tow INFINITI QX56 2006 Factory Service Manual

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Revision: November 2009 2006 QX56
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

AT-8
PRECAUTIONS
Revision: November 20092006 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 4 , "
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- 1 2 , "
Changing Automatic Transmission Fluid (ATF)" , AT- 1 2 , "Checking Automatic Transmission
Fluid (ATF)" .
SEF289H
SEF217U

A/T FLUIDAT-15
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Revision: November 2009 2006 QX56
6. Hold the hose and can as high as possible and spray Transmission Cooler Cleaner in a continuous
stream into the cooler outlet hose until fluid flows out of the cooler inlet hose for 5 seconds.
7. Insert the tip of an air gun into the end of the cooler outlet hose.
8. Wrap a shop rag around the air gun tip and of the cooler outlet hose.
9. Blow compressed air regulated to 5 - 9 kg/cm
2 (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- 1 4 , "
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.
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AT-30
A/T CONTROL SYSTEM
Revision: November 20092006 QX56
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 signal Shift 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 system
Input 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
Starter relay
Back-up lamp relay
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AT-42
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
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 6
.
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- 4 5 , "
WORK FLOW" ).
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, this function controls the A/T to make 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

AT-60
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
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
ratio
Throttle position Vehicle speed km/h (MPH)
D
1 → D2D2 → D3D3 → D4D4 → D5D5 → D4D4 → D3D3 → D2D2 → D1
2.937 Full 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)
3.357 Full 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
ratio Throttle position Vehicle speed km/h (MPH)
D
1 → D2D2 → D3D3 → D4D4 → D5D5 → D4D4 → D3D3 → D2D2 → D1
2.937 Full 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)
3.357 Full 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 ratio Throttle position Vehicle speed km/h (MPH)
Lock-up “ON ” Lock-up “OFF ”
2.937 Closed throttle
74 - 82 (46 - 51) 71 - 79 (45 - 49)
Half throttle 188 - 196 (117 - 122) 136 - 144 (85 - 90)
3.357 Closed throttle
65 - 73 (41 - 46) 62 - 70 (39 - 44)
Half throttle 168 - 176 (105 - 110) 118 - 126 (74 - 79)
Final
gear
ratioThrottle position Gear position
Vehicle speed km/h (MPH)
Slip lock-up “ON ” Slip lock-up “OFF ”
2.937 Closed throttle 4th
52 - 60 (33 - 38) 49 - 57 (31 - 36)
5th 52 - 60 (33 - 38) 49 - 57 (31 - 36)
3.357 Closed throttle 4th
46 - 54 (29 - 34) 43 - 51 (27 - 32)
5th 46 - 54 (29 - 34) 43 - 51 (27 - 32)

TOW MODE SWITCHAT-173
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Revision: November 2009 2006 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.

AT-174
TOW MODE SWITCH
Revision: November 20092006 QX56
Wiring Diagram — AT — TMSWECS00CK0
BCWA0498E

TOW MODE SWITCHAT-175
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Revision: November 2009 2006 QX56
Diagnostic ProcedureECS00CK1
1. CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to AT- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" .
Is any malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to AT- 9 6 , "DTC U1000 CAN COMMUNICATION LINE" .
NO >> GO TO 2.
2. CHECK POWER SOURCE
1. Turn ignition switch “ON”. (Do not start engine.)
2. Check the voltage between tow mode switch connector M67 ter- minal 1 and ground.
OK or NG
OK >> INSPECTION END
NG >> GO TO 3.
3. CHECK TOW MODE SWITCH
1. Turn ignition switch “OFF”.
2. Disconnect tow mode switch connector.
3. Check continuity between tow mode switch terminals 1 and 2.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace tow mode switch.
4. DETECT MALFUNCTIONING ITEM
Check the following items. If any items are damaged, repair or replace damaged parts.

Harness for short or open between combination meter connector terminal 35 and tow mode switch con-
nector terminal 1.

Harness for short or open between tow mode switch connector terminal 2 and ground.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace damaged parts.
5. CHECK COMBINATION METER
Check the combination meter. Refer to DI-17, "
How to Proceed With Trouble Diagnosis" .
OK or NG
OK >> INSPECTION END
NO >> Repair or replace damaged parts.
Condition To w m o d e
switch Data (Approx.)
When ignition switch is turned to “ON ” ON
0V
OFF Battery voltage
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Condition Continuity
Tow mode switch “ON ” Ye s
Tow mode switch “OFF ” No
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ON-VEHICLE SERVICEAT-235
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Revision: November 2009 2006 QX56
5. Install A/T fluid temperature sensor 2 to bracket.
6. Install A/T fluid temperature sensor 2 (with bracket) in control
valve with TCM. Tighten A/T fluid temperature sensor 2 bolt to
the specified torque. Refer to AT- 2 5 0 , "
Components" .
CAUTION:
Adjust bolt hole of bracket to bolt hole of control valve with
TCM.
7. Install control valve with TCM in transmission case. CAUTION:

Make sure that turbine revolution sensor securely installs
turbine revolution sensor hole.

Hang down revolution sensor harness toward outside so
as not to disturb installation of control valve with TCM.

Adjust A/T assembly harness connector of control valve
with TCM to terminal hole of transmission case.

Assemble it so that manual valve cutout is engaged with
manual plate projection.
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