2008 INFINITI FX35 fuel

DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-739
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DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
DescriptionINFOID:0000000001326562
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-III Reference Value in Data Monitor ModeINFOID:0000000001326563
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001326564
DTC Confirmation ProcedureINFOID:0000000001326565
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is between 10.5V and 16V at
idle.
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-743, "
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 0 - 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 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
P0051
0051
(Bank 2)
P0032
0032
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater 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
P0052
0052
(Bank 2)
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DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-743
< SERVICE INFORMATION > [VK45DE]
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: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnosis ProcedureINFOID:0000000001326567
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-723, "
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
COLOR ITEM CONDITION DATA (DC Voltage)
24 P A/F sensor 1 heater
(Bank 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 5V
57 G A/F sensor 1 (Bank 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 2.6V
58 L Approximately 2.3V
76 R Approximately 3.1V
77 OR Approximately 2.3V
PBIB1584E
PBIB2195E
: Vehicle front 1. A/F sensor 1 (Bank 2)
harness connector2. A/F sensor 1 (Bank 1)
harness connector
PBIB3246E
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EC-744
< SERVICE INFORMATION >[VK45DE]
DTC P0031, P0032,
P0051, P0052 A/F SENSOR 1 HEATER
3. Check voltage between A/F sensor 1 terminal 3 and ground with
CONSULT-III or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
 Harness connectors E19, F49
 IPDM E/R connector E7
 10A 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 the following; ECM terminal 2 and A/F sensor 1 (Bank 1) terminal 4 or
ECM terminal 24 and A/F sensor 1 (Bank 2) terminal 4.
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-744, "
Component Inspection".
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning air fuel ratio sensor 1.
6.CHECK INTERMITTENT INCIDENT
Refer to EC-717
.
>> INSPECTION END
Component InspectionINFOID:0000000001326568
AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Voltage: Battery voltage
PBIB1683E
Continuity should exist.
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DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-745
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Check resistance between terminals 3 and 4.
Check continuity between terminals
3 and 1, 2, 5, 6, terminals 4 and
1, 2, 5, 6.
If NG, replace the 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:0000000001326569
AIR FUEL RATIO (A/F) SENSOR 1
Refer to EM-179.
Resistance: 2.3 - 4.3
Ω [at 25 °C (77 °F)]
Continuity should not exist.
PBIB1684E
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EC-768
< SERVICE INFORMATION >[VK45DE]
DTC P0102, P0103 MAF SENSOR
DTC P0102, P0103 MAF SENSOR
Component DescriptionINFOID:0000000001326595
The mass air flow sensor is placed in the stream of intake air. It mea-
sures the intake flow rate by measuring a part of the entire intake
flow. The mass air flow sensor controls the temperature of the hot
wire to a certain amount. The heat generated by the hot wire is
reduced as the intake air flows around it. The more air, the greater
the heat loss.
Therefore, the electric current
supplied to hot wire is changed to
maintain the temperature of the hot wire as air flow increases. The
ECM detects the air flow by means of this current change.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000001326596
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000001326597
These self-diagnoses have the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, the ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000001326598
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
PROCEDURE FOR DTC P0102
1. Start engine and wait at least 5 seconds.
2. Check DTC.
PBIB1604E
MONITOR ITEM CONDITION SPECIFICATION
MAS A/F SE-B1 See EC-709
.
CAL/LD VALUE  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 2.0 - 6.0 g·m/s
2,500 rpm 7.0 - 20.0 g·m/s
DTC No.
Trouble diagnosis
name DTC detecting condition Possible cause
P0102
0102 Mass air flow sensor
circuit low input An excessively low voltage from the sensor is sent
to ECM.  Harness or connectors
(The sensor circuit is open or shorted.)
 Intake air leaks
 Mass air flow sensor
P0103
0103 Mass air flow sensor
circuit high input An excessively high voltage from the sensor is
sent to ECM.  Harness or connectors
(The sensor circuit is open or shorted.)
 Mass air flow sensor
Detected items Engine operating condition in fail-safe mode
Mass air flow sensor circuit Engine speed will no t rise more than 2,400 rpm due to the fuel cut.
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EC-790
< SERVICE INFORMATION >[VK45DE]
DTC P0125 ECT SENSOR
DTC P0125 ECT SENSOR
Component DescriptionINFOID:0000000001326625
NOTE:
If DTC P0125 is displayed with P0117 or P0118, fi
rst perform the trouble diagnosis for DTC P0117 or
P0118. Refer to EC-779
.
The engine coolant temperature sens or is used to detect the engine
coolant temperature. The sensor modifies a voltage signal from the
ECM. The modified signal returns to the ECM as the engine coolant
temperature input. The sensor uses a thermistor which is sensitive to
the change in temperature. The elec trical resistance of the ther-
mistor decreases as temperature increases.

*: These data are reference values and are measured between ECM terminal 73
(Engine coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring in put/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground ot her than ECM terminals, such as the ground.
On Board Diagnosis LogicINFOID:0000000001326626
DTC Confirmation ProcedureINFOID:0000000001326627
CAUTION:
Be careful not to overheat engine.
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check that “COOLAN TEMP/S” is above 10 °C (50 °F).
If it is above 10 °C (50 °F), the test result will be OK.
If it is below 10 °C (50 °F), go to following step.
SEF594K
Engine coolant
temperature °C ( °F) Voltage* V Resistance k
Ω
–10 (14) 4.4 7.0 - 11.4 20 (68) 3.5 2.1 - 2.9
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0125
0125 Insufficient engine cool-
ant temperature for
closed loop fuel control  Voltage sent to ECM from the sensor is not
practical, even when some time has passed
after starting the engine.
 Engine coolant temperature is insufficient for closed loop fuel control.  Harness or connectors
(High resistance in the circuit)
 Engine coolant temperature sensor
Thermostat
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EC-796
< SERVICE INFORMATION >[VK45DE]
DTC P0128 THERMOSTAT FUNCTION
DTC P0128 THERMOSTAT FUNCTION
On Board Diagn
osis LogicINFOID:0000000001326637
Engine coolant temperature has not risen enough to open the thermostat even though the engine has run long
enough.
This is due to a leak in the seal or the thermostat stuck open.
DTC Confirmation ProcedureINFOID:0000000001326638
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
 For best results, perform at ambient temperature of –10 °C (14 °F) or higher.
 For best results, perform at en gine coolant temperature of –10 °C (14 °F) to 71 °C (160 °F).
 Before performing the following procedure, do not fill with the fuel.
WITH CONSULT-III
1. Turn A/C switch OFF.
2. Turn blower fan switch OFF.
3. Turn ignition switch ON.
4. Select “COOLAN TEMP/S” in “DATA MONITOR” mode with CONSULT-III.
5. Check the indication of “COOLAN TEMP/S”.
If it is below 71 °C (160 °F), go to following step.
If it is above 71 °C (160 °F), cool down the engine to less than 71 °C (160 °F), then go to next step.
6. Start engine.
7. Wait at idle for a least 30 minutes. If “COOLAN TEMP/S” increases to more than 71 °C (160 °F) within 30 minutes, turn ignition switch
OFF because the test result will be OK.
8. Check 1st trip DTC.
9. If 1st trip DTC is detected, go to EC-796, "
Diagnosis Procedure".
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Diagnosis ProcedureINFOID:0000000001326639
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-797, "
Component Inspection".
OK or NG
OK >> GO TO 2.
NG >> Replace engine coolant temperature sensor.
2.CHECK THERMOSTST
Refer to CO-53, "
Removal and Installation".
OK or NG
OK >> INSPECTION END
NG >> Replace thermostat.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128
0128 Thermostat function The engine coolant temperature does not reach
to specified temperature even though the en-
gine has run long enough. Thermostat
 Leakage from sealing portion of thermo-
stat
 Engine coolant temperature sensor
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EC-798
< SERVICE INFORMATION >[VK45DE]
DTC P0130, P0150
A/F SENSOR 1
DTC P0130, P0150 A/F SENSOR 1
Component DescriptionINFOID:0000000001326642
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. Ther efore, 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-III Reference Value in Data Monitor ModeINFOID:0000000001326643
Specification data are reference values.
On Board Diagn osis LogicINFOID:0000000001326644
To judge the malfunction, the diagnosis checks that t he A/F signal computed by ECM from the A/F sensor 1
signal fluctuates according to fuel feedback control.
DTC Confirmation ProcedureINFOID:0000000001326645
Perform PROCEDURE FOR MALFUNCTION A first.
If the DTC cannot be confirmed, perform PROCEDURE FOR MALFUNCTION B.
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, 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.
PROCEDURE FOR MALFUNCTION A
SEF579Z
SEF580Z
MONITOR ITEM CONDITION SPECIFICATION
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 condition Possible Cause
P0130
0130
(Bank 1) Air fuel ratio (A/F) sensor
1 circuit A)
The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly in the range other
than approx. 1.5V.
 Harness or connectors
[Air fuel ratio (A/F) sensor 1 circuit
is open or shorted.]
 Air fuel ratio (A/F) sensor 1
P0150
0150
(Bank 2) B)
The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 1.5V.
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