2011 INFINITI QX56 sensor

EC-238
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0133, P0153 A/F SENSOR 1
P0133, P0153 A/F SENSOR 1
DTC LogicINFOID:0000000006217811
DTC DETECTION LOGIC
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 PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 11 V or more at idle.
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 5.
2.PERFORM DTC CONFIRMATION PROCEDURE-I
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.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Restart engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6. Let engine idle for 1 minute.
7. Select “A/F SEN1(B1) P1278/P1279” (for DTC P 0133) or “A/F SEN1(B2) P1288/P1289” (for DTC P0153)
of “A/F SEN1” in “DTC WORK SUPPORT” mode with CONSULT-III.
8. Touch “START”.
Is
“COMPLETED” displayed on CONSULT-III screen?
YES >> GO TO 3
NO >> GO TO 4.
3.PERFORM DTC CONFIRMATION PROCEDURE-II
Touch “SELF-DIAG RESULT”.
Which is displayed on CONSULT-III screen?
OK >> INSPECTION END
NG >> Go to EC-239, "
Diagnosis Procedure".
4.PERFORM DTC CONFIRMATION PROCEDURE-II
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible Cause
P0133 A/F SENSOR1 (B1)
[Air fuel ratio (A/F) sensor 1
(bank 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
A/F SENSOR1 (B2)
[Air fuel ratio (A/F) sensor 1
(bank 2) circuit slow response]
Revision: 2010 May2011 QX56

P0133, P0153 A/F SENSOR 1EC-239
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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1. After perform the following procedure, “TESTIN
G” will be displayed on the CONSULT-III screen.
- Increase the engine speed up to between 4,000 and 5,000 rpm and maintain that speed for 10 seconds.
- Fully release accelerator pedal and then let engine idle for approximately 10 seconds. If “TESTING” is not displayed after 10 seconds, refer to EC-161, "
Component Function Check".
2. Wait for approximately 20 seconds at idle under t he condition that “TESTING” is displayed on the CON-
SULT-III screen.
3. Check that “TESTING” changes to “COMPLETED”. If “TESTING” changed to “OUT OF CONDITION”, refer to EC-161, "
Component Function Check".
4. Touch “SELF-DIAG RESULT”.
Which is displayed on CONSULT-III screen?
OK >> INSPECTION END
NG >> Go to EC-239, "
Diagnosis Procedure".
5.CHECK AIR-FUEL RATIO SELF-LEARNING VALUE
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.
Is the total percentage within
±15%?
YES >> GO TO 7.
NO >> GO TO 6.
6.DETECT MALFUNCTIONING PART
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
>> Repair or replace malfunctioning part.
7.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
3. Let engine idle for 1 minute.
4. Increase the engine speed up to between 4,000 and 5,000 rpm and maintain that speed for 10 seconds.
5. Fully release accelerator pedal and then let engine idle for approximately 1 minute.
6. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-239, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217812
1.RETIGHTEN AIR FUEL RATIO SENSOR 1
Loosen and retighten the air fuel rati o (A/F) sensor 1. Refer to EM-40, "
Exploded View".
>> GO TO 2.
2.CHECK EXHAUST GAS LEAKAGE
1. Start engine and run it at idle.
Revision: 2010 May2011 QX56

EC-240
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0133, P0153 A/F SENSOR 1
2. Listen for an exhaust gas leakage before three way catalyst (manifold).
Is exhaust gas leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 3.
3.CHECK FOR INTAKE AIR LEAKAGE
Listen for an intake air leakage after the mass air flow sensor.
Is intake air leakage detected?
YES >> Repair or replace malfunctioning part.
NO >> GO TO 4.
4.CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE
1. Clear the mixture ratio self-learning value. Refer to EC-152, "
Work Procedure".
2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171, P172, P0174 or P 0175 detected? Is it difficult to start engine?
YES >> Perform trouble diagnosis for DTC P0171, P0174 or P0172, P0175. Refer to EC-263, "DTC Logic"
or EC-267, "DTC Logic".
NO >> GO TO 5.
5.CHECK AIR FUEL RATIO SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
2. Turn ignition switch ON.
3. Check the voltage between A/F sensor 1 harness connector and ground.
Is the inspection result normal?
YES >> GO TO 6.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
6.CHECK A/F SENSOR 1 INPUT SIGN AL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
4. Check the continuity between A/F sensor 1 harness connector and ground, or ECM harness connector
and ground.
PBIB1216E
DTC A/F sensor 1
Ground Voltage
Bank Connector Terminal
P0133 1 F67 4 Ground 3.0 V
P0153 2 F68 4
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0133 1 F67 3 F11088
Existed
P0153 2 F68 3 78
Revision: 2010 May2011 QX56

P0133, P0153 A/F SENSOR 1EC-241
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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5. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 7.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK A/F SENSOR 1 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between A/F sensor 1 harness connector and ECM harness connector.
4. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 8.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
8.CHECK A/F SENSOR 1 HEATER
Refer to EC-182, "
Component Inspection (A/F Sensor 1 Heater)".
Is the inspection result normal?
YES >> GO TO 9.
NO >> GO TO 12.
9.CHECK MASS AIR FLOW SENSOR
Check mass air flow sensor.
Refer to EC-190, "
Component Inspection (MAF Sensor)".
Is the inspection result normal?
YES >> GO TO 10.
NO >> Replace malfunctioning mass air flow sensor. Refer to EM-30, "
Removal and Installation".
10.CHECK PCV VALVE
Refer to EC-534, "
Inspection".
Is the inspection result normal?
YES >> GO TO 11.
NO >> Repair or replace PCV valve.
11 .CHECK INTERMITTENT INCIDENT
Perform GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> GO TO 12.
NO >> Repair or replace malfunctioning part.
12.REPLACE A/F SENSOR 1
Replace malfunctioning A/F sensor 1. Refer to EM-40, "
Exploded View".
CAUTION:
 Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a
hard surface such as a concrete floor; use a new one.
DTC A/F sensor 1 ECM
Ground Continuity
Bank Connector Terminal Connector Terminal
P0133 1 F67 3 F11088
Ground Not existed
P0153 2 F68 3 78
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0133 1 F67 6 F 11194
Existed
P0153 2 F68 6 74
Revision: 2010 May2011 QX56

EC-242
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0133, P0153 A/F SENSOR 1
 Before installing new A/F sensor, clean exhau
st system threads using Oxygen Sensor Thread
Cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant
(commercial service tool).
>> INSPECTION END
Revision: 2010 May2011 QX56

P0137, P0157 HO2S2EC-243
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0137, P0157 HO2S2
DTC LogicINFOID:0000000006217813
DTC DETECTION LOGIC
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 various driving conditions such as fuel cut.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 4.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
TESTING CONDITION:
For better results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30 °C (32 to 86 °F).
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Restart engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6. Let engine idle for 1 minute.
7. Select “DATA MONITOR” mode with CONSULT-III.
8. Check that “COOLAN TEMP/S” indicates more than 70 °C (158 °F).
If not, warm up engine and go to next step w hen “COOLAN TEMP/S” indication reaches 70 °C (158 °F).
9. Open engine hood.
10. Select “HO2S2 (B1) P1147” (for DTC P0137) or “HO2S2 (B2) P1167” (for DTC P0157) of “HO2S2” in
“DTC WORK SUPPORT” mode with CONSULT-III.
11. Follow the instruction of CONSULT-III display.
NOTE:
It will take at most 10 minutes until “COMPLETED” is displayed.
12. Touch “SELF-DIAG RESULTS”.
JMBIA1572GB
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0137 HO2S2 (B1)
[Heated oxygen sensor 2
(bank 1) circuit low voltage]
The maximum voltage from the sensor does
not reach the specified voltage.  Harness or connectors
(The heated oxygen sensor 2 circuit is
open or shorted)
 Heated oxygen sensor 2
 Fuel pressure
 Fuel injector
 Intake air leaks
P0157
HO2S2 (B2)
[Heated oxygen sensor 2
(bank 2) circuit low voltage]
Revision: 2010 May2011 QX56

EC-244
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0137, P0157 HO2S2
Which is displayed on CONSULT-III screen?
OK >> INSPECTION END
NG >> Go to
EC-245, "
Diagnosis Procedure".
CAN NOT BE DIAGNOSED>>GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE AGAIN
1. Turn ignition switch OFF and leave the vehi cle in a cool place (soak the vehicle).
2. Perform DTC confirmation procedure again.
>> GO TO 2.
4.PERFORM COMPONENT FUNCTION CHECK
WITH GST
Perform component function check. Refer to EC-244, "
Component Function Check".
NOTE:
Use component function check to check the overall func tion of the heated oxygen sensor 2 circuit. During this
check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-245, "
Diagnosis Procedure".
Component Function CheckINFOID:0000000006217814
1.PERFORM COMPONENT FUNCTION CHECK-I
WITH GST
1. Start engine and warm it up to the normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Turn ignition switch ON.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Restart engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
6. Let engine idle for 1 minute.
7. Check the voltage between ECM harness connector terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.PERFORM COMPONENT FUNCTION CHECK-II
Check the voltage between ECM harness connector terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 3.
DTC ECM
Condition Voltage
Connector +–
Terminal Terminal
P0137 F110 96
100Revving up to 4,000 rpm under no load at
least 10 times The voltage should be above 0.74 V at
least once during this procedure.
P0157 87
DTC ECM
Condition Voltage
Connector +–
Terminal Terminal
P0137 F110 96
100 Keeping engine at idle for 10 minutes The voltage should be above 0.74 V at
least once during this procedure.
P0157 87
Revision: 2010 May2011 QX56

P0137, P0157 HO2S2EC-245
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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3.PERFORM COMPONENT FUNCTION CHECK-III
Check the voltage between ECM harness connector terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-245, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217815
1.CLEAR THE MIXTURE RATIO SELF-LEARNING VALUE
1. Clear the mixture ratio self-learning value. Refer to EC-152, "
Work Procedure".
2. Run engine for at least 10 minutes at idle speed.
Is the 1st trip DTC P0171 or P0174 detected? Is it difficult to start engine?
YES >> Perform trouble diagnosis for DTC P0171 or P0174. Refer to EC-263, "DTC Logic".
NO >> GO TO 2.
2.CHECK HEATED OXYGEN SENSOR 2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 (HO2S2) harness connector.
3. Disconnect ECM harness connector.
4. Check the continuity between HO2S2 harness connector and ECM harness connector.
5. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between HO2S2 harness connector and ECM harness connector.
2. Check the continuity between HO2S2 harness connector and ground, or ECM harness connector and
ground.
DTC ECM
Condition Voltage
Connector +–
Terminal Terminal
P0137 F110 96
100Coasting from 80 km/h (50 MPH) with se-
lector lever in the D position The voltage should be above 0.74 V at
least once during this procedure.
P0157 87
DTC HO2S2 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0137 1 F87 1 F110 100 Existed
P0157 2 F88 1
DTC HO2S2 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0137 1 F87 4 F11096
Existed
P0157 2 F88 4 87
DTC HO2S2 ECM
Ground Continuity
Bank Connector Terminal Connector Terminal
P0137 1 F87 4 F11096
Ground Not existed
P0157 2 F88 4 87
Revision: 2010 May2011 QX56