2010 INFINITI QX56 Ignition switch

ECM
EC-433
< ECU DIAGNOSIS > [VK56DE]
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99 G/R
ASCD steering switch
(Models with ASCD system) [Ignition switch: ON]
• ASCD steering switch: OFF
Approximately 4V
[Ignition switch: ON]
• MAIN switch: Pressed Approximately 0V
[Ignition switch: ON]
• CANCEL switch: Pressed Approximately 1V
[Ignition switch: ON]
• RESUME/ACCELERATE switch: Pressed Approximately 3V
[Ignition switch: ON]
• SET/COAST switch: Pressed Approximately 2V
101 R/W Stop lamp switch [Ignition switch: OFF]
• Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
• Brake pedal: Slightly depressed BATTERY VOLTAGE
(11 - 14V)
102 GR/R PNP signal [Ignition switch: ON]
• Selector lever: P or N
Approximately 0V
[Ignition switch: ON]
• Except the above gear position BATTERY VOLTAGE
(11 - 14V)
104 O Throttle cont rol motor relay[Ignition switch: OFF]
BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON] 0 - 1.0V
106 BR/W Accelerator pedal position
sensor 1 [Ignition switch: ON]
• Engine: Stopped
• Accelerator pedal: Fully released
0.5 - 1.0V
[Ignition switch: ON]
• Engine: Stopped
• Accelerator pedal: Fully depressed 4.2 - 4.8V
107 V/R Fuel tank temperature sensor [Engine is running]Approximately 0 - 4.8V
Output voltage varies with fuel
tank temperature.
108 BR/W ICC brake switch
(Models with ICC system)
ASCD brake switch
(Models with ASCD system) [Ignition switch: ON]
• Brake pedal: Slightly depressed
Approximately 0V
[Ignition switch: ON]
• Brake pedal: Fully released BATTERY VOLTAGE
(11 - 14V)
109 L/W Ignition switch [Ignition switch: OFF]
0V
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
111 W / B ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]
• For a few seconds after turning ignition
switch OFF 0 - 1.5V
[Ignition switch: OFF]
• More than a few seconds after turning igni- tion switch OFF BATTERY VOLTAGE
(11 - 14V)
11 3 G R F u e l p u m p r e l a y [Ignition switch: ON]
• For 1 second after turning ignition switch
ON
[Engine is running] 0 - 1.5V
[Ignition switch: ON]
• More than 1 second after turning ignition switch ON BATTERY VOLTAGE
(11 - 14V)
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COLOR ITEM
C

ONDITIONDATA (DC Voltage)
Revision: April 20092010 QX56

EC-434
< ECU DIAGNOSIS >[VK56DE]
ECM
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
*:Before measuring the terminal voltage, confirm that the battery is fully charged. Refer to PG-74
.
11 5
11 6
B
B/W
ECM ground [Engine is running]
• Idle speed Body ground
11 7 L / Y EVAP canister vent control
valve
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
11 9
120 BR
BR
Power supply for ECM
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
121 W Power supply for ECM
(Back-up) [Ignition switch: OFF] BATTERY VOLTAGE
(11 - 14V)
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COLOR ITEM
CONDITION DATA (DC Voltage)
Revision: April 20092010 QX56

ECM
EC-457
< ECU DIAGNOSIS > [VK56DE]
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• When there is an open circuit on MIL circuit, the ECM c
annot warn the driver by lighting up MIL when there
is malfunction on engine control system.
Therefore, when electrical controlled throttle and pa rt of ECM related diagnoses are continuously detected
as NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by
means of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands the
driver to repair the malfunction.
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103 Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118 Engine coolant tempera-
ture sensor circuit Engine coolant temperature will be determined by ECM based on the following condition.
CONSULT-IIl displays the engine coolant temperature decided by ECM.
Condition Engine coolant temperature decided
(CONSULT-IIl display)
Just as ignition switch is turned ON
or START 40
°C (104 °F)
Approx 4 minutes or more after en-
gine starting. 80
°C (176 °F)
Except as shown above 40 - 80°
C (104 - 176 °F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling
fan operates while engine is running.
P0122
P0123
P0222
P0223
P2135 Throttle position sensor The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
P0643 Sensor power supply ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2100
P2103 Throttle control motor relay ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2101 Electric th rottle control
function ECM stops the electric throttle control actuator control, throttle valve is maintained at a
fixed opening (approx. 5 degrees) by the return spring.
P2118 Throttle control motor ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return spring.
P2119 Electric thro ttle control ac-
tuator (When electric throttle control actuator does not function properly due to the return spring
malfunction:)
ECM controls the electric throttle actuator by regulating the throttle opening around the
idle position. The engine speed will not rise more than 2,000 rpm.
(When throttle valve opening angle in fail-safe mode is not in specified range:)
ECM controls the electric throttle control actuator by regulating the throttle opening to 20
degrees or less.
(When ECM detects the throttle valve is stuck open:)
While the vehicle is driving, it slows down gradually by fuel cut. After the vehicle stops, the
engine stalls.
The engine can restart in N or P position, and engine speed will not exceed 1,000 rpm or
more.
P2122
P2123
P2127
P2128
P2138 Accelerator pedal position
sensor
The ECM controls the electric throttle control actuator in regulating the throttle opening in
order for the idle position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal
condition.
So, the acceleration will be poor.
Engine operating condition in fail-safe mode
Engine speed will not rise more than 2,500 rpm due to the fuel cut
Revision: April 20092010 QX56

ECM
EC-467
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NO TOOLS
A SRT code itself can not be displayed while only SRT status can be.
1. Turn ignition switch ON and wait 20 seconds.
2. SRT status is indicated as shown below. • When all SRT codes are set, MIL lights up continuously.
• When any SRT codes are not set, MIL will flash periodically for 10 seconds.
How to Set SRT Code
To set all SRT codes, self-diagnosis for the items indicated above must be performed one or more times. Each
diagnosis may require a long period of actual driving under various conditions.
WITH CONSULT-III
Perform corresponding DTC Confirmation Procedure one by one based on Performance Priority in the table
on "SRT Item".
WITHOUT CONSULT-III
The most efficient driving pattern in which SRT codes can be properly set is explained on the next page. The
driving pattern should be performed one or more times to set all SRT codes.
PBIB2317E
Revision: April 20092010 QX56

EC-476
< 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-459, "
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 example. 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: April 20092010 QX56

EC-482
< PRECAUTION >[VK56DE]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint Syst
em (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000005149502
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 SRS 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 SRS 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.
On Board Diagnosis (OBD) S ystem of Engine and A/TINFOID:0000000005149503
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 switch 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-64
.
• 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.
PrecautionINFOID:0000000005149504
•Always use a 12 volt battery as power source.
• Do not attempt to disconnect battery cables while engine is
running.
• Before connecting or disconnecting 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.
SEF289H
Revision: April 20092010 QX56

FUEL PRESSUREEC-489
< ON-VEHICLE MAINTENANCE > [VK56DE]
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ON-VEHICLE MAINTENANCE
FUEL PRESSURE
Fuel Pressure CheckINFOID:0000000005149507
FUEL PRESSURE RELEASE
With CONSULT-IIl
1. Turn ignition switch ON.
2. Perform “FUEL PRESSURE RELEASE” in
“WORK SUPPORT” mode with CONSULT-IIl.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
Without CONSULT-IIl
1. Remove fuel pump fuse located in IPDM E/R.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel pressure.
4. Turn ignition switch OFF.
5. Reinstall fuel pump fuse after servicing fuel system.
FUEL PRESSURE CHECK
CAUTION:
• Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.
• Be careful not to scratch or get the fuel hose connection area dirty when servicing, so that the quick connector o-ring maintains sealability.
• Use Fuel Pressure Gauge Kit J-44321 and Fuel Pr essure Adapter J-44321-6 to check fuel pressure.
• Do not perform fuel pressure check with electrical system operating (i.e. lights, rear defog, A/C, etc.).
Fuel pressure gauge may indicate false readings du e to varying engine loads and changes in mani-
fold vacuum.
NOTE:
Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel pres-
sure cannot be completely released because JA60 models do not have fuel return system.
1. Release fuel pressure to zero. Refer to "FUEL PRESSURE RELEASE".
2. Remove engine cover.
3. Remove fuel hose using Quick Connector Release J-45488. Refer to EM-26
.
• Do not twist or kink fuel hose because it is plastic hose.
• Do not remove fuel hose from quick connector.
• Keep fuel hose connections clean.
4. Install Fuel Pressure Adapter J-44321-6 and Fuel Pressure Gauge (from kit J-44321) as shown in figure.
• Do not distort or bend fuel rail tube when installing fuel pres-sure gauge adapter.
• When reconnecting fuel hose, che ck the original fuel hose for
damage and abnormality.
5. Turn ignition switch ON (reactivate fuel pump), and check for fuel leakage.
6. Start engine and check for fuel leakage.
7. Read the indication of fuel pressure gauge. • During fuel pressure check, check for fuel leakage from fuel
connection every 3 minutes.
BBIA0380E
BBIA0390E
Revision: April 20092010 QX56

EVAP LEAK CHECKEC-491
< ON-VEHICLE MAINTENANCE > [VK56DE]
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EVAP LEAK CHECK
How to Detect Fuel Vapor LeakageINFOID:0000000005149508
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 the 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: April 20092010 QX56