2006 INFINITI QX56 engine

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DTC Confirmation Procedure ..............................
. 145
Diagnostic Procedure .......................................... . 146
DTC P1762 DIRECT CLUTCH SOLENOID VALVE . 147
Description .......................................................... . 147
CONSULT-II Reference Value ............................. . 147
On Board Diagnosis Logic .................................. . 147
Possible Cause ................................................... . 147
DTC Confirmation Procedure .............................. . 147
Diagnostic Procedure .......................................... . 148
DTC P1764 DIRECT CLUTCH SOLENOID VALVE
FUNCTION ............................................................. . 149
Description .......................................................... . 149
CONSULT-II Reference Value ............................. . 149
On Board Diagnosis Logic .................................. . 149
Possible Cause ................................................... . 149
DTC Confirmation Procedure .............................. . 149
Diagnostic Procedure .......................................... . 150
DTC P1767 HIGH AND LOW REVERSE CLUTCH
SOLENOID VALVE ................................................ . 151
Description .......................................................... . 151
CONSULT-II Reference Value ............................. . 151
On Board Diagnosis Logic .................................. . 151
Possible Cause ................................................... . 151
DTC Confirmation Procedure .............................. . 151
Diagnostic Procedure .......................................... . 152
DTC P1769 HIGH AND LOW REVERSE CLUTCH
SOLENOID VALVE FUNCTION ............................ . 153
Description .......................................................... . 153
CONSULT-II Reference Value ............................. . 153
On Board Diagnosis Logic .................................. . 153
Possible Cause ................................................... . 153
DTC Confirmation Procedure .............................. . 153
Diagnostic Procedure .......................................... . 154
DTC P1772 LOW COAST BRAKE SOLENOID
VALVE .................................................................... . 155
Description .......................................................... . 155
CONSULT-II Reference Value ............................. . 155
On Board Diagnosis Logic .................................. . 155
Possible Cause ................................................... . 155
DTC Confirmation Procedure .............................. . 155
Diagnostic Procedure .......................................... . 156
DTC P1774 LOW COAST BRAKE SOLENOID
VALVE FUNCTION ................................................ . 157
Description .......................................................... . 157
CONSULT-II Reference Value ............................. . 157
On Board Diagnosis Logic .................................. . 157
Possible Cause ................................................... . 157
DTC Confirmation Procedure .............................. . 157
Diagnostic Procedure .......................................... . 158
DTC P1841 ATF PRESSURE SWITCH 1 .............. . 159
Description .......................................................... . 159
CONSULT-II Reference Value ............................. . 159
On Board Diagnosis Logic .................................. . 159
Possible Cause ................................................... . 159
DTC Confirmation Procedure .............................. . 159
Diagnostic Procedure .......................................... . 160
DTC P1843 ATF PRESSURE SWITCH 3 .............. . 161
Description .......................................................... . 161
CONSULT-II Reference Value ............................. . 161On Board Diagnosis Logic ...................................
.161
Possible Cause .................................................... .161
DTC Confirmation Procedure .............................. .161
Diagnostic Procedure .......................................... .162
DTC P1845 ATF PRESSURE SWITCH 5 .............. .163
Description ........................................................... .163
CONSULT-II Reference Value ............................. .163
On Board Diagnosis Logic ................................... .163
Possible Cause .................................................... .163
DTC Confirmation Procedure .............................. .163
Diagnostic Procedure .......................................... .164
DTC P1846 ATF PRESSURE SWITCH 6 .............. .165
Description ........................................................... .165
CONSULT-II Reference Value ............................. .165
On Board Diagnosis Logic ................................... .165
Possible Cause .................................................... .165
DTC Confirmation Procedure .............................. .165
Diagnostic Procedure .......................................... .166
MAIN POWER SUPPLY AND GROUND CIRCUIT .167
Wiring Diagram — AT — MAIN ........................... .167
Diagnostic Procedure .......................................... .168
CLOSED THROTTLE POSITION AND WIDE OPEN
THROTTLE POSITION CIRCUIT ........................... .171
CONSULT-II Reference Value ............................. .171
Diagnostic Procedure .......................................... .171
BRAKE SIGNAL CIRCUIT ..................................... .172
CONSULT-II Reference Value ............................. .172
Diagnostic Procedure .......................................... .172
TOW MODE SWITCH ............................................ .173
Description ........................................................... .173
Wiring Diagram — AT — TMSW ......................... .174
Diagnostic Procedure .......................................... .175
TROUBLE DIAGNOSIS FOR SYMPTOMS ........... .176
Wiring Diagram — AT — NONDTC ..................... .176
A/T CHECK Indicator Lamp Does Not Come On . 179
Engine Cannot Be Started In “P” or “N” Position . .179
In “P” Position, Vehicle Moves When Pushed ..... .180
In “N” Position, Vehicle Moves ............................. .181
Large Shock (“N” to “D” Position) ........................ .182
Vehicle Does Not Creep Backward In “R” Position .186
Vehicle Does Not Creep Forward In “D” Position . 189
Vehicle Cannot Be Started From D
1 .................... .191
A/T Does Not Shift: D
1 → D2 ............................... .194
A/T Does Not Shift: D
2 → D3 ............................... .196
A/T Does Not Shift: D
3 → D4 ............................... .198
A/T Does Not Shift: D
4 → D5 ............................... .201
A/T Does Not Perform Lock-up ........................... .203
A/T Does Not Hold Lock-up Condition ................. .205
Lock-up Is Not Released ..................................... .207
Engine Speed Does Not Return to Idle ............... .208
A/T Does Not Shift: 5th gear → 4th gear ............. .209
A/T Does Not Shift: 4th gear → 3rd gear ............. .212
A/T Does Not Shift: 3rd gear → 2nd gear ............ .213
A/T Does Not Shift: 2nd gear → 1st gear .............215
Vehicle Does Not Decelerate By Engine Brake ... .218
A/T SHIFT LOCK SYSTEM ................................... .221
Description ........................................................... .221
Shift Lock System Electrical Parts Location ........ .221
Wiring Diagram — A/T — SHIFT ......................... .222

INDEX FOR DTCAT-5
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INDEX FOR DTCPFP:00024
Alphabetical Index ECS00CDH
NOTE:
If DTC U1000 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000. Refer to
AT- 9 6 , "
DTC U1000 CAN COMMUNICATION LINE" .
*1: These numbers are prescribed by SAE J2012.
*2: These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL.Items
(CONSULT- II screen terms) DTC
Reference page
OBD- II Except OBD- II
CONSULT- II GST (*1) CONSULT- II only “ A/T”
A/T 1ST E/BRAKING —P1731AT- 1 3 7
ATF PRES SW 1/CIRC —P1841AT- 1 5 9
ATF PRES SW 3/CIRC —P1843AT- 1 6 1
ATF PRES SW 5/CIRC —P1845AT- 1 6 3
ATF PRES SW 6/CIRC —P1846AT- 1 6 5
A/T INTERLOCK P1730P1730AT- 1 3 4
A/T TCC S/V FNCTN P0744 P0744 AT- 1 2 0
ATF TEMP SEN/CIRC P0710P1710AT- 1 2 7
CAN COMM CIRCUIT U1000U1000AT- 9 6
D/C SOLENOID/CIRC P1762P1762AT- 1 4 7
D/C SOLENOID FNCTN P1764 (*2 )P1764 AT- 1 4 9
ENGINE SPEED SIG —P0725AT- 11 6
FR/B SOLENOID/CIRC P1757P1757AT- 1 4 3
FR/B SOLENOID FNCT P1759 P1759 AT- 1 4 5
HLR/C SOL/CIRC P1767P1767AT- 1 5 1
HLR/C SOL FNCTN P1769 (*2 ) P1769 AT- 1 5 3
I/C SOLENOID/CIRC P1752P1752AT- 1 3 9
I/C SOLENOID FNCTN P1754 (*2 ) P1754 AT- 1 4 1
L/PRESS SOL/CIRC P0745P0745AT- 1 2 2
LC/B SOLENOID/CIRC P1772P1772AT- 1 5 5
LC/B SOLENOID FNCT P1774 P1774 AT- 1 5 7
PNP SW/CIRC P0705P0705AT- 1 0 5
STARTER RELAY/CIRC —P0615AT- 1 0 0
TCC SOLENOID/CIRC P0740P0740AT- 11 8
TCM P0700P0700AT- 1 0 4
TP SEN/CIRC A/T —P1705AT- 1 2 4
TURBINE REV S/CIRC P0717P0717AT- 1 0 9
VEH SPD SE/CIR·MTR —P1721AT- 1 3 2
VEH SPD SEN/CIR AT P0720P0720AT- 111

AT-6
INDEX FOR DTC
Revision: November 20092006 QX56
DTC No. Index ECS00CDI
NOTE:
If DTC U1000 is displayed with other DTC, first perform the trouble diagnosis for DTC U1000. Refer to
AT- 9 6 , "
DTC U1000 CAN COMMUNICATION LINE" .
*1: These numbers are prescribed by SAE J2012.
*2: These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL.DTC
Items
(CONSULT- II screen terms) Reference page
OBD- II
Except OBD- II
CONSULT- II GST (*1) C O N S U LT- I I
only “A/T ”
— P0615 STARTER RELAY/CIRC AT- 1 0 0
P0700P0700 TCM AT- 1 0 4
P0705P0705 PNP SW/CIRC AT- 1 0 5
P0710P1710 ATF TEMP SEN/CIRC AT- 1 2 7
P0717P0717 TURBINE REV S/CIRC AT- 1 0 9
P0720P0720 VEH SPD SEN/CIR AT AT- 111
—P0725 ENGINE SPEED SIG AT- 11 6
P0740P0740 TCC SOLENOID/CIRC AT- 11 8
P0744 P0744 A/T TCC S/V FNCTN AT- 1 2 0
P0745P0745 L/PRESS SOL/CIRC AT- 1 2 2
—P1705 TP SEN/CIRC A/T AT- 1 2 4
—P1721 VEH SPD SE/CIR· MTR AT- 1 3 2
P1730P1730 A/T INTERLOCK AT- 1 3 4
— P1731 A/T 1ST E/BRAKING AT- 1 3 7
P1752P1752 I/C SOLENOID/CIRC AT- 1 3 9
P1754 (*2 ) P1754 I/C SOLENOID FNCTN AT- 1 4 1
P1757P1757 FR/B SOLENOID/CIRC AT- 1 4 3
P1759 (*2 ) P1759 FR/B SOLENOID FNCT AT- 1 4 5
P1762P1762 D/C SOLENOID/CIRC AT- 1 4 7
P1764 (*2 )P1764 D/C SOLENOID FNCTN AT- 1 4 9
P1767P1767 HLR/C SOL/CIRC AT- 1 5 1
P1769 P1769 HLR/C SOL FNCTN AT- 1 5 3
P1772P1772 LC/B SOLENOID/CIRC AT- 1 5 5
P1774 P1774 LC/B SOLENOID FNCT AT- 1 5 7
—P1841 ATF PRES SW 1/CIRC AT- 1 5 9
—P1843 ATF PRES SW 3/CIRC AT- 1 6 1
—P1845 ATF PRES SW 5/CIRC AT- 1 6 3
—P1846 ATF PRES SW 6/CIRC AT- 1 6 5
U1000U1000 CAN COMM CIRCUIT AT- 9 6

PRECAUTIONSAT-7
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Revision: November 2009 2006 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
ECS00CDJ
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER ”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WARNING:

To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.

Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.

Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
Precautions for On Board Diagnostic (OBD) System of A/T and EngineECS00CDK
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:

Be sure to turn the ignition switch “OFF” and disconnect the negative battery cable before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves,
etc. Will cause the MIL to light up.

Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MIL to light up due to an open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)

Be sure to route and secure the harnesses properly after work. Interference of the harness with a
bracket, etc. May cause the MIL to light up due to a short circuit.

Be sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to a malfunction of the EGR system or fuel injection system, etc.

Be sure to erase the unnecessary malfunction information (repairs completed) from the TCM and
ECM before returning the vehicle to the customer.

AT-12
A/T FLUID
Revision: November 20092006 QX56
A/T FLUIDPFP:KLE40
Changing Automatic Transmission Fluid (ATF)ECS00EPX
1. Drive the vehicle to warm up the ATF to 80° C (176 ° F).
2. Stop the engine.
3. Remove the ATF level gauge bolt.
4. Drain the ATF from the drain plug hole and then install the drain plug with a new gasket. Refill the transmission with new ATF.
Always refill with the same volume as the drained ATF. Use the
ATF level gauge to check the ATF level as shown. Add ATF as
necessary.

To flush out the old ATF from the coolers, pour new ATF into the charging pipe with the engine idling
and at the same time drain the old ATF from the auxiliary transmission oil cooler hose return line.

When the color of the ATF coming out of the auxiliary transmission oil cooler hose return line is about
the same as the color of the new ATF, flushing out the old ATF is complete. The amount of new trans-
mission ATF used for flushing should be 30% to 50% of the specified capacity.
CAUTION:

Use only the specified ATF. Do not mix with other fluids.

Using an ATF other than the specified ATF will cause deterioration in driveability and automatic
transmission durability, and may damage the automatic transmission, which is not covered by
the warranty.

When filling the transmission with ATF, do not spill the ATF on any heat generating parts such
as the exhaust manifold.

Do not reuse the drain plug gasket.
5. Install the ATF level gauge in the ATF charging pipe and tighten the level gauge bolt to specification.
6. Drive the vehicle to warm up the ATF to 80 ° C (176 ° F).
7. Check the ATF level and condition. Refer to AT- 1 2 , "
Checking Automatic Transmission Fluid (ATF)" . If the
ATF is still dirty, repeat steps 2 through 5.
Checking Automatic Transmission Fluid (ATF)ECS00EPY
1. Remove the ATF level gauge bolt.
2. Before driving, the ATF level can be checked at ATF tempera- tures of 30 ° to 50 °C (86 ° to 122 °F) using the “COLD” range on
the ATF level gauge as follows:
a. Park the vehicle on a level surface and set the parking brake.
b. Start the engine and move the selector lever through each gear position. Shift the selector lever into the “P” position.
c. Check the ATF level with the engine idling.
d. Remove the ATF level gauge and wipe it clean with a lint-free paper.
CAUTION:
When wiping the ATF from the ATF level gauge, always use
a lint-free paper, not a cloth.Drain plug : Refer to
AT- 2 5 0 , "
Components" .
WLIA0014E
ATF type and capacity : Refer to MA-11, "Fluids and Lubricants" .
Drain plug : Refer to AT- 2 5 0 , "
Components" .
Level gauge bolt : Refer to AT- 2 5 0 , "
Components" .
WLIA0014E

A/T FLUIDAT-13
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Revision: November 2009 2006 QX56
e. Re-insert the ATF level gauge into the charging pipe until the
cap contacts the top of the charging pipe as shown.
CAUTION:
To check ATF level, insert the ATF level gauge until the cap
contacts the top of the charging pipe, with the gauge
reversed from the normal inserted position.
f. Remove the ATF level gauge and note the ATF level. If the ATF level is at low side of range, add ATF to the transmission
through the charging pipe.
CAUTION:
Do not overfill the transmission with ATF.
g. Install the ATF level gauge and the ATF level gauge bolt.
3. Warm up the engine.
4. Check for any ATF leaks.
5. Drive the vehicle to increase the ATF temperature to 80 ° C (176 ° F).
6. Allow the ATF temperature to fall to approximately 65 °C (149 °F). Use the CONSULT-II to monitor the ATF
temperature as follows:
NOTE:
ATF level will be greatly affected by temperature as shown. Therefore monitor the ATF temperature data
using the CONSULT-II.
a. Connect CONSULT-II to data link connector.
b. Select “MAIN SIGNALS ” in “DATA MONITOR ” mode for “A/T” with CONSULT-II.
c. Read out the value of “ATF TEMP 1”.
7. Re-check the ATF level at ATF temperatures of approximately 65°C (149 °F) using the “HOT ” range on the ATF level gauge as
shown.
CAUTION:

When wiping the ATF from the ATF level gauge, always
use lint-free paper, not a cloth. ATF level gauge bolt : Refer to AT- 2 5 0 , "
Components" .
SCIA1684E
SLIA0016E
WLIA0014E

AT-22
A/T CONTROL SYSTEM
Revision: November 20092006 QX56
“D”, “4”, “3”, “2” Positions 1st Gear

The forward brake and the forward one-way clutch regulate reverse rotation of the mid sun gear.

The 1st one-way clutch regulates reverse rotation of the rear sun gear.

The 3rd one-way clutch regulates reverse rotation of the front sun gear.

During deceleration, the mid sun gear turns forward, so the forward one-way clutch idles and the engine
brake is not activated.
1. Front brake2. Input clutch 3. Direct clutch
4. High and low reverse clutch 5. Reverse brake 6. Forward brake
7. Low coast brake 8. 1st one-way clutch 9. Forward one-way clutch
10. 3rd one-way clutch 11. Front sun gear 12. Input shaft
13. Mid internal gear 14. Front internal gear 15. Rear carrier
16. Rear sun gear 17. Mid sun gear 18. Front carrier
19. Mid carrier 20. Rear internal gear 21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1512E

A/T CONTROL SYSTEMAT-23
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“1 ” Position 1st Gear

The front brake fastens the front sun gear.

The forward brake and the forward one-way clutch regulate reverse rotation of the mid sun gear.

High and low reverse clutch connects the rear sun gear and the mid sun gear.

The low coast brake fastens the mid sun gear.

During deceleration, the low coast brake regulates forward rotation of the mid sun gear and the engine
brake functions.
1. Front brake2. Input clutch3. Direct clutch
4. High and low reverse clutch 5. Reverse brake 6. Forward brake
7. Low coast brake 8. 1st one-way clutch9. Forward one-way clutch
10. 3rd one-way clutch 11. Front sun gear12. Input shaft
13. Mid internal gear 14. Front internal gear15. Rear carrier
16. Rear sun gear 17. Mid sun gear18. Front carrier
19. Mid carrier 20. Rear internal gear21. Output shaft
22. Parking gear 23. Parking pawl
SCIA1513E