2005 INFINITI QX4 tow

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Revision: October 20052005 QX56 DTC Confirmation Procedure ............................... 142
Diagnostic Procedure ........................................... 143
DTC P1757 FRONT BRAKE SOLENOID VALVE .. 144
Description ........................................................... 144
CONSULT-II Reference Value .............................. 144
On Board Diagnosis Logic ................................... 144
Possible Cause .................................................... 144
DTC Confirmation Procedure ............................... 144
Diagnostic Procedure ........................................... 145
DTC P1759 FRONT BRAKE SOLENOID VALVE
FUNCTION .............................................................. 146
Description ........................................................... 146
CONSULT-II Reference Value .............................. 146
On Board Diagnosis Logic ................................... 146
Possible Cause .................................................... 146
DTC Confirmation Procedure ............................... 146
Diagnostic Procedure ........................................... 147
DTC P1762 DIRECT CLUTCH SOLENOID VALVE . 148
Description ........................................................... 148
CONSULT-II Reference Value .............................. 148
On Board Diagnosis Logic ................................... 148
Possible Cause .................................................... 148
DTC Confirmation Procedure ............................... 148
Diagnostic Procedure ........................................... 149
DTC P1764 DIRECT CLUTCH SOLENOID VALVE
FUNCTION .............................................................. 150
Description ........................................................... 150
CONSULT-II Reference Value .............................. 150
On Board Diagnosis Logic ................................... 150
Possible Cause .................................................... 150
DTC Confirmation Procedure ............................... 150
Diagnostic Procedure ........................................... 151
DTC P1767 HIGH AND LOW REVERSE CLUTCH
SOLENOID VALVE ................................................. 152
Description ........................................................... 152
CONSULT-II Reference Value .............................. 152
On Board Diagnosis Logic ................................... 152
Possible Cause .................................................... 152
DTC Confirmation Procedure ............................... 152
Diagnostic Procedure ........................................... 153
DTC P1769 HIGH AND LOW REVERSE CLUTCH
SOLENOID VALVE FUNCTION ............................. 154
Description ........................................................... 154
CONSULT-II Reference Value .............................. 154
On Board Diagnosis Logic ................................... 154
Possible Cause .................................................... 154
DTC Confirmation Procedure ............................... 154
Diagnostic Procedure ........................................... 155
DTC P1772 LOW COAST BRAKE SOLENOID
VALVE ..................................................................... 156
Description ........................................................... 156
CONSULT-II Reference Value .............................. 156
On Board Diagnosis Logic ................................... 156
Possible Cause .................................................... 156
DTC Confirmation Procedure ............................... 156
Diagnostic Procedure ........................................... 157
DTC P1774 LOW COAST BRAKE SOLENOID
VALVE FUNCTION ................................................. 158
Description ........................................................... 158CONSULT-II Reference Value ..............................158
On Board Diagnosis Logic ....................................158
Possible Cause .....................................................158
DTC Confirmation Procedure ...............................158
Diagnostic Procedure ...........................................159
DTC P1841 ATF PRESSURE SWITCH 1 ...............160
Description ............................................................160
CONSULT-II Reference Value ..............................160
On Board Diagnosis Logic ....................................160
Possible Cause .....................................................160
DTC Confirmation Procedure ...............................160
Diagnostic Procedure ...........................................161
DTC P1843 ATF PRESSURE SWITCH 3 ...............162
Description ............................................................162
CONSULT-II Reference Value ..............................162
On Board Diagnosis Logic ....................................162
Possible Cause .....................................................162
DTC Confirmation Procedure ...............................162
Diagnostic Procedure ...........................................163
DTC P1845 ATF PRESSURE SWITCH 5 ...............164
Description ............................................................164
CONSULT-II Reference Value ..............................164
On Board Diagnosis Logic ....................................164
Possible Cause .....................................................164
DTC Confirmation Procedure ...............................164
Diagnostic Procedure ...........................................165
DTC P1846 ATF PRESSURE SWITCH 6 ...............166
Description ............................................................166
CONSULT-II Reference Value ..............................166
On Board Diagnosis Logic ....................................166
Possible Cause .....................................................166
DTC Confirmation Procedure ...............................166
Diagnostic Procedure ...........................................167
MAIN POWER SUPPLY AND GROUND CIRCUIT .168
Wiring Diagram — AT — MAIN ............................168
Diagnostic Procedure ...........................................169
CLOSED THROTTLE POSITION AND WIDE OPEN
THROTTLE POSITION CIRCUIT ............................172
CONSULT-II Reference Value ..............................172
Diagnostic Procedure ...........................................172
BRAKE SIGNAL CIRCUIT ......................................173
CONSULT-II Reference Value ..............................173
Diagnostic Procedure ...........................................173
TOW MODE SWITCH .............................................174
Description ............................................................174
Wiring Diagram — AT — TMSW ..........................175
Diagnostic Procedure ...........................................176
TROUBLE DIAGNOSIS FOR SYMPTOMS ............177
Wiring Diagram — AT — NONDTC ......................177
A/T CHECK Indicator Lamp Does Not Come On . 180
Engine Cannot Be Started In “P” or “N” Position ..180
In “P” Position, Vehicle Moves When Pushed ......181
In “N” Position, Vehicle Moves ..............................182
Large Shock (“N” to “D” Position) .........................183
Vehicle Does Not Creep Backward In “R” Position .187
Vehicle Does Not Creep Forward In “D” Position . 190
Vehicle Cannot Be Started From D
1 .....................192
A/T Does Not Shift: D
1 → D2 ................................195
A/T Does Not Shift: D
2 → D3 ................................197

AT-8
PRECAUTIONS
Revision: October 20052005 QX56
Precautions ECS00CDL

Before connecting or disconnecting the A/T assembly har-
ness connector, turn ignition switch “OFF” and disconnect
negative battery cable. Because battery voltage is applied
to TCM even if ignition switch is turned “OFF”.

After performing each TROUBLE DIAGNOSIS, perform
“DTC (Diagnostic Trouble Code) CONFIRMATION PROCE-
DURE”.
If the repair is completed the DTC should not be displayed
in the “DTC CONFIRMATION PROCEDURE”.

Always use the specified brand of ATF. Refer to MA-11, "RECOMMENDED FLUIDS AND LUBRICANTS" .

Use paper rags not cloth rags during work.

After replacing the ATF, dispose of the waste oil using the methods prescribed by law, ordinance, etc.

Before proceeding with disassembly, thoroughly clean the outside of the transmission. It is important to
prevent the internal parts from becoming contaminated by dirt or other foreign matter.

Disassembly should be done in a clean work area.

Use lint-free cloth or towels for wiping parts clean. Common shop rags can leave fibers that could interfere
with the operation of the transmission.

Place disassembled parts in order for easier and proper assembly.

All parts should be carefully cleaned with a general purpose, non-flammable solvent before inspection or
reassembly.

Gaskets, seals and O-rings should be replaced any time the transmission is disassembled.

It is very important to perform functional tests whenever they are indicated.

The valve body contains precision parts and requires extreme care when parts are removed and serviced.
Place disassembled valve body parts in order for easier and proper assembly. Care will also prevent
springs and small parts from becoming scattered or lost.

Properly installed valves, sleeves, plugs, etc. will slide along bores in valve body under their own weight.

Before assembly, apply a coat of recommended ATF to all parts. Apply petroleum jelly to protect O-rings
and seals, or hold bearings and washers in place during assembly. Do not use grease.

Extreme care should be taken to avoid damage to O-rings, seals and gaskets when assembling.

Clean or replace ATF cooler if excessive foreign material is found in oil pan or clogging strainer. Refer to
AT- 1 3 , "
A/T Fluid Cooler Cleaning" .

After overhaul, refill the transmission with new ATF.

When the A/T drain plug is removed, only some of the fluid is drained. Old A/T fluid will remain in torque
converter and ATF cooling system.
Always follow the procedures under “Changing A/T Fluid” in the AT section when changing A/T fluid. Refer
to AT-13, "
Changing A/T Fluid" , AT-13, "Checking A/T Fluid" .
SEF 2 89 H
SEF 2 17 U

AT-14
A/T FLUID
Revision: October 20052005 QX56
9. Blow compressed air regulated to 5 - 9 kg/cm2 (70 - 130 psi) through the cooler outlet hose for 10 sec-
onds to force out any remaining fluid.
10. Repeat steps 5 through 9 three additional times.
11. Position an oil pan under the banjo bolts that connect the fluid cooler steel lines to the transmission.
12. Remove the banjo bolts.
13. Flush each steel line from the cooler side back toward the transmission by spraying Transmission Cooler
Cleaner in a continuous stream for 5 seconds.
14. Blow compressed air regulated to 5 - 9 kg/cm
2 (70 - 130 psi) through each steel line from the cooler side
back toward the transmission for 10 seconds to force out any remaining fluid.
15. Ensure all debris is removed from the steel cooler lines.
16. Ensure all debris is removed from the banjo bolts and fittings.
17. Perform AT-13, "
A/T FLUID COOLER CLEANING PROCEDURE" .
A/T FLUID COOLER DIAGNOSIS PROCEDURE
NOTE:
Insufficient cleaning of the cooler inlet hose exterior may lead to inaccurate debris identification.
1. Position an oil pan under the automatic transmission's inlet and outlet cooler hoses.
2. Clean the exterior and tip of the cooler inlet hose.
3. Insert the extension adapter hose of a can of Transmission
Cooler Cleaner (Nissan P/N 999MP-AM006) into the cooler out-
let hose.
CAUTION:

Wear safety glasses and rubber gloves when spraying
the Transmission Cooler Cleaner.

Spray cooler cleaner only with adequate ventilation.

Avoid contact with eyes and skin.

Do not breath vapors or spray mist.
4. Hold the hose and can as high as possible and spray Transmis-
sion Cooler Cleaner in a continuous stream into the cooler outlet
hose until fluid flows out of the cooler inlet hose for 5 seconds.
5. Tie a common white, basket-type coffee filter to the end of the
cooler inlet hose.
6. Insert the tip of an air gun into the end of the cooler outlet hose.
7. Wrap a shop rag around the air gun tip and end of cooler outlet
hose.
8. Blow compressed air regulated to 5 - 9 kg/cm
2 (70 - 130 psi)
through the cooler outlet hose to force any remaining A/T fluid
into the coffee filter.
9. Remove the coffee filter from the end of the cooler inlet hose.
10. Perform AT - 1 5 , "
A/T FLUID COOLER INSPECTION PROCE-
DURE" .
SCIA3831E
SCIA3833E
SCIA3834E

A/T CONTROL SYSTEM
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TCM FunctionECS00CDW
The function of the TCM is to:

Receive input signals sent from various switches and sensors.

Determine required line pressure, shifting point, lock-up operation, and engine brake operation.

Send required output signals to the respective solenoids.
CONTROL SYSTEM OUTLINE
The automatic transmission senses vehicle operating conditions through various sensors or signals. It always
controls the optimum shift position and reduces shifting and lock-up shocks.
CONTROL SYSTEM DIAGRAM
SENSORS (or SIGNALS)


TCM


ACTUATORS
PNP switch
Accelerator pedal position sensor
Closed throttle position signal
Wide open throttle position signal
Engine speed signal
A/T fluid temperature sensor
Revolution sensor
Vehicle speed signal
Stop lamp switch signal
Turbine revolution sensor
1st position switch signal
4th position switch signal
ATF pressure switch signal
Tow mode switch signalShift control
Line pressure control
Lock-up control
Engine brake control
Timing control
Fail-safe control
Self-diagnosis
CONSULT-II communication line
Duet-EA control
CAN systemInput clutch solenoid valve
Direct clutch solenoid valve
Front brake solenoid valve
High and low reverse clutch
solenoid valve
Low coast brake solenoid valve
Torque converter clutch solenoid
valve
Line pressure solenoid valve
A/T CHECK indicator lamp
Sta rte r re lay
Back-up lamp relay
SCIA5624E

TROUBLE DIAGNOSIS
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TROUBLE DIAGNOSISPFP:00004
DTC Inspection Priority ChartECS00CE9
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC U1000 is displayed with other DTCs, first perform the trouble diagnosis for DTC U1000. Refer to
AT-9 5
.
Fail-SafeECS00CEA
The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is an error in a
main electronic control input/output signal circuit. In fail-safe mode the transmission is fixed in 2nd, 4th or 5th
(depending on the breakdown position), so the customer should feel “slipping” or “poor acceleration”.
Even when the electronic circuits are normal, under special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping the tire rotation), the transmission can go into fail-safe
mode. If this happens, switch “OFF” the ignition switch for 10 seconds, then switch it “ON” again to return to
the normal shift pattern. Therefore, the customer's vehicle has returned to normal, so handle according to the
“diagnostics flow” (Refer to AT-44, "
WORK FLOW" ).
FAI L-S AFE FUN CT ION
If any malfunction occurs in a sensor or solenoid, this function controls the A/T to mark driving possible.
Vehicle Speed Sensor

Signals are input from two systems - from vehicle speed sensor A/T (revolution sensor) installed on the
transmission and from combination meter so normal driving is possible even if there is a malfunction in
one of the systems. And if vehicle speed sensor A/T (revolution sensor) has unusual cases, 5th gear is
prohibited.
Accelerator Pedal Position Sensor

If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM accord-
ing to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow
systems, the engine speed is fixed by ECM to a pre-determined engine speed to make driving possible.
Throttle Position Sensor

If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM accord-
ing to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow
systems, the accelerator opening angle is controlled by the idle signal sent from the ECM which is based
on input indicating either idle condition or off-idle condition (pre-determined accelerator opening) in order
to make driving possible.
PNP Switch

In the unlikely event that a malfunction signal enters the TCM, the position indicator is switched “OFF”, the
starter relay is switched “OFF” (starter starting is disabled), the back-up lamp relay switched “OFF” (back-
up lamp is OFF) and the position is fixed to the “D” range to make driving possible.
Starter Relay

The starter relay is switched “OFF”. (Starter starting is disabled.)
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above

TROUBLE DIAGNOSIS
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Vehicle Speed When Shifting GearsECS00CEK
NORMAL MODE

At half throttle, the accelerator opening is 4/8 of the full opening.
TOW MODE

At half throttle, the accelerator opening is 4/8 of the full opening.
Vehicle Speed When Performing and Releasing Complete Lock-up ECS00CEL

At closed throttle, the accelerator opening is less than 1/8 condition.

At half throttle, the accelerator opening is 4/8 of the full opening.
Vehicle Speed When Performing and Releasing Slip Lock-upECS00CEM

At closed throttle, the accelerator opening is less than 1/8 condition. Final
gear
ratioThrottle positionVehicle speed km/h (MPH)
D
1 →D2D2 →D3D3 →D4D4 →D5D5 →D4D4 →D3D3 →D2D2 →D1
2.937Full throttle 70 - 74
(44 - 46)112 - 120
(70 - 75)176 - 186
(110 - 116)249 - 259
(155 - 161)245 - 255
(152 - 159)166 - 176
(103 - 110)100 - 108
(62 - 67)43 - 47
(27 - 30)
Half throttle 46 - 50
(28 - 31)74 - 82
(46 - 51)103 - 113
(64 - 70)135 - 145
(84 - 90)109 - 119
(68 - 74)69 - 79
(43 - 49)44 - 52
(27 - 32)11 - 1 5
(7 - 10)
3.357Full throttle 61 - 65
(38 - 41)97 - 105
(61 - 66)153 - 163
(95 - 102)236 - 246
(147 - 153)232 - 242
(144 - 151)143 - 153
(89 - 95)87 - 95
(54 - 59)43 - 47
(27 - 29)
Half throttle 41 - 45
(26 - 28)66 - 74
(41 - 46)89 - 99
(56 - 62)117 - 127
(73 - 79)95 - 105
(59 - 65)59 - 69
(37 - 43)38 - 46
(24 - 29)11 - 1 5
(7 - 10)
Final
gear
ratioThrottle positionVehicle speed km/h (MPH)
D
1 →D2D2 →D3D3 →D4D4 →D5D5 →D4D4 →D3D3 →D2D2 →D1
2.937Full throttle 70 - 74
(44 - 46)112 - 120
(70 - 75)176 - 186
(110 - 116)249 - 259
(155 - 161)245 - 255
(152 - 159)166 - 176
(103 - 110)100 - 108
(62 - 67)43 - 47
(27 - 30)
Half throttle 50 - 54
(31 - 34)81 - 89
(50 - 55)113 - 123
(70 - 76)135 - 145
(84 - 90)109 - 119
(68 - 74)68 - 78
(42 - 48)44 - 52
(27 - 32)11 - 1 5
(7 - 10)
3.357Full throttle 61 - 65
(38 - 41)97 - 105
(61 - 66)153 - 163
(95 - 102)236 - 246
(147 - 153)232 - 242
(144 - 151)143 - 153
(89 - 95)87 - 95
(54 - 59)43 - 47
(27 - 29)
Half throttle 43 - 47
(27 - 29)72 - 80
(45 - 50)98 - 108
(61 - 67)117 - 127
(73 - 79)95 - 105
(59 - 65)59 - 69
(37 - 43)37 - 45
(23 - 28)11 - 1 5
(7 - 10)
Final
gear
ratioThrottle positionVehicle speed km/h (MPH)
Lock-up “ON” Lock-up “OFF”
2.937Closed throttle 74 - 82 (46 - 51) 71 - 79 (45 - 49)
Half throttle 188 - 196 (117 - 122) 136 - 144 (85 - 90)
3.357Closed throttle 65 - 73 (41 - 46) 62 - 70 (39 - 44)
Half throttle 168 - 176 (105 - 110) 118 - 126 (74 - 79)
Final
gear
ratioThrottle position Gear positionVehicle speed km/h (MPH)
Slip lock-up “ON” Slip lock-up “OFF”
2.937 Closed throttle4th 52 - 60 (33 - 38) 49 - 57 (31 - 36)
5th 52 - 60 (33 - 38) 49 - 57 (31 - 36)
3.357 Closed throttle4th 46 - 54 (29 - 34) 43 - 51 (27 - 32)
5th 46 - 54 (29 - 34) 43 - 51 (27 - 32)

AT-174
TOW MODE SWITCH
Revision: October 20052005 QX56
TOW MODE SWITCHPFP:25129
DescriptionECS00CJZ
When tow mode switch is “ON”, tow mode switch signals are sent to TCM from combination meter by CAN
communication line.Then it`s a tow mode condition.

TOW MODE SWITCH
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Revision: October 20052005 QX56
Wiring Diagram — AT — TMSWECS00CK0
BCWA0413E