ON-OFF display)
X— X
DS RANGE (ON-OFF display) —— X
MANU MODE SW (ON-OFF display) X— X
NON M-MODE SW (ON-OFF display) X —X
UP SW LEVER (ON-OFF display) X— X
DOWN SW LEVER (ON-OFF display) X —X
SFT UP ST SW (ON-OFF display) —— X
SFT DWN ST SW (ON-OFF display) — —X
ASCD-OD CUT (ON-OFF display) —— X —
ASCD-CRUISE (ON-OFF display) —— X —
ABS SIGNAL (ON-OFF display) —— X —
ACC OD CUT (ON-OFF display) —— X
ICC (Intelligent cruise control)
ACC SIGNAL (ON-OFF display) —— X
TCS GR/P KEEP (ON-OFF display) —— X —
TCS SIGNAL 2 (ON-OFF display) —— X —
TCS SIGNAL 1 (ON-OFF display) —— X —
TCC SOLENOID (A) —XX —
LINE PRES SOL (A) —XX —
I/C SOLENOID (A) —XX —
FR/B SOLENOID (A) —XX —
D/C SOLENOID (A) —XX —
HLR/C SOL (A) —XX —
ON OFF SOL (ON-OFF display) —— X LC/B solenoid
TCC SOL MON (A) —— X —
L/P SOL MON (A) —— X —
I/C SOL MON (A) —— X —
FR/B SOL MON (A) —— X —
D/C SOL MON (A) —— X —
HLR/C SOL MON (A) —— X —
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM
MENU
Revision: April 20092010 QX56

TM-36
< FUNCTION DIAGNOSIS >
DIAGNOSIS SYSTEM (TCM)
ONOFF SOL MON (ON-OFF display) ——X LC/B solenoid
P POSI IND (ON-OFF display) —— X —
R POSI IND (ON-OFF display) —— X —
N POSI IND (ON-OFF display) —— X —
D POSI IND (ON-OFF display) —— X —
4TH POSI IND (ON-OFF display) —— X —
3RD POSI IND (ON-OFF display) —— X —
2ND POSI IND (ON-OFF display) —— X —
1ST POSI IND (ON-OFF display) —— X —
MANU MODE IND (ON-OFF display) — —X
Not mounted but displayed.
POWER M LAMP (ON-OFF display) —— X
F-SAFE IND/L (ON-OFF display) —— X —
ATF WARN LAMP (ON-OFF display) — —X —
BACK-UP LAMP (ON-OFF display) —— X —
STARTER RELAY (ON-OFF display) — —X —
RANGE SW3M (ON-OFF display) —— X —
C/V CLB ID1 —— X —
C/V CLB ID2 —— X —
C/V CLB ID3 —— X —
UNIT CLB ID1 —— X —
UNIT CLB ID2 —— X —
UNIT CLB ID3 —— X —
TRGT GR RATIO —— X —
TRGT PRES TCC (kPa) —— X —
TRGT PRES L/P (kPa) —— X —
TRGT PRES I/C (kPa) —— X —
TRGT PRE FR/B (kPa) —— X —
TRGT PRES D/C (kPa) —— X —
TRG PRE HLR/C (kPa) —— X —
SHIFT PATTERN —— X —
DRV CST JUDGE —— X —
START RLY MON —— X —
NEXT GR POSI —— X —
SHIFT MODE —— X —
MANU GR POSI —— X —
VEHICLE SPEED (km/h) —XX Vehicle speed recognized by the TCM.
Voltage (V) —— XDisplays the value measured by the voltage
probe.
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM
MENU
Revision: April 20092010 QX56

DIAGNOSIS SYSTEM (TCM)TM-37
< FUNCTION DIAGNOSIS >
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DTC & SRT CONFIRMATION
DTC Work Support Mode
Diagnosis Procedure without CONSULT-IIIINFOID:0000000005148527
OBD-II SELF-DIAGNOSTIC PROCEDURE (WITH GST)
Refer to EC-72, "Generic Scan Tool (GST) Function".
OBD-II SELF-DIAGNOSTIC PROCEDURE (NO TOOLS)
Refer to EC-55, "Malfunction Indicator Lamp (MIL)".
TCM SELF-DIAGNOSTIC PROCEDURE (NO TOOLS)
Description
When the ignition switch is switched “ON”, the A/T CHECK indicator lamp lights up for 2 seconds. As a method
for locating the suspect circuit, when the self-diagnosti cs start signal is input, the memory for the malfunction
location is output and the A/T CHECK indicator lamp flashes to display the corresponding DTC.
Diagnostic Procedure
1.CHECK A/T CHECK INDICATOR LAMP
1. Start the engine with selector lever in “P” pos ition. Warm engine to normal operating temperature.
2. Turn ignition switch ON and OFF at least twice, then leave it in the OFF position.
3. Wait 10 seconds.
4. Turn ignition switch ON. (Do not start engine.)
Frequency (Hz) —— X
The value measured by the pulse probe is dis-
played.
DUTY-HI (high) (%)
—— X
DUTY-LOW (low) (%) —— X
PLS WIDTH-HI (ms) —— X
PLS WIDTH-LOW (ms) —— X
Monitored item (Unit)
Monitor Item Selection
Remarks
ECU IN-
PUT SIG- NALS MAIN SIG-
NALS SELEC-
TION
FROM
MENU
DTC work support item DescriptionCheck item
1ST GR FNCTN P0731 Following items for “1GR function ratio” be confirmed.
• Self-diagnosis status (whether the diagnosis is being performed
or not)
• Self-diagnosis result (OK or NG)
• Input clutch solenoid valve
• Front brake solenoid valve
• Direct clutch solenoid valve
• High and low reverse clutch solenoid valve
• Each clutch
• Hydraulic co ntrol circuit
valve
2ND GR FNCTN P0732
Following items for “2GR function ratio” be confirmed.
• Self-diagnosis status (whether the diagnosis is being performed
or not)
• Self-diagnosis result (OK or NG)
3RD GR FNCTN P0733 Following items for “3GR function ratio” be confirmed.
• Self-diagnosis status (whether the diagnosis is being performed
or not)
• Self-diagnosis result (OK or NG)
4TH GR FNCTN P0734 Following items for “4GR function ratio” be confirmed.
• Self-diagnosis status (whether the diagnosis is being performed
or not)
• Self-diagnosis result (OK or NG)
5TH GR FNCTN P0735 Following items for “5GR function ratio” be confirmed.
• Self-diagnosis status (whether the diagnosis is being performed
or not)
• Self-diagnosis result (OK or NG)
Revision: April 20092010 QX56