ignition INFINITI QX56 2011 Factory Service Manual

P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-181
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P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
DTC LogicINFOID:0000000006217775
DTC DETECTION LOGIC
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.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-181, "Diagnosis Procedure".
NG >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217776
1.CHECK AIR FUEL RATIO (A/F) 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 3.
NO >> GO TO 2.
DTC No. Trouble diagnosis
(Trouble diagnosis content) DTC detecting condition Possible cause
P0031 A/F SEN1 HTR (B1)
[A/F sensor 1 heater (bank
1) control circuit low] The current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the A/F sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
 A/F sensor 1 heater
P0032 A/F SEN1 HTR (B1)
[A/F sensor 1 heater (bank
1) control circuit high] The current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the A/F sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
 A/F sensor 1 heater
P0051 A/F SEN1 HTR (B2)
[A/F sensor 1 heater (bank
2) control circuit low] The current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the A/F sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
 A/F sensor 1 heater
P0052 A/F SEN1 HTR (B2)
[A/F sensor 1 heater (bank
2) control circuit high] The current amperage in the A/F sensor 1 heater
circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the A/F sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
 A/F sensor 1 heater
DTC A/F sensor 1
Ground Voltage
Bank Connector Terminal
P0031, P0032 1 F67 5 Ground Battery voltage
P0051, P0052 2 F68 5
Revision: 2010 May2011 QX56

EC-182
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0031, P0032, P0051, P00
52 A/F SENSOR 1 HEATER
2.DETECT MALFUNCTIONING PART
Check the following.
 20 A fuse (No. 43)
 Harness for open or short between A/F sensor 1 and fuse
 Loose or poor connection for each connector and harness
>> Repair or replace harness or connectors.
3.CHECK A/F SENSOR 1 HEATER OUTPUT 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. 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 A/F SENSOR 1 HEATER
Refer to EC-182, "
Component Inspection (A/F Sensor 1 Heater)".
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 5.
5.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 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
6.CHECK INTERMITTENT INCIDENT
Perform GI-40, "
Intermittent Incident".
>> INSPECTION END
Component Inspection (A/F Sensor 1 Heater)INFOID:0000000006217777
1.CHECK AIR FUEL RATIO (A/F) SENSOR 1
1. Turn ignition switch OFF.
2. Disconnect air fuel ratio (A/F) sensor 1 harness connector.
3. Check resistance between A/F sensor 1 terminals as per the following.
DTC A/F sensor 1 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0031, P0032 1 F67 2 F11048
Existed
P0051, P0052 2 F68 2 53
Terminal Resistance
2 and 5 2.0 - 3.2 Ω [at 25 °C (77 °F)]
Revision: 2010 May2011 QX56

EC-184
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P0037, P0038, P0057,
P0058 HO2S2 HEATER
P0037, P0038, P0057, P0058 HO2S2 HEATER
DTC LogicINFOID:0000000006217778
DTC DETECTION LOGIC
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.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
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. Start 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 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-184, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217779
1.CHECK HEATED OXYGEN SENSOR 2 (HO2S2) POWER SUPPLY CIRCUIT
1. Disconnect heated oxygen sensor 2 (HO2S2) harness connector.
2. Turn ignition switch ON.
3. Check the voltage between HO2S2 harness connector and ground.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0037 HO2S2 HTR (B1)
[Heated oxygen sensor 2
heater (bank 1) control cir-
cuit low] The current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater
circuit is open or shorted.)
 Heated oxygen sensor 2 heater
P0038 HO2S2 HTR (B1)
[Heated oxygen sensor 2
heater (bank 1) control cir-
cuit high] The current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater
circuit is shorted.)
 Heated oxygen sensor 2 heater
P0057 HO2S2 HTR (B2)
[Heated oxygen sensor 2
heater (bank 2) control cir-
cuit low] The current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater
circuit is open or shorted.)
 Heated oxygen sensor 2 heater
P0058 HO2S2 HTR (B2)
[Heated oxygen sensor 2
heater (bank 2) control cir-
cuit high] The current amperage in the heated oxygen sensor
2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater
circuit is shorted.)
 Heated oxygen sensor 2 heater
Revision: 2010 May2011 QX56

P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-185
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Is the inspection result normal?
YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
 20 A fuse (No. 43)
 Harness for open or short between heated oxygen sensor 2 and fuse
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
3.CHECK HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between HO2S2 harness connector and ECM harness connector.
4. 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 HEATER
Refer to EC-186, "
Component Inspection (HO2 Sensor 2 Heater)".
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 EX-5, "
Removal and Installation".
CAUTION:
 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
6.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
DTC HO2S2
Ground Voltage
Bank Connector Terminal
P0037, P0038 1 F87 2 Ground Battery voltage
P0057, P0058 2 F88 2
DTC HO2S2 ECM
Continuity
Bank Connector Terminal Connector Terminal
P0037, P0038 1 F87 3 F 11147
Existed
P0057, P0058 2 F88 3 52
Revision: 2010 May2011 QX56

EC-186
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P0037, P0038, P0057,
P0058 HO2S2 HEATER
Component Inspection (HO2 Sensor 2 Heater)
INFOID:0000000006217780
1.CHECK HEATED OXYGEN SENSOR 2 HEATER
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 2 (HO2S2) harness connector.
3. Check resistance between HO2S2 terminals as follows.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.REPLACE HEATED OXYGEN SENSOR 2
Replace malfunctioning heated oxygen sensor 2. Refer to EX-5, "
Removal and Installation".
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
Terminal Resistance2 and 3 3.4 - 4.4 Ω [at 25 °C (77 °F)]
1 and 2, 3, 4 ∞ Ω
(Continuity should not exist)
4 and 1, 2, 3
Revision: 2010 May2011 QX56

P006A, P0101 MAF SENSOREC-187
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P006A, P0101 MAF SENSOR
DTC LogicINFOID:0000000006288269
DTC DETECTION LOGIC
NOTE:
If DTC P006A or P0101 is displayed with other DTC,
first perform the trouble diagnosis for other DTC.
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.
If engine will not start or stops soon, wait at leas t 10 seconds with engine stopped (Ignition switch ON) instead
of running engine at idle speed.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
WITH CONSULT-III
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to normal operating temperature.
3. Accelerate the vehicle from 0 km/h (0 MPH) to 88 km/h (55 MPH) under the following conditions:
CAUTION:
Always drive at a safe speed.
NOTE:
 Accelerate with the accelerator pedal kept constant.
 The acceleration at engine speed 2,000 and 3,000 rpm allows easy diagnoses
4. Check 1st trip DTC. WITHOUT CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. With selector lever in D position, accelerate the vehicle from 0 km/h (0 MPH) to 88 km/h (55 MPH) under
the following conditions:
NOTE:
 Accelerate with the accelerator pedal kept constant.
 The acceleration at engine speed 2,000 and 3,000 rpm allows easy diagnoses.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P006A MAP-MAF CORELTION-B1
(Manifold pressure
- mass air
flow correlation) A difference exceeding the specified value develops
between a value transmitted from the manifold absolute
pressure sensor to ECM and an estimated intake pres-
sure of intake manifold calculated by ECM, based on a
mass sir flow sensor signal.  Harness or connectors
(The sensor circuit is open
or shorted.)
 Mass air flow sensor
 Manifold absolute pressure
sensor
 EVAP control system pres-
sure sensor
 Intake air leaks
 Intake air temperature sen- sor
P0101 MAF SEN/CIRCUIT-B1
(Mass air flow sensor circuit
range/performance) A difference exceeding the specified value develops
between a signal transmitted from the mass air flow
sensor to ECM.
Mass air flow sensor
ACCEL SEN 1 1.4 – 2.0 V
Selector lever D position
Revision: 2010 May2011 QX56

EC-188
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P006A, P0101 MAF SENSOR
CAUTION:
Always drive at a safe speed.
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-188, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288270
1.CHECK INTAKE SYSTEM
Check the following for connection.
 Air duct
 Vacuum hoses
 Intake air passage between air duct and intake manifold
Is the inspection result normal?
YES >> GO TO 2.
NO >> Reconnect the parts.
2.CHECK MASS AIR FLOW SENS OR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between mass air flow sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between mass air flow sensor and ECM
 Harness for open or short between mass air flow sensor and IPDM E/R
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
4.CHECK MASS AIR FLOW SENSOR GR OUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between mass air flow sensor harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
Accelerator pedal position sensor 1 Ground Voltage (V)
Connector Terminal
E110 (Whthout ICC) 3 Ground 1.4 – 2.0
E67 (With ICC) 10
Mass air flow sensor Ground Voltage
Connector Terminal
F31 5 Ground Battery volt-
age
Mass air flow sensor ECM Continu-
ity
Connec-
tor Te r m i n a l Connec-
tor Te r m i n a l
F 3 1 4 F 111 2 5 E x i s t e d
Revision: 2010 May2011 QX56

EC-190
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P006A, P0101 MAF SENSOR
Component Inspection (MAF Sensor)
INFOID:0000000006288271
1.CHECK MASS AIR FLOW SENSOR-I
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Start engine and warm it up to normal operating temperature.
4. Connect CONSULT-III and select “DATA MONITOR” mode.
5. Select “MAS A/F SE-B1”, and check the indication.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Reconnect all harness connectors disconnected.
3. Start engine and warm it up to normal operating temperature.
4. Check the voltage between ECM harness connector terminals under the following conditions.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.CHECK FOR THE CAUSE OF UNEVEN AIR FL OW THROUGH MASS AIR FLOW SENSOR
1. Turn ignition switch OFF.
2. Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
- Crushed air ducts
- Malfunctioning seal of air cleaner element
- Uneven dirt of air cleaner element
- Improper specification of intake air system parts
Is the inspection result normal?
YES >> GO TO 4.
NO >> GO TO 3.
3.CHECK MASS AIR FLOW SENSOR-II
WITH CONSULT-III
1. Repair or replace malfunctioning part.
2. Start engine and warm it up to normal operating temperature.
3. Connect CONSULT-III and select “DATA MONITOR” mode.
4. Select “MAS A/F SE-B1””, and check the indication.
Monitor item Condition Indication (V)
MAS A/F SE-B1 Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operating temperature.) 0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
ECM Condition Voltage (V)
Connector +–
Terminal Terminal
F 111 22
(MAF sensor signal) 25Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operat-
ing temperature.)
0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal
operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
Revision: 2010 May2011 QX56

P006A, P0101 MAF SENSOREC-191
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*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
WITHOUT CONSULT-III
1. Repair or replace malfunctioning part.
2. Start engine and warm it up to normal operating temperature.
3. Check the voltage between ECM harness connector terminals under the following conditions.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 4.
4.CHECK MASS AIR FLOW SENSOR-III
WITH CONSULT-III
1. Turn ignition switch OFF.
2. Disconnect mass air flow sensor har ness connector and reconnect it again.
3. Start engine and warm it up to normal operating temperature.
4. Connect CONSULT-III and select “DATA MONITOR” mode.
5. Select “MAS A/F SE-B1” , and check the indication.
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
WITHOUT CONSULT-III
1. Turn ignition switch OFF.
2. Disconnect mass air flow sensor har ness connector and reconnect it again.
3. Start engine and warm it up to normal operating temperature.
4. Check the voltage between ECM harness connector terminals under the following conditions.
Monitor item Condition Indication (V)
MAS A/F SE-B1 Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operating temperature.) 0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
ECM
Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
F 111 22
(MAF sensor signal) 25Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operat-
ing temperature.)
0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal
operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
Monitor item Condition Indication (V)
MAS A/F SE-B1 Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operating temperature.) 0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
Revision: 2010 May2011 QX56

EC-192
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P006A, P0101 MAF SENSOR
*: Check for linear voltage rise in response to engine being increased to about 4,000 rpm.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Clean or replace malfunctioning mass air flow sensor. Refer to
EM-27, "
Removal and Installation".
ECM
Condition Voltage (V)
Connector +–
Te r m i n a l Te r m i n a l
F 111 22
(MAF sensor signal) 25Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal operat-
ing temperature.)
0.9 - 1.1
2,500 rpm (Engine is warmed-up to normal
operating temperature.) 1.4 - 1.9
Idle to about 4,000 rpm 0.9 - 1.1 to Approx. 2.4*
Revision: 2010 May2011 QX56