2006 INFINITI QX56 check engine

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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-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-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
SCIA5624E

AT-38
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Revision: November 20092006 QX56
ON BOARD DIAGNOSTIC (OBD) SYSTEMPFP:00028
IntroductionECS00CE4
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- 8 6 , "
SELF-DIAGNOSTIC RESULT MODE" .
OBD-II Function for A/T SystemECS00CE5
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-IIECS00CE6
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. — 1st Trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MIL will illuminate. — 2nd 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)ECS00CE7
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

ON BOARD DIAGNOSTIC (OBD) SYSTEMAT-41
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Malfunction Indicator Lamp (MIL)ECS00CE8
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.
SEF217U

AT-44
TROUBLE DIAGNOSIS
Revision: November 20092006 QX56
How To Perform Trouble Diagnosis For Quick and Accurate RepairECS00CEB
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- 4 5 , "
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 6
) 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.
SAT631IB
SAT632I
SEF234G

TROUBLE DIAGNOSISAT-47
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Revision: November 2009 2006 QX56
4❏
Perform all road tests and enter checks in required inspection items. AT- 5 4
4-1.Check before engine is started
AT- 5 5
❏ AT- 1 7 9 , "A/T CHECK Indicator Lamp Does Not Come On" .
❏ Perform self-diagnostics Enter checks for detected items. AT- 8 6
❏ AT-96, "DTC U1000 CAN COMMUNICATION LINE"
❏ AT-100, "DTC P0615 START SIGNAL CIRCUIT"
❏ AT-104, "DTC P0700 TCM"
❏ AT-105, "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
❏ AT-109, "DTC P0717 TURBINE REVOLUTION SENSOR"
❏ AT- 111 , "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)"
❏ AT-116, "DTC P0725 ENGINE SPEED SIGNAL"
❏ AT-118, "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
❏ AT-120, "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
❏ AT-122, "DTC P0745 LINE PRESSURE SOLENOID VALVE"
❏ AT-124, "DTC P1705 THROTTLE POSITION SENSOR"
❏ AT-127, "DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT"
❏ AT-132, "DTC P1721 VEHICLE SPEED SENSOR MTR"
❏ AT-134, "DTC P1730 A/T INTERLOCK"
❏ AT-137, "DTC P1731 A/T 1ST ENGINE BRAKING"
❏ AT-139, "DTC P1752 INPUT CLUTCH SOLENOID VALVE"
❏ AT-141, "DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION"
❏ AT-143, "DTC P1757 FRONT BRAKE SOLENOID VALVE"
❏ AT-145, "DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION"
❏ AT-147, "DTC P1762 DIRECT CLUTCH SOLENOID VALVE"
❏ AT-149, "DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION"
❏ AT-151, "DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE"
❏ AT-153, "DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
FUNCTION"
❏ AT-155, "DTC P1772 LOW COAST BRAKE SOLENOID VALVE"
❏ AT-157, "DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION"
❏ AT-159, "DTC P1841 ATF PRESSURE SWITCH 1"
❏ AT-161, "DTC P1843 ATF PRESSURE SWITCH 3"
❏ AT-163, "DTC P1845 ATF PRESSURE SWITCH 5"
❏ AT-165, "DTC P1846 ATF PRESSURE SWITCH 6"
4-2. Idle inspection
AT- 5 5
❏ AT- 1 7 9 , "Engine Cannot Be Started In “P” or “N” Position"
❏ AT- 1 8 0 , "In “P” Position, Vehicle Moves When Pushed"
❏ AT- 1 8 1 , "In “N” Position, Vehicle Moves"
❏ AT- 1 8 2 , "Large Shock (“N” to “D” Position)"
❏ AT- 1 8 6 , "Vehicle Does Not Creep Backward In “R” Position"
❏ AT- 1 8 9 , "Vehicle Does Not Creep Forward In “D” Position"
4-3. Driving tests
AT- 5 6
Part 1
❏ AT- 1 9 1 , "
Vehicle Cannot Be Started From D1"
❏ AT- 1 9 4 , "A/T Does Not Shift: D1 → D2"
❏ AT- 1 9 6 , "A/T Does Not Shift: D2 → D3"
❏ AT- 1 9 8 , "A/T Does Not Shift: D3 → D4"
❏ AT- 2 0 1 , "A/T Does Not Shift: D4 → D5"
❏ AT- 2 0 3 , "A/T Does Not Perform Lock-up"
❏ AT- 2 0 5 , "A/T Does Not Hold Lock-up Condition"
❏ AT- 2 0 7 , "Lock-up Is Not Released"
❏ AT- 2 0 8 , "Engine Speed Does Not Return to Idle"