Electrical INFINITI QX56 2008 Factory Service Manual

TCM
TM-103
< ECU DIAGNOSIS >
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ECU DIAGNOSIS
TCM
Reference ValueINFOID:0000000001604173
REFERENCE VALUES
NOTICE:
1. The CONSULT-III electrically displays shift timi ng and lock-up timing (that is, operation timing of each
solenoid).
Check for time difference between actual shift timi ng and the CONSULT-III display. If the difference is
noticeable, mechanical parts (except solenoids, sens ors, etc.) may be malfunctioning. Check mechanical
parts using applicable diagnostic procedures.
2. Shift schedule (which implies gear position) display ed on CONSULT-III and that indicated in Service Man-
ual may differ slightly. This occurs because of the following reasons:
- Actual shift schedule has more or less tolerance or allowance,
- Shift schedule indicated in Service Manual re fers to the point where shifts start, and
- Gear position displayed on CONSULT-III indicates the point where shifts are completed.
3. Display of solenoid valves on CONSULT-III changes at the start of shifting, while gear position is displayed upon completion of shifting (which is computed by TCM).
Item name Condition Display value (Approx.)
ATF TEMP SE 1 0°C (32 ° F) - 20 °C (68 °F) - 80 °C (176 °F) 3.3 - 2.7 - 0.9 V
ATF TEMP SE 2 3.3 - 2.5 - 0.7 V
TCC SOLENOID When perform slip lock-up
0.2 - 0.4 A
When perform lock-up 0.4 - 0.6 A
SLCT LVR POSI Selector lever in
“N”,“P” position. N/P
Selector lever in “R” position. R
Selector lever in “D” position. D
Selector lever in “4” position. 4
Selector lever in “3” position. 3
Selector lever in “2” position. 2
Selector lever in “1” position. 1
VHCL/S SE·A/T During driving Approximately matches the
speedometer reading.
ENGINE SPEED Engine running Closely matches the tachometer
reading.
LINE PRES SOL During driving 0.2 - 0.6 A
INPUT SPEED During driving (lock-up ON) Approximately matches the en-
gine speed.
VHCL/S SE·MTR During driving Approximately matches the
speedometer reading.
ATF PRES SW 2 Low coast brake engaged. Refer to
TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
I/C SOLENOID Input clutch disengaged. Refer to
TM-9
0.6 - 0.8 A
Input clutch engaged. Refer to TM-9
0 - 0.05 A
FR/B SOLENOID Front brake engaged. Refer to
TM-9
0.6 - 0.8 A
Front brake disengaged. Refer to TM-9
0 - 0.05 A
D/C SOLENOID Direct clutch disengaged. Refer to
TM-9
0.6 - 0.8 A
Direct clutch engaged. Refer to TM-9
0 - 0.05 A
HLR/C SOL High and low reverse clutch disengaged. Refer to
TM-9
0.6 - 0.8 A
High and low reverse clutch engaged. Refer to TM-9
0 - 0.05 A
Revision: March 2010 2008 QX56

TM-114
< ECU DIAGNOSIS >
TCM
Fail-Safe
INFOID:0000000001604175
The TCM has an electrical fail-safe mode. This mode make s it possible to operate even if there is an error in a
main electronic control input/output signal circuit.
The TCM has an electrical fail-safe mode. This mode make s it possible to operate even if there is an error in a
main electronic control input/output signal circuit. In fa il-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”.
AADIA0076GB
Revision: March 2010 2008 QX56

TCM
TM-115
< ECU DIAGNOSIS >
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Even when the electronic circuits are normal, under s pecial 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 TM-5, "
Work Flow").
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, th is function controls the A/T to mark driving possible.
Output Speed Sensor
• Signals are input from two systems - from output s peed sensor installed on the transmission and from com-
bination meter so normal driving is possible even if t here is a malfunction in one of the systems. And if output
speed sensor has unusual cases, 5GR is prohibited.
Accelerator Pedal Position Sensor
• If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM according
to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow sys-
tems, 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 according
to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow sys-
tems, 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.
Transmission Range Switch
• In the unlikely event that a malfunction signal enters t he 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.)
Interlock
• If there is an interlock judgment malfunction, the tr ansmission is fixed in 2GR to make driving possible.
NOTE:
When the vehicle is driven fixed in 2GR, a inpu t speed sensor malfunction is displayed, but this is
not a input speed sensor malfunction.
• When the interlock is detected at the 3GR or more, it is locked at the 2GR.
1st Engine Braking
• When there is an 1st engine brake judgment malfunction, the low coast brake solenoid is switched “OFF” to
avoid the engine brake operation.
Line Pressure Solenoid
• The solenoid is switched “OFF” and the line pressure is set to the maximum hydraulic pressure to make driv- ing possible.
Torque Converter Clutch Solenoid
• The solenoid is switched “OFF” to release the lock-up.
Low Coast Brake Solenoid
• When a (electrical or functional) malfunction occurs, in order to make driving possible, the engine brake is
not applied in 1GR and 2GR.
Input Clutch Solenoid
• If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4th gear to make driving possible.
Direct Clutch Solenoid
• If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4GR to make driving possible.
Front Brake Solenoid
• If a (electrical or functional) malfunction occurs with the solenoid “ON”, in order to make driving possible, the
A/T is held in 5GR; if the solenoid is OFF, 4GR.
Revision: March 2010 2008 QX56

TM-116
< ECU DIAGNOSIS >
TCM
High and Low Reverse Clutch Solenoid
• If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4GR to make driving possible.
Input Speed Sensor 1 or 2
• The control is the same as if there were no turbine revolution sensors, 5GR is prohibited.
DTC Inspection Priority ChartINFOID:0000000001604176
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
TM-38, "
Diagnosis Procedure".
DTC No. IndexINFOID:0000000001604177
NOTE:
If DTC U1000 is displayed with other DTC, first pe rform the trouble diagnosis for DTC U1000. Refer to
TM-38, "
Diagnosis Procedure".
Priority Detected items (DTC)
1 U1000 CAN COMM CIRCUIT
2 Except above
DTC
Items
(CONSULT- III screen terms) Reference page
OBD- II
Except OBD- II
CONSULT- III GST (*1) CONSULT- III only
“TRANSMISSION”
— P0615STARTER RELAY TM-39
P0700P0700TRANSMISSION CONT TM-42
P0705P0705T/M RANGE SWITCH A TM-43
P0710P1710TRANS FLUID TEMP SEN TM-71
P0717P0717INPUT SPEED SENSOR A TM-46
P0720P0720OUTPUT SPEED SENSOR TM-49
—P0725ENGINE SPEED TM-51
P0731P07311GR INCORRECT RATIO TM-54
P0732P07322GR INCORRECT RATIO TM-56
P0733P07333GR INCORRECT RATIO TM-58
P0734P07344GR INCORRECT RATIO TM-60
P0735P07355GR INCORRECT RATO TM-62
P0740P0740TORQUE CONVERTER TM-63
P0744 P0744 TORQUE CONVERTER TM-66
P0745P0745PC SOLENOID A TM-67
—P1705TP SENSOR TM-69
—P1721VEHICLE SPEED SIGNAL TM-74
P1730P1730INTERLOCK TM-76
—P17311GR E/BRAKING TM-78
P1752P1752INPUT CLUTCH SOL TM-80
P1757P1757FR BRAKE SOLENOID TM-82
P1762P1762DRCT CLUTCH SOL TM-84
P1767P1767HLR CLUTCH SOLENOID TM-86
Revision: March 2010 2008 QX56

PRECAUTIONSTM-173
< PRECAUTION >
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PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006054118
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 severi ty 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 w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoper ative, 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 performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Un it or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or el ectric power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers, always switch the Ignition OFF, disconnect the battery, and wait at least 3 minutes before performing any service.
Precaution Necessary for Steering Wheel Rotation After Battery Disconnect
INFOID:0000000004857582
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecti ng both battery cables with the ignition knob in the
″ LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS , an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery power is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be
rotated.
4. Perform the necessary repair operation.
Revision: March 2010 2008 QX56

VTL-2
< PRECAUTION >
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004884177
The Supplemental Restraint System such as “A IR 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 w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inopera tive, 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 performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers , always switch the Ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation After Battery Disconnect
INFOID:0000000004884178
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
4. Perform the necessary repair operation.
Revision: March 2010 2008 QX56

INTAKE SENSORVTL-11
< ON-VEHICLE REPAIR >
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INTAKE SENSOR
Removal and InstallationINFOID:0000000001516606
REMOVAL
1. Remove the instrument panel. Refer to IP-12, "Removal and Installation".
2. Disconnect the intake sensor electrical connector. NOTE:
The intake sensor is located on the top of the front heater and
cooling unit assembly next to the A/C evaporator cover.
3. Twist the intake sensor to remove the intake sensor from the front heater and cooling unit assembly.
INSTALLATION
Installation is in the reverse order of removal.
LJIA0133E
Revision: March 2010 2008 QX56

VTL-12
< ON-VEHICLE REPAIR >
BLOWER MOTOR
BLOWER MOTOR
ComponentINFOID:0000000001516607
Front Blower MotorRear Blower Motor
Removal and InstallationINFOID:0000000001516608
FRONT BLOWER MOTOR
Removal
1. Remove the glove box assembly. Refer to IP-17, "Removal and Installation".
2. Disconnect the front blower motor electrical connector.
3. Remove the three screws and remove the front blower motor.
Installation
Installation is in the reverse order of removal.
LJIA0136E
1. Front heater and cooling unit assembly 2. Front blower motor 3. Front variable blower control
AWIIA0085ZZ
1. Rear blower motor2. Rear heater and cooling unit assembly 3. Rear variable blower control
Revision: March 2010 2008 QX56

BLOWER MOTORVTL-13
< ON-VEHICLE REPAIR >
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REAR BLOWER MOTOR
Removal
1. Remove the luggage side lower finisher RH. Refer to INT-19, "Removal and Installation".
2. Disconnect the rear blower motor electrical connector.
3. Remove the three screws and remove the rear blower motor.
Installation
Installation is in the reverse order of removal.
Revision: March 2010 2008 QX56

HEATER & COOLING UNIT ASSEMBLYVTL-17
< ON-VEHICLE REPAIR >
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1. Move the two front seats to the rear most position on the seat track.
2. Disconnect the battery negative terminal and battery positive terminal.
3. Discharge the refrigerant from the A/C system. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
4. Drain the coolant from the engine cooling system. Refer to CO-11, "
Changing Engine Coolant".
5. Disconnect the front heater hoses from the front heater core.
6. Disconnect the high/low pressure pipes from the front expansion valve.
7. Remove the instrument panel and console panel. Refer to IP-12, "
Removal and Installation".
8. Remove the steering column. Refer to ST-20, "
Removal and Installation".
9. Disconnect the instrument panel wire harness at t he RH and LH in-line connector brackets, and the fuse
block (J/B) electrical connectors. Refer to PG-9, "
Wiring Diagram — Battery Power Supply —".
10. Disconnect the steering member from each side of the vehicle body.
11. Remove the front heater and cooling unit assembly with it attached to the steering member, from the vehi- cle.
CAUTION:
Use care not to damage the seats and interior trim panels when removing the front heater and
cooling unit assembly with it at tached to the steering member.
12. Remove the front heater and cooling uni t assembly from the steering member.
Installation
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply com-
pressor oil to it when installing it.
• After charging the refrigerant, check for leaks.
NOTE:
• Fill the engine cooling system with the specified coolant mixture. Refer to CO-11, "
Changing Engine Cool-
ant".
• Recharge the A/C system. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
REAR HEATER AND COOLING UNIT ASSEMBLY
Removal
1. Discharge the refrigerant from the A/C system. Refer to HA-20, "HFC-134a (R-134a) Service Procedure".
2. Drain the coolant from the engine cooling system. Refer to CO-11, "
Changing Engine Coolant".
3. Remove the luggage side finisher lower RH. Refer to INT-19, "
Removal and Installation".
4. Disconnect the rear heater core hoses from the rear heater core.
5. Disconnect the rear A/C pipes from the rear expansion valve.
6. Disconnect the following electrical connectors: • Rear blower motor
• Rear variable blower control
• Rear air mix door motor
7. Disconnect the ducts from the rear heater and cooling unit assembly.
8. Remove the rear heater and cooling unit assembly.
Installation
Installation is in the reverse order of removal.
CAUTION:
• Replace the O-ring of the low-pressure pipe and high-pressure pipe with a new one, and apply com- pressor oil to it when installing it.
• After charging the refrigerant, check for leaks.
NOTE:
• Fill the engine cooling system with the specified coolant mixture. Refer to CO-11, "
Changing Engine Cool-
ant".
• Recharge the A/C system. Refer to HA-20, "
HFC-134a (R-134a) Service Procedure".
Revision: March 2010 2008 QX56