2009 INFINITI QX56 ECU

EC-472
< ECU DIAGNOSIS >[VK56DE]
ECM
MISFIRE A1H Multiple Cylinder MisfiresP0301 80H 24H
Misfiring counter at 1000 revolution of
the first cylinder
P0302 81H 24H Misfiring counter at 1000 revolution of
the second cylinder
P0303 82H 24H Misfiring counter at 1000 revolution of
the third cylinder
P0304 83H 24H Misfiring counter at 1000 revolution of
the fourth cylinder
P0305 84H 24H Misfiring counter at 1000 revolution of
the fifth cylinder
P0306 85H 24H Misfiring counter at 1000 revolution of
the sixth cylinder
P0307 86H 24H Misfiring counter at 1000 revolution of
the seventh cylinder
P0308 87H 24H Misfiring counter at 1000 revolution of
the eighth cylinder
P0300 88H 24H Misfiring counter at 1000 revolution of
the multiple cylinders
P0301 89H 24H Misfiring counter at 200 revolution of the
first cylinder
P0302 8AH 24H Misfiring counter at 200 revolution of the
second cylinder
P0303 8BH 24H Misfiring counter at 200 revolution of the
third cylinder
P0304 8CH 24H Misfiring counter at 200 revolution of the
fourth cylinder
P0305 8DH 24H Misfiring counter at 200 revolution of the
fifth cylinder
P0306 8EH 24H Misfiring counter at 200 revolution of the
sixth cylinder
P0307 8FH 24H Misfiring counter at 200 revolution of the
seventh cylinder
P0308 90H 24H Misfiring counter at 200 revolution of the
eighth cylinder
P0300 91H 24H Misfiring counter at 1000 revolution of
the single cylinder
P0300 92H 24H Misfiring counter at 200 revolution of the
single cylinder
P0300 93H 24H Misfiring counter at 200 revolution of the
multiple cylinders
Item
OBD-
MID Self-diagnostic test item DTC Test value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
Revision: December 20092009 QX56

ECM
EC-473
< ECU DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION
How to Erase DTC
WITH CONSULT-III
The emission related diagnostic information in the ECM can be erased by selecting “All Erase” in the “Descrip-
tion” of “FINAL CHECK” mode with CONSULT-III.
WITH GST
The emission related diagnostic information in the ECM can be erased by selecting Service $04 with GST.
NOTE:
If the DTC is not for A/T related items (see EC-456, "DTC Index"
), skip step 2.
MISFIREA2H No.1 Cylinder Misfire
P0301 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0301 0CH 24H Misfire counts for last/current driving cy-
cles
A3H No.2 Cylinder Misfire P0302 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0302 0CH 24H Misfire counts for last/current driving cy-
cles
A4H No.3 Cylinder Misfire P0303 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0303 0CH 24H Misfire counts for last/current driving cy-
cles
A5H No.4 Cylinder Misfire P0304 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0304 0CH 24H Misfire counts for last/current driving cy-
cles
A6H No.5 Cylinder Misfire P0305 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0305 0CH 24H Misfire counts for last/current driving cy-
cles
A7H No.6 Cylinder Misfire P0306 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0306 0CH 24H Misfire counts for last/current driving cy-
cles
A8H No.7 Cylinder Misfire P0307 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0307 0CH 24H Misfire counts for last/current driving cy-
cles
A9H No.8 Cylinder Misfire P0308 0BH 24H
EWMA (Exponential Weighted Moving
Average) misfire counts for last 10 driv-
ing cycles
P0308 0CH 24H Misfire counts for last/current driving cy-
cles
Item
OBD-
MID Self-diagnostic test item DTC Test value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
Revision: December 20092009 QX56

EC-474
< ECU DIAGNOSIS >[VK56DE]
ECM
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
2. Perform TM-30, "OBD-II Diagnostic Trouble Code (DTC)"
. (The DTC in TCM will be erased)
3. Select Service $04 with GST (Generic Scan Tool).
No Tools
NOTE:
If the DTC is not for AT related items (see EC-456, "DTC Index"
), skip step 2.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once.
Wait at least 10 seconds and then turn it ON (engine stopped) again.
2. Perform TM-30, "OBD-II Diagnostic Trouble Code (DTC)"
. (The DTC in the TCM will be erased.)
3. Change the diagnostic test mode from Mode II to Mode I by depressing the accelerator pedal. Refer to
EC-55, "Malfunction Indicator Lamp (MIL)"
.
 If the battery is disconnected, the emission-related diagnostic information will be lost within 24
hours.
 The following data are cleared when the ECM memory is erased.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
Actual work procedures are explained using a DTC as an ex ample. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
Revision: December 20092009 QX56

EC-480
< PRECAUTION >[VK56DE]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint S
ystem (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005867525
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 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 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 NISS AN/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 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 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.
On Board Diagnosis (OBD) System of Engine and A/TINFOID:0000000003771742
The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
 Be sure to turn the ignition sw itch OFF and disconnect the negative battery cable before any repair
or inspection work. The open/short circuit of re lated switches, sensors, solenoid valves, etc. will
cause the MIL to light up.
 Be sure to connect and lock the connectors secure ly after work. A loose (unlocked) connector will
cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
 Certain systems and components, especially those related to OBD, may use a new style slide-lock-
ing type harness connector. For descrip tion and how to disconnect, refer to PG-68
.
 Be sure to route and secure the harnesses properly after work. The interference of the harness with
a bracket, etc. may cause the MIL to li ght up due to the short circuit.
 Be sure to connect rubber tubes properly afte r work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to the malfunction of the EVAP system or fuel injection system,
etc.
 Be sure to erase the unnecessary malfunction info rmation (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
Revision: December 20092009 QX56

PRECAUTIONSEC-481
< PRECAUTION > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
PrecautionINFOID:0000000003771743

Always use a 12 volt battery as power source.
 Do not attempt to disconnect battery cables while engine is
running.
 Before connecting or disc onnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative bat-
tery cable. Failure to do so may damage the ECM because
battery voltage is applied to ECM even if ignition switch is
turned OFF.
 Before removing parts, turn ig nition switch OFF and then dis-
connect negative battery cable.
 Do not disassemble ECM.
 If a battery cable is disconnect ed, the memory will return to
the ECM value.
The ECM will now start to sel f-control at its initial value.
Engine operation can vary slight ly when the terminal is dis-
connected. However, this is no t an indication of a malfunc-
tion. Do not replace parts b ecause of a slight variation.
 If the battery is disconnected, the following emission-related
diagnostic information will be lost within 24 hours.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
 When connecting ECM harness c onnector, fasten it securely
with a lever as far as it will go as shown in the figure.
 When connecting or disconnect ing pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM pin
terminal, when conn ecting pin connectors.
 Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge) volt-
age to develop in coil and cond enser, thus resulting in dam-
age to ICs.
 Keep engine control system harness at least 10 cm (4 in) away
from adjacent harness, to prevent engine control system mal-
functions due to receiving externa l noise, degraded operation
of ICs, etc.
 Keep engine control system parts and harness dry.
SEF289H
PBIB1164E
BBIA0387E
PBIB0090E
Revision: December 20092009 QX56

EVAP LEAK CHECKEC-489
< ON-VEHICLE MAINTENANCE > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
EVAP LEAK CHECK
How to Detect Fuel Vapor LeakageINFOID:0000000003771747
CAUTION:
 Never use compressed air
or a high pressure pump.
 Do not exceed 4.12 kPa (0.042 kg/cm
2, 0.6 psi) of pressure in EVAP system.
NOTE:
 Do not start engine.
 Improper installation of EVAP service port adapter to the EVAP service port may cause a leak.
WITH CONSULT-IIl
1. Attach the EVAP service port adapter securely to the EVAP service port.
2. Also attach the pressure pump and hose to the EVAP service port adapter.
3. Turn ignition switch ON.
4. Select the “EVAP SYSTEM CLOSE” of “WORK SUPPORT MODE” with CONSULT-IIl.
5. Touch “START”. A bar graph (Pressure indicating display) will appear on the screen.
6. Apply positive pressure to the EVAP system until t he pressure indicator reaches the middle of the bar
graph.
7. Remove EVAP service port adapter and hose with pressure pump.
8. Locate the leak using a leak detector. Refer to EC-37, "Descrip-
tion".
WITHOUT CONSULT-IIl
1. Attach the EVAP service port adapter securely to the EVAP ser-
vice port.
2. Also attach the pressure pump with pressure gauge to the EVAP service port adapter.
SEF200U
BBIA0366E
SEF462UA
Revision: December 20092009 QX56

EM-14
< ON-VEHICLE MAINTENANCE >
DRIVE BELTS
2. Install Tool on drive belt auto tensioner pulley bolt, move in thedirection of arrow (loosening direction of tensioner) as shown.
WARNING:
Avoid placing hand in a locatio n where pinching may occur
if the holding tool accidentally comes off.
3. Remove the drive belt.
INSTALLATION
Installation is in the reverse order of removal.
CAUTION:
Make sure belt is securely installed around all pulleys.
• Rotate the crankshaft pulley several turns clockwise to equalize belt tension between pulleys.
• Make sure belt tension is within the allowable working range, using the indicator notch on the drive belt auto tensioner. Refer to EM-13, "
Checking Drive Belts".
Drive Belt Auto Tensioner and Idler PulleyINFOID:0000000005885864
REMOVAL
1. Remove the drive belt. Refer to EM-13, "Removal and Installation".
2. Remove the drive belt auto tensioner and idler pulley using power tool.
INSTALLATION
Installation is in the reverse order of removal. Tool number : — (J-46535)
WBIA0537E
WBIA0607E
1. Drive belt auto tensioner
2. Idler pulley
Revision: December 20092009 QX56

EM-42
< ON-VEHICLE REPAIR >
FUEL INJECTOR AND FUEL TUBE
• Lubricate O-ring with new engine oil.
• Do not clean O-ring with solvent.
• Make sure that O-ring and its mating part are free of foreign material.
• When installing O-ring, be careful not to scratch it with tool or fingernails. Also be careful not to
twist or stretch O-ring. If O-ring was stretc hed while it was being attached, do not insert it
quickly into fuel tube.
• Insert O-ring straight into fuel tube. Do not angle or twist it.
3. Install fuel injector to fuel tube.
a. Insert clip into clip mounting groove on fuel injector. • Insert clip so that lug “A” of fuel injector matches notch “A” ofthe clip.
CAUTION:
• Do not reuse clip. Replace it with a new one.
• Be careful to keep clip from interfering with O-ring. Ifinterference occurs, replace O-ring.
b. Insert fuel injector into fuel tube with clip attached. • Insert it while matching it to the axial center.
• Insert fuel injector so that lug “B” of fuel tube matches notch
“B” of the clip.
• Make sure that fuel tube flange is securely fixed in flange fixing groove on clip.
c. Make sure that installation is complete by checking that fuel injector does not rotate or come off.
• Make sure that protrusions of fuel injectors are aligned withcutouts of clips after installation.
4. Install fuel tube and fuel injector assembly to intake manifold. CAUTION:
Be careful not to let tip of injector nozzle come in contact with other parts.
• Tighten fuel tube assembly bolts “a” to “b” in illustration and in
two steps.
5. Install fuel hose assembly. • Follow the precautions for fuel injector when handling O-ring.
• Insert connectors straight, making sure that the axis is lined up with fuel tube side to prevent O-ring from
being damaged.
• Tighten bolts evenly in several steps.
• Make sure that there is no gap between flange and fuel tube after tightening bolts.
6. Installation of the remaining components is in the reverse order of removal.
INSPECTION AFTER INSTALLATION
After installing fuel tubes, make sure there are no fuel leaks at connections using the following steps.
1. Apply fuel pressure to fuel lines by turning ignition switch ON (with engine stopped). Then check for fuel leaks at connections.
2. Start the engine and rev it up and check for fuel leaks at connections. WARNING:
KBIA2507E
1st step : 12.8 N·m (1.3 kg-m, 9 ft-lb)
2nd step : 24.5 N·m (2.5 kg-m, 18 ft-lb)
KBIA2474E
Revision: December 20092009 QX56