ground INFINITI QX56 2011 Factory Service Manual

P0131, P0151 A/F SENSOR 1EC-233
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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If this procedure is not completed within 1 minute after restarting engine at step 1, return to step
1.
7. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Go to EC-233, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217808
1.CHECK AIR FUEL RATIO SENSO R 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 2.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
2.CHECK A/F SENSOR 1 INPUT SIGNAL 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.
5. Also check harness for 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 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.
DTCA/F sensor 1
Ground Voltage
Bank Connector Terminal
P0130 1 F67 4 Ground 3.0 V
P0150 2 F68 4
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0130 1 F67 3 F11088
Existed
P0150 2 F68 3 78
DTC A/F sensor 1 ECM
Ground Continuity
Bank Connector Terminal Connector Terminal
P0130 1 F67 3 F11088
Ground Not existed
P0150 2 F68 3 78
Revision: 2010 May2011 QX56

EC-234
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0131, P0151 A/F SENSOR 1
4. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK INTERMITTENT INCIDENT
Perform GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace malfunctioning part.
5.REPLACE A/F SENSOR 1
Replace malfunctioning A/F sensor 1. Refer to EM-40, "
Removal and Installation".
CAUTION:
 Discard any A/F sensor which has b een 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.
 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
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0130 1 F67 6 F11094
Existed
P0150 2 F68 6 74
Revision: 2010 May2011 QX56

EC-236
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0132, P0152 A/F SENSOR 1

If this procedure is not completed within 1 minute af ter restarting engine at step 1, return to step
1.
7. Check 1st trip DTC.
WITH GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Go to EC-236, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217810
1.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 2.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
2.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.
5. Also check harness for 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 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.
DTCA/F sensor 1
Ground Voltage
Bank Connector Terminal
P0130 1 F67 4 Ground 3.0 V
P0150 2 F68 4
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0130 1 F67 3 F11088
Existed
P0150 2 F68 3 78
DTC A/F sensor 1 ECM
Ground Continuity
Bank Connector Terminal Connector Terminal
P0130 1 F67 3 F11088
Ground Not existed
P0150 2 F68 3 78
Revision: 2010 May2011 QX56

P0132, P0152 A/F SENSOR 1EC-237
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4. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK INTERMITTENT INCIDENT
Perform GI-40, "
Intermittent Incident".
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair or replace malfunctioning part.
5.REPLACE A/F SENSOR 1
Replace malfunctioning A/F sensor 1. Refer to EM-40, "
Removal and Installation".
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.
 Before installing new A/F senso r, clean exhaust 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
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0130 1 F67 6 F11094
Existed
P0150 2 F68 6 74
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
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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

P0137, P0157 HO2S2EC-245
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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

EC-246
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0137, P0157 HO2S2
3. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK HEATED OXYGEN SENSOR 2
Refer to EC-246, "
Component Inspection (HO2 sensor 2)".
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.REPLACE HEATED OXYGEN SENSOR 2
Replace malfunctioning heated oxygen sensor 2. Refer to EM-40, "
Exploded View".
CAUTION:
 Discard any heated oxygen 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.
 Before installing new oxygen sensor, clean exh aust 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
6.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (HO2 sensor 2)INFOID:0000000006217816
1.INSPECTION START
Will CONSULT-III be used?
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 3.
2.CHECK HEATED OXYGEN SENSOR 2
With CONSULT-III
1. Start engine and warm it up to the normal operating temperature.
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. Select “FUEL INJECTION” in “ACT IVE TEST” mode, and select “HO2S2 (B1)/(B2)” as the monitor item
with CONSULT-III.
5. Check “HO2S2 (B1)/(B2)” at idle speed when adjusting “FUEL INJECTION” to ±25%.
“HO2S2 (B1)/(B2)” should be above 0.74 V at least once when the “FUEL INJECTION” is +25%.
“HO2S2 (B1)/(B2)” should be below 0.18 V at least once when the “FUEL INJECTION” is −25%.
Is the inspection result normal?
YES >> INSPECTION END
JMBIA1573GB
Revision: 2010 May2011 QX56

EC-252
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0138, P0158 HO2S2
Which malfunction is detected?
A>>GO TO 2
B>>GO TO 8.
2.CHECK HEATED OXYGEN SENSOR 2 CONNECTOR
1. Disconnect heated oxygen sensor 2 (HO2S2) harness connector.
2. Check that water is not inside connectors.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair or replace harness or connectors.
3.CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check the continuity between HO2S2 harness connector and ECM harness connector.
3. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
4.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.
3. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
5.CHECK HEATED OXYGEN SENSOR 2
Refer to EC-254, "
Component Inspection (HO2 sensor 2)".
Is the inspection result normal?
YES >> GO TO 7.
NO >> GO TO 6.
6.REPLACE HEATED OXYGEN SENSOR 2
Replace malfunctioning heated oxygen sensor 2. Refer to EM-40, "
Exploded View".
CAUTION:
DTC HO2S2 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0138 1 F87 1 F110 100 Existed
P0158 2 F88 1
DTC HO2S2 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0138 1 F87 4 F11096
Existed
P0158 2 F88 4 87
DTC HO2S2 ECM
Ground Continuity
Bank Connector Terminal Connector Terminal
P0138 1 F87 4 F11096
Ground Not existed
P0158 2 F88 4 87
Revision: 2010 May2011 QX56

P0138, P0158 HO2S2EC-253
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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 Discard any heated oxygen sensor which has been dr
opped 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.
 Before installing new oxygen sensor, clean exh aust 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
7.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
8.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 P0172 or P0175 detected? Is it difficult to start engine?
YES >> Perform trouble diagnosis for DTC P0172, P0175. Refer to EC-267, "DTC Logic".
NO >> GO TO 9.
9.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 10.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
10.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.
3. Also check harness for short to power.
Is the inspection result normal?
YES >> GO TO 11.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
DTC HO2S2 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0138 1 F87 1 F110 100 Existed
P0158 2 F88 1
DTC HO2S2 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0138 1 F87 4 F11096
Existed
P0158 2 F88 4 87
DTC HO2S2 ECM
Ground Continuity
Bank Connector Terminal Connector Terminal
P0138 1 F87 4 F11096
Ground Not existed
P0158 2 F88 4 87
Revision: 2010 May2011 QX56