heater INFINITI QX56 2007 Factory Workshop Manual

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-163
< SERVICE INFORMATION >
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DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
DescriptionINFOID:0000000003531656
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F sensor 1 element at the specified range.
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531657
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531658
DTC Confirmation ProcedureINFOID:0000000003531659
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 between 10.5V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with
CONSULT-II.
2. Start engine and let it idle for at least 10 seconds.
3. If 1st trip DTC is detected, go to EC-167, "
Diagnosis Procedure".
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Air fuel ratio (A/F) sensor 1
heater controlAir fuel ratio (A/F) sensor 1
heater
Mass air flow sensor Amount of intake air
MONITOR ITEM CONDITION SPECIFICATION
A/F S1 HTR (B1)
A/F S1 HTR (B2)• Engine: After warming up, idle the engine 4 - 100%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0031
0031
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater control circuit lowThe current amperage in the air fuel ratio (A/F) sen-
sor 1 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)• Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
• A/F sensor 1 heater P0051
0051
(Bank 2)
P0032
0032
(Bank 1)Air fuel ratio (A/F) sensor
1 heater control circuit
highThe current amperage in the air fuel ratio (A/F) sen-
sor 1 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)• Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
• A/F sensor 1 heater P0052
0052
(Bank 2)
SEF058Y

EC-164
< SERVICE INFORMATION >
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Wiring DiagramINFOID:0000000003531660
BANK 1
Specification data are reference values and are measured between each terminal and ground.
BBWA2788E

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-165
< SERVICE INFORMATION >
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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-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
2 LG/B A/F sensor 1 heater (bank 1)[Engine is running]
•Warm-up condition
• Idle speed
(More than 140 seconds after starting en-
gine)Approximately 2.9 - 8.8V
35 BR/R A/F sensor 1 (bank 1)[Engine is running]
•Warm-up condition
• Engine speed: 2,000 rpmApproximately 1.8V
Output voltage varies with air fuel
ratio.
56 BR/G A/F sensor 1 (bank 1)[Ignition switch: ON]Approximately 2.2V
PBIA8148J

EC-166
< SERVICE INFORMATION >
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
BANK 2
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.
BBWA2789E

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-167
< SERVICE INFORMATION >
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: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000003531661
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Refer to EC-143, "
Ground Inspection".
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2.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.
TER-
MI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
16 G/L A/F sensor 1 (bank 2)[Engine is running]
•Warm-up condition
• Engine speed: 2,000 rpmApproximately 1.8V
Output voltage varies with air fuel
ratio.
24
43GR/G
GR/GA/F sensor 1 heater (bank 2)[Engine is running]
•Warm-up condition
• Idle speed
(More than 140 seconds after starting en-
gine)Approximately 2.9 - 8.8V
75 L/P A/F sensor 1 (bank 2)[Ignition switch: ON]Approximately 2.2V
PBIA8148J
BBIA0354E
BBIA0376E

EC-168
< SERVICE INFORMATION >
DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
3. Check voltage between A/F sensor 1 terminal 4 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors E5, F14
• IPDM E/R harness connector E119
• 15A fuse
• Harness for open or short between A/F sensor 1 and fuse
>> Repair or replace harness or connectors.
4.CHECK A/F SENSOR 1 HEATER OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal 2 (bank 1) or 24, 43 (bank 2) and A/F sensor 1 terminal
3.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK A/F SENSOR 1 HEATER
Refer to EC-168, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning air fuel ratio (A/F) sensor 1.
6.CHECK INTERMITTENT INCIDENT
Perform EC-138
.
>>INSPECTION END
Component InspectionINFOID:0000000003531662
AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Voltage: Battery voltage
PBIB3308E
Continuity should exist.

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-169
< SERVICE INFORMATION >
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1. Check resistance between A/F sensor 1 terminals as follows.
2. If NG, replace air fuel ratio (A/F) sensor 1.
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 sensor, clean exhaust system
threads using Heated Oxygen Sensor Thread Cleaner tool J-
43897-18 or J-43897-12 and approved anti-seize lubricant.
Removal and InstallationINFOID:0000000003531663
AIR FUEL RATIO SENSOR HEATER
Refer to EM-21.
Terminal No. Resistance
3 and 4 1.8 - 2.44 Ω [at 25°C (77°F)]
3 and 1, 2
∞ Ω
(Continuity should not exist)
4 and 1, 2
PBIB3309E

EC-170
< SERVICE INFORMATION >
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
DescriptionINFOID:0000000003531664
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeINFOID:0000000003531665
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000003531666
DTC Confirmation ProcedureINFOID:0000000003531667
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:
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,600OFF
Below 3,600 rpm after the following conditions are met.
• Engine: After warming up
• Keeping the engine speed between 3,500 and 4,000 rpm for 1
minute and at idle for 1 minute under no loadON
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
HO2S2 HTR (B2)• Engine speed: Below 3,600 rpm after the following conditions are met.
- Engine: After warming up
- Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and
at idle for 1 minute under no loadON
• Engine speed: Above 3,600 rpm OFF
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0037
0037
(Bank 1)
Heated oxygen sensor 2
heater control circuit lowThe current amperage in the heated oxygen sen-
sor 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 P0057
0057
(Bank 2)
P0038
0038
(Bank 1)
Heated oxygen sensor 2
heater control circuit highThe current amperage in the heated oxygen sen-
sor 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 P0058
0058
(Bank 2)

DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-171
< SERVICE INFORMATION >
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H
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EC
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P O
Before performing the following procedure, confirm that battery voltage is between 10.5V and 16V at
idle.
WITH CONSULT-II
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-II.
2. Start engine and warm it up to the normal operating tempera-
ture.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start the engine and keep the engine speed between 3,500 rpm
and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
6. If 1st trip DTC is detected, go to EC-175, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-II” above.
SEF174Y

EC-172
< SERVICE INFORMATION >
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
Wiring Diagram
INFOID:0000000003531668
BANK 1
Specification data are reference values and are measured between each terminal and ground.
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.
BBWA2798E