air condition INFINITI QX56 2009 Factory Service Manual
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![INFINITI QX56 2009 Factory Service Manual
EC-136
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P0130, P0150 A/F SENSOR 1
P0130, P0150 A/F SENSOR 1
Component DescriptionINFOID:0000000003771398
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit cu INFINITI QX56 2009 Factory Service Manual
EC-136
< COMPONENT DIAGNOSIS >[VK56DE]
P0130, P0150 A/F SENSOR 1
P0130, P0150 A/F SENSOR 1
Component DescriptionINFOID:0000000003771398
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit cu](/img/42/57031/w960_57031-1462.png)
EC-136
< COMPONENT DIAGNOSIS >[VK56DE]
P0130, P0150 A/F SENSOR 1
P0130, P0150 A/F SENSOR 1
Component DescriptionINFOID:0000000003771398
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the
A/F sensor 1 is composed an elec-
trode layer, 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.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of about 800 °C
(1,472 °F).
On Board Diagn osis LogicINFOID:0000000003771399
To judge the malfunction, the diagnosis checks that t he A/F signal computed by ECM from the A/F sensor 1
signal fluctuates according to fuel feedback control.
DTC Confirmation ProcedureINFOID:0000000003771400
Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
PROCEDURE FOR MALFUNCTION A
1. Start engine and warm it up to normal operating temperature.
2. Let engine idle for 2 minutes.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to EC-137, "Diagnosis Procedure"
.
PBIB3353E
PBIB3354E
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P0130
0130
(Bank 1) Air fuel ratio (A/F) sensor 1
circuit A)
The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly in the range other
than approx. 2.2V.
Harness or connectors
(The A/F sensor 1 circuit is open
or shorted.)
Air fuel ratio (A/F) sensor 1
P0150
0150
(Bank 2) B)
The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 2.2V.
Revision: December 20092009 QX56
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![INFINITI QX56 2009 Factory Service Manual
EC-140
< COMPONENT DIAGNOSIS >[VK56DE]
P0131, P0151 A/F SENSOR 1
P0131, P0151 A/F SENSOR 1
Component DescriptionINFOID:0000000003771403
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit cu INFINITI QX56 2009 Factory Service Manual
EC-140
< COMPONENT DIAGNOSIS >[VK56DE]
P0131, P0151 A/F SENSOR 1
P0131, P0151 A/F SENSOR 1
Component DescriptionINFOID:0000000003771403
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit cu](/img/42/57031/w960_57031-1466.png)
EC-140
< COMPONENT DIAGNOSIS >[VK56DE]
P0131, P0151 A/F SENSOR 1
P0131, P0151 A/F SENSOR 1
Component DescriptionINFOID:0000000003771403
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the
A/F sensor 1 is composed an elec-
trode layer, 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.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of about 800 °C
(1,472 °F).
On Board Diagn osis LogicINFOID:0000000003771404
To judge the malfunction, the diagnosis checks that t he A/F signal computed by ECM from the A/F sensor 1
signal is not inordinately low.
DTC Confirmation ProcedureINFOID:0000000003771405
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
1. Start engine and warm it up to normal operating temperature.
2. Select “A/F SEN1 (B1)” or “A/F SEN1 (B 2)” in “DATA MONITOR” mode with CONSULT-III.
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
If the indication is constantly approx. 0V, go to EC-141, "Diagnosis Procedure"
.
If the indication is not constantly approx. 0V, go to next step.
4. Turn ignition switch OFF, wait at least 10 seconds and then restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH) within 20 seconds after restarting engine.
6. Maintain the following conditions for about 20 consecutive seconds.
PBIB3353E
PBIB3354E
DTC No. Trouble diagnosis name DTC detecting condition Possible 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)
Revision: December 20092009 QX56
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P0132, P0152 A/F SENSOR 1EC-143
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P0132, P0152 A/F SENSOR 1
Component DescriptionINFOID:0000000003771407
The air fuel ratio (A/F) sensor INFINITI QX56 2009 Factory Service Manual
P0132, P0152 A/F SENSOR 1EC-143
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P0132, P0152 A/F SENSOR 1
Component DescriptionINFOID:0000000003771407
The air fuel ratio (A/F) sensor](/img/42/57031/w960_57031-1469.png)
P0132, P0152 A/F SENSOR 1EC-143
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P0132, P0152 A/F SENSOR 1
Component DescriptionINFOID:0000000003771407
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is composed an elec-
trode layer, which transports ions. It has a heater in the element.
The sensor is capable of precise m
easurement = 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.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of about 800 °C
(1,472 °F).
On Board Diagnosis LogicINFOID:0000000003771408
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 high.
DTC Confirmation ProcedureINFOID:0000000003771409
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10.5V at idle.
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-III.
3. Check “A/F SEN1 (B1)” or “A/F SEN1 (B2)” indication.
If the indication is constantly approx. 5V, go to EC-144, "Diagnosis Procedure"
.
If the indication is not constantly approx. 5V, go to next step.
4. Turn ignition switch OFF, wait at least 10 seconds and then restart engine.
5. Drive and accelerate vehicle to more than 40 km/h (25 MPH) within 20 seconds after restarting engine.
6. Maintain the following conditions for about 20 consecutive seconds.
PBIB3353E
PBIB3354E
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P0132
0132
(Bank 1) Air fuel ratio (A/F) sensor 1
circuit high voltage The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 5V. Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
Air fuel ratio (A/F) sensor 1
P0132
0132
(Bank 2)
Revision: December 20092009 QX56
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![INFINITI QX56 2009 Factory Service Manual
EC-146
< COMPONENT DIAGNOSIS >[VK56DE]
P0133, P0153 A/F SENSOR 1
P0133, P0153 A/F SENSOR 1
Component DescriptionINFOID:0000000003771411
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit cu INFINITI QX56 2009 Factory Service Manual
EC-146
< COMPONENT DIAGNOSIS >[VK56DE]
P0133, P0153 A/F SENSOR 1
P0133, P0153 A/F SENSOR 1
Component DescriptionINFOID:0000000003771411
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit cu](/img/42/57031/w960_57031-1472.png)
EC-146
< COMPONENT DIAGNOSIS >[VK56DE]
P0133, P0153 A/F SENSOR 1
P0133, P0153 A/F SENSOR 1
Component DescriptionINFOID:0000000003771411
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the
A/F sensor 1 is composed an elec-
trode layer, 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.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of about 800 °C
(1,472 °F).
On Board Diagn osis LogicINFOID:0000000003771412
To judge the malfunction of A/F sensor 1, this diagnosis measures response time of the A/F signal computed
by ECM from the A/F sensor 1 signal. The time is compensated by engine operating (speed and load), fuel
feedback control constant, and the A/F sensor 1 temper ature index. Judgment is based on whether the com-
pensated time (the A/F signal cycling time index) is inordinately long or not.
DTC Confirmation ProcedureINFOID:0000000003771413
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
WITH CONSULT-III
PBIB3353E
PBIB3354E
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P0133
0133
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit slow response The response of the A/F signal computed by
ECM from A/F sensor 1 signal takes more than
the specified time. Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
A/F sensor 1
A/F sensor 1 heater
Fuel pressure
Fuel injector
Intake air leaks
Exhaust gas leaks
PCV
Mass air flow sensor
P0153
0153
(Bank 2)
Revision: December 20092009 QX56
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P0133, P0153 A/F SENSOR 1EC-147
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1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait a INFINITI QX56 2009 Factory Service Manual
P0133, P0153 A/F SENSOR 1EC-147
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1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait a](/img/42/57031/w960_57031-1473.png)
P0133, P0153 A/F SENSOR 1EC-147
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1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
4. Let engine idle for 1 minute.
5. Select “A/F SEN1(B1) P1278/P1279”
(for DTC P0133) or “A/F SEN1(B2) P1288/P1289” (for DTC P0153)
of “A/F SEN1” in “DTC WORK SUPPORT” mode with CONSULT-III.
6. Touch “START”. If “COMPLETED” appears on CONSULT-III screen, go to step 10.
If “COMPLETED” does not appear on CONSULT- III screen, go to the following step.
7. After perform the following procedure, “TESTIN G” will be displayed on the CONSULT-III screen.
a. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
b. Fully release accelerator pedal and then let engine idle for about 10 seconds. If “TESTING” is not displayed after 10 seconds, refer to EC-74
.
8. Wait for about 20 seconds at idle under the conditi on that “TESTING” is displayed on the CONSULT-III
screen.
9. Make sure that “TESTING” changes to “COMPLETED”. If “TESTING” changed to “OUT OF CONDITION”, refer to EC-74
.
10. Make sure that “OK” is display ed after touching “SELF-DIAG RESULT”.
If “NG” is displayed, go to EC-147, "Diagnosis Procedure"
.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Select Service $01 with GST.
3. Calculate the total value of “Short term f uel trim” and “Long term fuel trim” indications.
Make sure that the total percentage should be within ±15%.
If OK, go to the following step.
If NG, check the following.
Intake air leaks
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Fuel injector
Incorrect PCV hose connection
PCV valve
Mass air flow sensor
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1minute under no load.
6. Let engine idle for 1 minute.
7. Increase the engine speed up to 4,000 to 5,000 rpm and keep it for 10 seconds.
8. Fully release accelerator pedal and then let engine idle for about 1 minute.
9. Select Service $07 with GST. If the 1st trip DTC is displayed, go to EC-147, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771414
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Revision: December 20092009 QX56
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EC-152
< COMPONENT DIAGNOSIS >[VK56DE]
P0137, P0157 HO2S2
P0137, P0157 HO2S2
Component DescriptionINFOID:0000000003771415
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the INFINITI QX56 2009 Factory Service Manual
EC-152
< COMPONENT DIAGNOSIS >[VK56DE]
P0137, P0157 HO2S2
P0137, P0157 HO2S2
Component DescriptionINFOID:0000000003771415
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the](/img/42/57031/w960_57031-1478.png)
EC-152
< COMPONENT DIAGNOSIS >[VK56DE]
P0137, P0157 HO2S2
P0137, P0157 HO2S2
Component DescriptionINFOID:0000000003771415
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of
the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is cont rolled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated ox ygen sensor 2 is not used for
engine control operation.
On Board Diagn osis LogicINFOID:0000000003771416
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the air fuel ratio (A/F) sensor 1. The oxy-
gen storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the maximum voltage of the sensor
is sufficiently high during the various driving condition such as fuel-
cut.
DTC Confirmation ProcedureINFOID:0000000003771417
NOTE:
If DTC confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
WITH CONSULT-III
TESTING CONDITION:
For better results, perform “DTC WORK SU PPORT” at a temperature of 0 to 30 °C (32 to 86 °F).
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70 °C (158 °F).
SEF327R
PBIB1154E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0137
0137
(Bank 1) Heated oxygen sensor 2
circuit low voltage The maximum voltage from the sensor is not
reached to the specified voltage. Harness or connectors
(The sensor circuit is open or shorted)
Heated oxygen sensor 2
Fuel pressure
Fuel injector
Intake air leaks
P0157
0157
(Bank 2)
Revision: December 20092009 QX56
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P0138, P0158 HO2S2EC-157
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P0138, P0158 HO2S2
Component DescriptionINFOID:0000000003771421
The heated oxygen sensor 2, after three way c INFINITI QX56 2009 Factory Service Manual
P0138, P0158 HO2S2EC-157
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P0138, P0158 HO2S2
Component DescriptionINFOID:0000000003771421
The heated oxygen sensor 2, after three way c](/img/42/57031/w960_57031-1483.png)
P0138, P0158 HO2S2EC-157
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P0138, P0158 HO2S2
Component DescriptionINFOID:0000000003771421
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
On Board Diagnosis LogicINFOID:0000000003771422
The heated oxygen sensor 2 has a much longer switching
time between rich and lean than the air fuel ratio (A/
F) sensor 1. The oxygen storage capacity of the thr ee way catalyst (manifold) causes the longer switching
time.
MALFUNCTION A
To judge the malfunctions of heated oxygen sensor 2, ECM monitors
whether the voltage is unusually high during the various driving con-
dition such as fuel-cut.
MALFUNCTION B
To judge the malfunctions of heated oxygen sensor 2, ECM monitors
whether the minimum voltage of sensor is sufficiently low during the
various driving condition such as fuel-cut.
DTC Confirmation ProcedureINFOID:0000000003771423
Perform PROCEDURE FOR MALFUNCTION A first.
SEF327R
PBIB1848E
PBIB2376E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0138
0138
(Bank 1) Heated oxygen sensor 2
circuit high voltage A)
An excessively high voltage from the sen-
sor is sent to ECM. Harness or connectors
(The sensor circuit is open or shorted)
Heated oxygen sensor 2
P0158
0158
(Bank 2) B)
The minimum voltage from the sensor is
not reached to the specified voltage. Harness or connectors
(The sensor circuit is open or shorted)
Heated oxygen sensor 2
Fuel pressure
Fuel injector
Revision: December 20092009 QX56
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EC-164
< COMPONENT DIAGNOSIS >[VK56DE]
P0139, P0159 HO2S2
P0139, P0159 HO2S2
Component DescriptionINFOID:0000000003771427
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the INFINITI QX56 2009 Factory Service Manual
EC-164
< COMPONENT DIAGNOSIS >[VK56DE]
P0139, P0159 HO2S2
P0139, P0159 HO2S2
Component DescriptionINFOID:0000000003771427
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the](/img/42/57031/w960_57031-1490.png)
EC-164
< COMPONENT DIAGNOSIS >[VK56DE]
P0139, P0159 HO2S2
P0139, P0159 HO2S2
Component DescriptionINFOID:0000000003771427
The heated oxygen sensor 2, after three way catalyst (manifold),
monitors the oxygen level in the exhaust gas on each bank.
Even if switching characteristics of
the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is cont rolled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated ox ygen sensor 2 is not used for
engine control operation.
On Board Diagn osis LogicINFOID:0000000003771428
The heated oxygen sensor 2 has a much longer switching time
between rich and lean than the air fuel ratio (A/F) sensor 1. The oxy-
gen storage capacity of the three way catalyst (manifold) causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the switching response of the sen-
sor's voltage is faster than specified during the various driving condi-
tion such as fuel-cut.
DTC Confirmation ProcedureINFOID:0000000003771429
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
WITH CONSULT-III
TESTING CONDITION:
For better results, perform “DTC WORK SU PPORT” at a temperature of 0 to 30 °C (32 to 86 °F).
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. Make sure that “COOLAN TEMP/S” indicates more than 70 °C (158 °F).
SEF327R
SEF302U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0139
0139
(Bank 1) Heated oxygen sensor 2
circuit slow response It takes more time for the sensor to respond be-
tween rich and lean than the specified time. Harness or connectors
(The sensor circuit is open or shorted)
Heated oxygen sensor 2
Fuel pressure
Fuel injector
Intake air leaks
P0159
0159
(Bank 2)
Revision: December 20092009 QX56
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P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-169
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P0171, P0174 FUEL INJE
CTION SYSTEM FUNCTION
On Board Diagnosis LogicINFOID:0000000 INFINITI QX56 2009 Factory Service Manual
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-169
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P0171, P0174 FUEL INJE
CTION SYSTEM FUNCTION
On Board Diagnosis LogicINFOID:0000000](/img/42/57031/w960_57031-1495.png)
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
EC-169
< COMPONENT DIAGNOSIS > [VK56DE]
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P0171, P0174 FUEL INJE
CTION SYSTEM FUNCTION
On Board Diagnosis LogicINFOID:0000000003771433
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio f eedback signal from the A/F sensors 1. The ECM calcu-
lates the necessary compensation to correct the of fset between the actual and the theoretical ratios.
In case the amount of the compensation value is extrem ely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC Confirmation ProcedureINFOID:0000000003771434
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
WITH CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON and select “SELF-LEARNING CONT” in “WORK SUPPORT” mode with CON-
SULT-III.
4. Clear the self-learning control coefficient by touching “CLEAR”.
5. Start engine again and let it idle for at least 10 minutes.
6. Check 1st trip DTC. The 1st trip DTC P0171 or P0174 should be detected at this stage, if a malfunction exists. If so, go to EC-
170, "Diagnosis Procedure".
NOTE:
If 1st trip DTC is not detected during above proc edure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar condi tions to (1st trip) Freeze Frame Data for 10 min-
utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
Sensor Input signal to ECM ECM function Actuator
A/F sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal)
Fuel injection control Fuel injector
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0171
0171
(Bank 1) Fuel injection system too
lean Fuel injection system does not operate properly.
The amount of mixture ratio compensation is too
large. (The mixture ratio is too lean.) Intake air leaks
A/F sensor 1
Fuel injector
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Mass air flow sensor
Incorrect PCV hose connection
P0174
0174
(Bank 2)
Engine speed Engine speed in the freeze frame data
± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Revision: December 20092009 QX56
Page 1497 of 4171
![INFINITI QX56 2009 Factory Service Manual
EC-170
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
7. If it is difficult to start engine at step 6,
the fuel injection system has a malfunction, too.
8. Crank engine INFINITI QX56 2009 Factory Service Manual
EC-170
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
7. If it is difficult to start engine at step 6,
the fuel injection system has a malfunction, too.
8. Crank engine](/img/42/57031/w960_57031-1496.png)
EC-170
< COMPONENT DIAGNOSIS >[VK56DE]
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION
7. If it is difficult to start engine at step 6,
the fuel injection system has a malfunction, too.
8. Crank engine while depressing accelerator pedal. If engine starts, go to EC-170, "Diagnosis Procedure"
. If
engine does not start, check exhaust and intake air leak visually.
WITH GST
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Disconnect mass air flow sensor harness connector.
4. Restart engine and let it idle for at least 5 seconds.
5. Stop engine and reconnect mass air flow sensor harness con- nector.
6. Select Service $03 with GST. Make sure DTC P0102 is detected.
7. Select Service $04 with GST and erase the DTC P0102.
8. Start engine again and let it idle for at least 10 minutes.
9. Select Service $07 with GST. The 1st trip DTC P0171 or P0174 should be detected at this stage, if a malfunction exists. If so, go
to EC-170, "Diagnosis Procedure"
.
NOTE:
If 1st trip DTC is not detected during above proc edure, performing the following procedure is advised.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Start engine and drive the vehicle under the similar conditions to (1st trip) Freeze Frame Data for 10 min- utes. Refer to the table below.
Hold the accelerator pedal as steady as possible.
The similar conditions to (1st trip) Freeze Frame Da ta means the vehicle operation that the following con-
ditions should be satisfied at the same time.
10. If it is difficult to start engine at step 8, the fuel injection system has a malfunction.
11. Crank engine while depressing accelerator pedal. If engine starts, go to EC-170, "Diagnosis Procedure"
.
If engine does not start, check exhaus t and intake air leak visually.
Diagnosis ProcedureINFOID:0000000003771435
1.CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
Engine coolant temperature (T)
condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
BBIA0368E
Engine speed Engine speed in the freeze frame data ± 400 rpm
Vehicle speed Vehicle speed in the freeze frame data ± 10 km/h (6 MPH)
Engine coolant temperature (T)
condition When the freeze frame data shows lower than 70
°C (158 °F),
T should be lower than 70 °C (158 °F).
When the freeze frame data shows higher than or equal to 70 °C (158 °F),
T should be higher than or equal to 70 °C (158 °F).
Revision: December 20092009 QX56