2006 INFINITI QX56 engine

DTC P0127 IAT SENSOREC-209
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
b. Select “DATA MONITOR ” mode with CONSULT-II.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 90 °C (194 °F),
turn ignition switch OFF and cool down engine.

Perform the following steps before engine coolant tempera-
ture is above 90 °C (194 °F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR ” mode with CONSULT-II.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 con- secutive seconds.
6. If 1st trip DTC is detected, go to EC-209, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00H27
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-210, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
3. CHECK INTERMITTENT INCIDENT
Refer to EC-144, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-189, "
Wiring Diagram" .
>> INSPECTION END
SEF189Y
BBIA0354E

DTC P0128 THERMOSTAT FUNCTIONEC-211
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
DTC P0128 THERMOSTAT FUNCTIONPFP:21200
On Board Diagnosis LogicUBS00H2A
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leak in the seal or the thermostat stuck open.
DTC Confirmation ProcedureUBS00H2B
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:

For best results, perform at ambient temperature of –10°C (14 °F) or higher.

For best results, perform at engine coolant temperature of –10 °C (14 °F) to 60 °C (140 °F).
WITH CONSULT-II
1. Replace thermostat with new one. Refer to CO-21, "THERMOSTAT AND WATER PIPING" . Use only a
genuine NISSAN thermostat as a replacement. If an incorrect thermostat is used, the MIL may come on.
2. Turn ignition switch ON.
3. Select “COOLAN TEMP/S ” in “DATA MONITOR ” mode with CONSULT-II.
4. Check that the “COOLAN TEMP/S” is above 60°C (140 °F).
If it is below 60 °C (140 °F), go to following step.
If it is above 60 °C (140 °F), cool down the engine to less than 60 °C (140 °F), then retry from step 1.
5. Drive vehicle for 10 consecutive minutes under the following conditions.
If 1st trip DTC is detected, go to EC-211, "
Diagnostic Procedure" .
WITH GST
1. Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureUBS00H2C
1. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-212, "
Component Inspection" .
OK or NG
OK >> INSPECTION END
NG >> Replace engine coolant temperature sensor.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128
0128 Thermostat function The engine coolant temperature does not
reach to specified temperature even though
the engine has run long enough.

Thermostat

Leakage from sealing portion of thermostat

Engine coolant temperature sensor
VHCL SPEED SE
80 - 120 km/h (50 - 75 MPH)

EC-212Revision: November 2009
DTC P0128 THERMOSTAT FUNCTION
2006 QX56
Component InspectionUBS00H2D
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensorterminals as shown in the figure.

2. If NG, replace engine coolant temperature sensor.
Removal and InstallationUBS00H2E
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-21, "THERMOSTAT AND WATER PIPING" .
PBIB2005E
Temperature °C (°F) Resistance kΩ
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.0
90 (194) 0.236 - 0.260
SEF012P

DTC P0130, P0150 A/F SENSOR 1EC-213
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
DTC P0130, P0150 A/F SENSOR 1PFP:22693
Component DescriptionUBS00HA7
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800 °C (1,292 - 1,472 °F).
CONSULT-II Reference Value in Data Monitor ModeUBS00HA8
Specification data are reference values.
On Board Diagnosis LogicUBS00HA9
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal fluctuates according to fuel feedback control.
DTC Confirmation ProcedureUBS00HAA
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1) ” or “A/F SEN1 (B2) ” in “DATA MONITOR” mode with CONSULT-II.
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
SEF579Z
SEF580Z
MONITOR ITEM CONDITIONSPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming up Maintaining engine speed at
2,000 rpm Fluctuates around 1.5V
DTC No. Trouble diagnosis name
DTC detecting conditionPossible Cause
P0130
0130
(Bank 1) Air fuel ratio (A/F) sensor 1
circuit

The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 1.5V.

Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)

Air fuel ratio (A/F) sensor 1
P0150
0150
(Bank 2)

EC-214Revision: November 2009
DTC P0130, P0150 A/F SENSOR 1
2006 QX56
If the indication is constantly approx. 1.5V and does not fluctuates, go to EC-219, "Diagnostic Procedure" .
If the indication fluctuates around 1.5V, go to next step.
4. Select “A/F SEN1 (B1) P1276 ” (for DTC P0130) or “A/F SEN1 (B2) P1286 ” (for DTC P0150) of “A/F
SEN1 ” in “DTC WORK SUPPORT ” mode with CONSULT-II.
5. Touch “START”.
6. When the following conditions are met, “TESTING” will be dis-
played on the CONSULT-II screen.
If “TESTING” is not displayed after 20 seconds, retry from
step 2.
7. Release accelerator pedal fully. NOTE:
Never apply brake during releasing the accelerator pedal.
8. Make sure that “TESTING ” changes to “COMPLETED ”.
If “TESTING” changed to “OUT OF CONDITION”, retry from
step 6.
9. Make sure that “OK” is displayed after touching “SELF-DIAG
RESULT ”.
If “NG ” is displayed, go to EC-219, "
Diagnostic Procedure" .
Overall Function CheckUBS00HAB
Use this procedure to check the overall function of the A/F sensor 1 circuit. During this check, a 1st trip DTC
might not be confirmed.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Drive the vehicle at a speed of 80 km/h (50 MPH) for a few minutes in the suitable gear position.
3. Set D position, then release the accelerator pedal fully until the vehicle speed decreases to 50 km/h (30
MPH).
NOTE:
Never apply brake during releasing the accelerator pedal.
4. Repeat steps 2 to 3 for five times.
5. Stop the vehicle and turn ignition switch OFF.
6. Wait at least 10 seconds and restart engine.
7. Repeat steps 2 to 3 for five times.
ENG SPEED 850 - 3,200 rpm
Vehicle speed More than 64 km/h (40 MPH)
B/FUEL SCHDL 1.0 - 8.0 msec
Selector lever D position
SEF576Z
SEF577Z
SEF578Z

DTC P0130, P0150 A/F SENSOR 1EC-217
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
2O/B A/F sensor 1 heater
(bank 1) [Engine is running]

Warm-up condition

Idle speed Approximately 5V
16 BR/R A/F sensor 1 (bank 1) [Engine is running]

Warm-up condition

Idle speed Approximately 3.1V
35 BR/G Approximately 2.6V
56 LG/B Approximately 2.3V
75 P/B Approximately 2.3V
PBIB1584E

DTC P0130, P0150 A/F SENSOR 1EC-219
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureUBS00HAD
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
24 BR/W A/F sensor 1 heater
(bank 2) [Engine is running]

Warm-up condition

Idle speed Approximately 5V
57 L/P A/F sensor 1 (bank 2) [Engine is running]

Warm-up condition

Idle speed Approximately 2.6V
58 GR/G Approximately 2.3V
76 G/L Approximately 3.1V
77 BR/B Approximately 2.3V
PBIB1584E
BBIA0354E

DTC P0131, P0151 A/F SENSOR 1EC-223
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
DTC P0131, P0151 A/F SENSOR 1PFP:22693
Component DescriptionUBS00H9F
The air fuel ratio (A/F) sensor 1 is a planar dual-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is the combination of a
Nernst concentration cell (sensor cell) with an oxygen-pump cell,
which transports ions. It has a heater in the element.
The sensor is capable of precise measurement = 1, but also in the
lean and rich range. Together with its control electronics, the sensor
outputs a clear, continuous signal throughout a wide range (0.7 <
< air).
The exhaust gas components diffuse through the diffusion gap at the
electrode of the oxygen pump and Nernst concentration cell, where
they are brought to thermodynamic balance.
An electronic circuit controls the pump current through the oxygen-
pump cell so that the composition of the exhaust gas in the diffusion
gap remains constant at = 1. Therefore, the A/F sensor 1 is able to
indicate air/fuel ratio by this pumping of current. In addition, a heater
is integrated in the sensor to ensure the required operating tempera-
ture of 700 - 800 °C (1,292 - 1,472 °F).
CONSULT-II Reference Value in Data Monitor ModeUBS00H9G
Specification data are reference values.
On Board Diagnosis LogicUBS00H9H
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal is not inordinately low.
DTC Confirmation ProcedureUBS00H9I
NOTE:
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
WITH CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1) ” or “A/F SEN1 (B2) ” in “DATA MONITOR” mode with CONSULT-II.
SEF579Z
SEF580Z
MONITOR ITEM CONDITIONSPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)

Engine: After warming up Maintaining engine speed at
2,000 rpm Fluctuates around 1.5V
DTC No. Trouble diagnosis name
DTC detecting conditionPossible Cause
P0131
0131
(Bank 1) Air fuel ratio (A/F) sensor 1
circuit low voltage

The A/F signal computed by ECM from the
A/F sensor 1 signal is constantly approx. 0V.

Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)

Air fuel ratio (A/F) sensor 1
P0151
0151
(Bank 2)