INFINITI QX56 2006 Factory Service Manual

EC-240Revision: November 2009
DTC P0132, P0152 A/F SENSOR 1
2006 QX56
Removal and InstallationUBS00H9S
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-21, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .

DTC P0133, P0153 A/F SENSOR 1EC-241
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Revision: November 2009 2006 QX56
DTC P0133, P0153 A/F SENSOR 1PFP:22693
Component DescriptionUBS00N6R
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 ModeUBS00N6S
Specification data are reference values.
On Board Diagnosis LogicUBS00N6T
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 temperature index. Judgment is based on whether the com-
pensated time (the A/F signal cycling time index) is inordinately long or not.
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 1.5 V
DTC No. Trouble diagnosis name DTC detecting conditionPossible 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)

EC-242Revision: November 2009
DTC P0133, P0153 A/F SENSOR 1
2006 QX56
DTC Confirmation ProcedureUBS00N6U
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. 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(B1) P1288/P1289 ” (for DTC P0153)
of “A/F SEN1 ” in “DTC WORK SUPPORT ” mode with CONSULT-II.
6. Touch “START”.
If “COMPLETED” appears on CONSULT-II screen, go to step
10.
If “COMPLETED ” does not appear on CONSULT-II screen, go to
the following step.
7. After perform the following procedure, “TESTING ” will be dis-
played on the CONSULT-II 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-
134, "TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
8. Wait for about 20 seconds at idle at under the condition that “TESTING ” is displayed on the CONSULT-II screen.
9. Make sure that “TESTING ” changes to “COMPLETED ”.
If “TESTING” changed to “OUT OF CONDITION”, refer to
EC-134, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
10. Make sure that “OK” is displayed after touching “SELF-DIAG
RESULT ”.
If “NG ” is displayed, go to EC-247, "
Diagnostic 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 fuel 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.
PBIB0756E
PBIB1925E
PBIB0758E

DTC P0133, P0153 A/F SENSOR 1EC-243
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Revision: November 2009 2006 QX56

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-247, "
Diagnostic Procedure" .

EC-244Revision: November 2009
DTC P0133, P0153 A/F SENSOR 1
2006 QX56
Wiring DiagramUBS00N6V
BANK 1
BBWA2111E

DTC P0133, P0153 A/F SENSOR 1EC-245
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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

EC-246Revision: November 2009
DTC P0133, P0153 A/F SENSOR 1
2006 QX56
BANK 2
BBWA2112E

DTC P0133, P0153 A/F SENSOR 1EC-247
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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 ProcedureUBS00N6W
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

EC-248Revision: November 2009
DTC P0133, P0153 A/F SENSOR 1
2006 QX56
2. RETIGHTEN A/F SENSOR 1
Loosen and retighten the A/F sensor 1.
>> GO TO 3.
3. CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
OK or NG
OK >> GO TO 4.
NG >> Repair or replace.
4. CHECK FOR INTAKE AIR LEAK
Listen for an intake air leak after the mass air flow sensor.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace. Tightening torque: 50 N-m (5.1 kg-m, 37 ft-lb)
BBIA0375E
PBIB1216E

DTC P0133, P0153 A/F SENSOR 1EC-249
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Revision: November 2009 2006 QX56
5. CLEAR THE SELF-LEARNING DATA
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select “SELF-LEARNING CONT ” in “WORK SUPPORT ” mode with CONSULT-II.
3. Clear the self-learning control coefficient by touching “CLEAR” or “START ”.
4. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171, P172, P0174 or P0175 detected?
Is it difficult to start engine?
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF.
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. Make sure DTC P0102 is displayed.
7. Erase the DTC memory. Refer to EC-61, "
HOW TO ERASE
EMISSION-RELATED DIAGNOSTIC INFORMATION" .
8. Make sure DTC P0000 is displayed.
9. Run engine for at least 10 minutes at idle speed. Is the 1st trip DTC P0171, P0172, P0174 or P0175 detected?
Is it difficult to start engine?
Ye s o r N o
Yes >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-288, "DTC
P0171, P0174 FUEL INJECTION SYSTEM FUNCTION" or EC-299, "DTC P0172, P0175 FUEL
INJECTION SYSTEM FUNCTION" .
No >> GO TO 6.
SEF968Y
BBIA0368E