2004 INFINITI QX56 check engine

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Revision: August 20072004 QX56 On Board Diagnosis Logic ................................... 151
Possible Cause .................................................... 151
DTC Confirmation Procedure ............................... 151
Diagnostic Procedure ........................................... 152
DTC P1759 FRONT BRAKE 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 P1762 DIRECT CLUTCH SOLENOID VALVE . 157
Description ........................................................... 157
CONSULT-II Reference Value .............................. 157
On Board Diagnosis Logic ................................... 157
Possible Cause .................................................... 157
DTC Confirmation Procedure ............................... 157
Diagnostic Procedure ........................................... 158
DTC P1764 DIRECT CLUTCH SOLENOID VALVE
FUNCTION .............................................................. 160
Description ........................................................... 160
CONSULT-II Reference Value .............................. 160
On Board Diagnosis Logic ................................... 160
Possible Cause .................................................... 160
DTC Confirmation Procedure ............................... 160
Diagnostic Procedure ........................................... 161
DTC P1767 HIGH AND LOW REVERSE CLUTCH
SOLENOID VALVE ................................................. 163
Description ........................................................... 163
CONSULT-II Reference Value .............................. 163
On Board Diagnosis Logic ................................... 163
Possible Cause .................................................... 163
DTC Confirmation Procedure ............................... 163
Diagnostic Procedure ........................................... 164
DTC P1769 HIGH AND LOW REVERSE CLUTCH
SOLENOID VALVE FUNCTION ............................. 166
Description ........................................................... 166
CONSULT-II Reference Value .............................. 166
On Board Diagnosis Logic ................................... 166
Possible Cause .................................................... 166
DTC Confirmation Procedure ............................... 166
Diagnostic Procedure ........................................... 167
DTC P1772 LOW COAST BRAKE SOLENOID
VALVE ..................................................................... 169
Description ........................................................... 169
CONSULT-II Reference Value .............................. 169
On Board Diagnosis Logic ................................... 169
Possible Cause .................................................... 169
DTC Confirmation Procedure ............................... 169
Diagnostic Procedure ........................................... 170
DTC P1774 LOW COAST BRAKE SOLENOID
VALVE FUNCTION ................................................. 172
Description ........................................................... 172
CONSULT-II Reference Value .............................. 172
On Board Diagnosis Logic ................................... 172
Possible Cause .................................................... 172
DTC Confirmation Procedure ............................... 172
Diagnostic Procedure ........................................... 173DTC P1841 ATF PRESSURE SWITCH 1 ...............175
Description ............................................................175
CONSULT-II Reference Value ..............................175
On Board Diagnosis Logic ....................................175
Possible Cause .....................................................175
DTC Confirmation Procedure ...............................175
Diagnostic Procedure ...........................................176
DTC P1843 ATF PRESSURE SWITCH 3 ...............178
Description ............................................................178
CONSULT-II Reference Value ..............................178
On Board Diagnosis Logic ....................................178
Possible Cause .....................................................178
DTC Confirmation Procedure ...............................178
Diagnostic Procedure ...........................................179
DTC P1845 ATF PRESSURE SWITCH 5 ...............181
Description ............................................................181
CONSULT-II Reference Value ..............................181
On Board Diagnosis Logic ....................................181
Possible Cause .....................................................181
DTC Confirmation Procedure ...............................181
Diagnostic Procedure ...........................................182
DTC P1846 ATF PRESSURE SWITCH 6 ...............184
Description ............................................................184
CONSULT-II Reference Value ..............................184
On Board Diagnosis Logic ....................................184
Possible Cause .....................................................184
DTC Confirmation Procedure ...............................184
Diagnostic Procedure ...........................................185
CLOSED THROTTLE POSITION AND WIDE OPEN
THROTTLE POSITION CIRCUIT ............................187
CONSULT-II Reference Value ..............................187
Diagnostic Procedure ...........................................187
BRAKE SIGNAL CIRCUIT ......................................188
CONSULT-II Reference Value ..............................188
Diagnostic Procedure ...........................................188
TOW MODE SWITCH .............................................189
Description ............................................................189
Diagnostic Procedure ...........................................189
TROUBLE DIAGNOSIS FOR SYMPTOMS ............191
AT CHECK Indicator Lamp Does Not Come On ..191
Engine Cannot Be Started In “P” or “N” Position ..192
In “P” Position, Vehicle Moves When Pushed ......193
In “N” Position, Vehicle Moves ..............................194
Large Shock (“N” to “D” Position) .........................195
Vehicle Does Not Creep Backward In “R” Position .198
Vehicle Does Not Creep Forward In “D” Position . 201
Vehicle Cannot Be Started From D
1 .....................203
A/T Does Not Shift: D
1 → D2 ................................206
A/T Does Not Shift: D
2 → D3 ................................208
A/T Does Not Shift: D
3 → D4 ................................210
A/T Does Not Shift: D
4 → D5 ................................213
A/T Does Not Perform Lock-up ............................215
A/T Does Not Hold Lock-up Condition ..................217
Lock-up Is Not Released ......................................219
Engine Speed Does Not Return to Idle ................220
A/T Does Not Shift: 5th gear → 4th gear ..............221
A/T Does Not Shift: 4th gear → 3rd gear ..............224
A/T Does Not Shift: 3rd gear → 2nd gear .............225

AT-4Revision: August 20072004 QX56 A/T Does Not Shift: 2nd gear → 1st gear .............227
Vehicle Does Not Decelerate By Engine Brake ....230
SHIFT CONTROL SYSTEM ....................................233
Control Device Removal and Installation ..............233
Adjustment of A/T Position ...................................234
Checking of A/T Position ......................................234
A/T SHIFT LOCK SYSTEM .....................................236
Description ............................................................236
Shift Lock System Electrical Parts Location .........236
Wiring Diagram — A/T — SHIFT ..........................237
Shift Lock Control Unit Reference Values .............238
Component Inspection ..........................................239
ON-VEHICLE SERVICE ..........................................241
Control Valve With TCM and A/T Fluid Temperature
Sensor 2 ...............................................................241
Rear Oil Seal ........................................................252
AIR BREATHER HOSE ...........................................253
Removal and Installation ......................................253
TRANSMISSION ASSEMBLY ................................255
Removal and Installation (4x2) .............................255
Removal and Installation (4x4) .............................258
OVERHAUL .............................................................261
Components .........................................................261
Oil Channel ...........................................................269
Locations of Adjusting Shims, Needle Bearings,
Thrust Washers and Snap Rings ..........................271
DISASSEMBLY .......................................................273
Disassembly .........................................................273REPAIR FOR COMPONENT PARTS ...................... 290
Oil Pump ............................................................... 290
Front Sun Gear, 3rd One-Way Clutch ................... 292
Front Carrier, Input Clutch, Rear Internal Gear ..... 295
Mid Sun Gear, Rear Sun Gear, High and Low
Reverse Clutch Hub .............................................. 300
High and Low Reverse Clutch .............................. 305
Direct Clutch ......................................................... 307
ASSEMBLY ............................................................. 309
Assembly (1) ......................................................... 309
Adjustment ............................................................ 322
Assembly (2) ......................................................... 324
SERVICE DATA AND SPECIFICATIONS (SDS) .... 331
General Specifications .......................................... 331
Vehicle Speed When Shifting Gears ..................... 331
Vehicle Speed When Performing and Releasing
Complete Lock-up ................................................. 332
Vehicle Speed When Performing and Releasing
Slip Lock-up .......................................................... 332
Stall Speed ............................................................ 332
Line Pressure ........................................................ 332
A/T Fluid Temperature Sensor .............................. 332
Turbine Revolution Sensor .................................... 332
Vehicle Speed Sensor A/T (Revolution Sensor) ... 332
Reverse brake ....................................................... 333
Total End Play ....................................................... 333

A/T FLUID
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A/T FLUIDPFP:KLE40
Changing A/T FluidUCS002C8
1. Increase ATF temperature by 80°C (176°F) once.
2. Stop engine.
3. Remove the tightening bolt for ATF level gauge.
4. Drain ATF from drain plug and refill with new ATF. Always refill same volume with drained fluid.

To replace the ATF, pour in new fluid at the charging pipe with the engine idling and at the same time
drain the old fluid from the radiator cooler hose return side.

When the color of the fluid coming out is about the same as the color of the new fluid, the replacement
is complete. The amount of new transmission fluid to use should be 30 to 50% increase of the stipu-
lated amount.
CAUTION:

Use only Genuine NISSAN ATF Matic Fluid J. Do not mix with other fluid.

Using automatic transmission fluid other than Genuine NISSAN ATF Matic Fluid J will cause
deterioration in driveability and automatic transmission durability, and may damage the auto-
matic transmission, which is not covered by the warranty.

When filling ATF, take care not to scatter heat generating parts such as exhaust.
5. Increase ATF temperature by 80°C (176°F) once.
6. Check fluid level and condition. Refer to AT-13, "
Checking A/T Fluid" . If fluid is still dirty, repeat step 2.
through 5.
7. Install the removed ATF level gauge in the fluid charging pipe.
Checking A/T FluidUCS002C9
1. Warm up engine.
2. Check for fluid leakage.
3. Remove the tightening bolt for ATF level gauge.
4. Before driving, fluid level can be checked at fluid temperatures of 30° to 50°C (86° to 122°F) using
“COLD” range on ATF level gauge as follows.
a. Park vehicle on level surface and set parking brake.
b. Start engine and move selector lever through each gear position. Leave selector lever in “P” position.
c. Check fluid level with engine idling.
d. Remove ATF level gauge and wipe clean with lint-free paper.
CAUTION:
When wiping away the fluid level gauge, always use lint-free paper, not a cloth one.
e. Re-insert ATF level gauge into charging pipe as far as it will go.
CAUTION:
To check fluid level, insert the ATF level gauge until the cap contacts the end of the charging pipe,
with the gauge reversed from the normal attachment conditions.
f. Remove ATF level gauge and note reading. If reading is at low side of range, add fluid to the charging
pipe.
CAUTION:
Do not overfill.
5. Increase ATF temperature by 80°C (176°F) once. ATF: NISSAN Matic Fluid J
Fluid capacity: 10.6 (11-1/4 US qt, 9-3/8 lmp qt)
Drain plug:
: 34 N·m (3.5 kg-m, 25 ft-lb)
Level gauge bolt:
: 5.1 N·m (0.52 kg-m, 45 in-lb)

A/T CONTROL SYSTEM
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TCM FunctionUCS002CE
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 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
LCIA0317E

ON BOARD DIAGNOSTIC (OBD) SYSTEM
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ON BOARD DIAGNOSTIC (OBD) SYSTEMPFP:00028
IntroductionUCS002CM
The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (OBD-II) performed by the TCM in combination
with the ECM. The malfunction is indicated by the MIL (malfunction indicator lamp) and is stored as a DTC in
the ECM memory but not the TCM memory.
The second is the TCM original self-diagnosis indicated by the A/T CHECK indicator lamp. The malfunction is
stored in the TCM memory. The detected items are overlapped with OBD-II self-diagnostic items. For detail,
refer to AT- 9 3 , "
SELF-DIAGNOSTIC RESULT MODE" .
OBD-II Function for A/T SystemUCS002C N
The ECM provides emission-related on board diagnostic (OBD-II) functions for the A/T system. One function
is to receive a signal from the TCM used with OBD-related parts of the A/T system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-related part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indicator lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in relation
to A/T system parts.
One or Two Trip Detection Logic of OBD-IIUCS002CO
ONE TRIP DETECTION LOGIC
If a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. — First Trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MIL will illuminate. — Second Trip
The “trip” in the “One or Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation.
OBD-II Diagnostic Trouble Code (DTC)UCS002CP
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
( with CONSULT-II or GST) CONSULT-II or GST (Generic Scan Tool) Examples: P0705, P0720 etc.
These DTC are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)

1st trip DTC No. is the same as DTC No.

Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST, they do not indicate whether the malfunction is still occurring
or occurred in the past and returned to normal.
CONSULT-II can identify them as shown below, therefore, CONSULT-II (if available) is recom-
mended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown
on the next page. DTC or 1st trip DTC of a malfunction is displayed
in SELF-DIAGNOSTIC RESULTS mode for “ENGINE” with CON-
SULT-II. Time data indicates how many times the vehicle was driven
after the last detection of a DTC.
BCIA0030E

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ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: August 20072004 QX56
Malfunction Indicator Lamp (MIL)UCS002CQ
DESCRIPTION
The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned “ON” with-
out the engine running. This is a bulb check.

If the MIL does not light up, refer to DI-31, "WARNING LAMPS"
.
2. When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction.
SEF 2 17 U

TROUBLE DIAGNOSIS
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TROUBLE DIAGNOSISPFP:00004
DTC Inspection Priority ChartUCS002C R
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-1 03
.
Fail-SafeUCS002CS
The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is a an error in
a main electronic control input/output signal circuit. In fail-safe mode the transmission is fixed in 2nd or 4th
(depending on the breakdown position), so the customer should feel “slipping” or “poor acceleration”. When
fail-safe mode is triggered, when the ignition switch is switched “ON”, the AT CHECK indicator lamp flashes for
about 8 seconds.
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. Also, the AT CHECK indicator lamp flashes for about 8 seconds once, then is cleared.
Therefore, the customer's vehicle has returned to normal, so handle according to the “diagnostics flow” (Refer
to AT-46, "
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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Revision: August 20072004 QX56
How To Perform Trouble Diagnosis For Quick and Accurate RepairUCS002CT
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, accelerator pedal position sensor (throttle position
sensor) or PNP switch and provides shift control or lock-up control via A/T solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used with the OBD-related parts of the
A/T system for malfunction-diagnostic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions in its memory.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a error that occurs intermittently
rather than continuously. Most intermittent errors are caused by poor
electric connections or improper wiring. In this case, careful check-
ing of suspected circuits may help prevent the replacement of good
parts.
A visual check only may not find the cause of the errors. A road test
with CONSULT-II (or GST) or a circuit tester connected should be
performed. Follow the AT-46, "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” as shown on
the example (Refer to AT- 4 7
) should be used.
Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.
SAT6 3 1IB
SAT6 3 2I
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