air INFINITI FX35 2005 Service Manual

DTC P0122, P0123 TP SENSOR EC-219
[VQ35DE]
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Revision: 2005 July 2005 FX
Component InspectionABS006N8
THROTTLE POSITION SENSOR
1. Reconnect all harness connectors disconnected.
2. Perform EC-96, "
Throttle Valve Closed Position Learning" .
3. Turn ignition switch ON.
4. Set selector lever to D position.
5. Check voltage between ECM terminals 50 (TP sensor 1signal), 69 (TP sensor 2signal) and body ground under the following
conditions.
6. If NG, replace electric throttle control actuator and go to the next step.
7. Perform EC-96, "
Throttle Valve Closed Position Learning" .
8. Perform EC-97, "
Idle Air Volume Learning" .
Removal and InstallationABS006N9
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EM-19, "INTAKE MANIFOLD COLLECTOR" .
Terminal Accelerator pedal Voltage
50
(Throttle position sensor 1) Fully released More than 0.36V
Fully depressed Less than 4.75V
69
(Throttle position sensor 2) Fully released Less than 4.75V
Fully depressed More than 0.36V
PBIB1608E

DTC P0125 ECT SENSOR EC-221
[VQ35DE]
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Revision: 2005 July 2005 FX
DTC Confirmation ProcedureABS006NC
CAUTION:
Be careful not to overheat engine.
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.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
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.
4. Start engine and run it for 65 minutes at idle speed. If “COOLAN TEMP/S” increases to more than 10 °C (50 °F)
within 65 minutes, stop engine because the test result will
be OK.
5. If DTC is detected, go to EC-221, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureABS006ND
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-170, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-222, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace engine coolant temperature sensor.
SEF174Y
PBIB2625E

EC-222
[VQ35DE]
DTC P0125 ECT SENSOR
Revision: 2005 July 2005 FX
3. CHECK THERMOSTAT OPERATION
When the engine is cold [lower than 70 °C (158 °F)] condition, grasp lower radiator hose and confirm the engine
coolant does not flow.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace thermostat. Refer to CO-26, "
WATER INLET AND THERMOSTAT ASSEMBLY"
.
4. CHECK INTERMITTENT INCIDENT
Refer to EC-163, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-210, "
Wiring Diagram" .
>> INSPECTION END
Component InspectionABS006NE
ENGINE COOLANT TEMPERATURE SENSOR
1. Check resistance between engine coolant temperature sensor
terminals 1 and 2 as shown in the figure.

2. If NG, replace engine coolant temperature sensor.
Removal and InstallationABS006NF
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-26, "WATER INLET AND THERMOSTAT ASSEMBLY" .
PBIB2005E
Engine coolant temperature °C ( °F) Resistance k Ω
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P

DTC P0127 IAT SENSOR EC-223
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Revision: 2005 July 2005 FX
DTC P0127 IAT SENSORPFP:22630
Component DescriptionABS006NG
The intake air temperature sensor is built into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.

*: This data is reference value and is measured between ECM terminal 34 (Intake air
temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.
On Board Diagnosis LogicABS006NH
DTC Confirmation ProcedureABS006NI
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.
CAUTION:
Always drive vehicle at a safe speed.
TESTING CONDITION:
This test may be conducted with the drive wheels lifted in the shop or by driving the vehicle. If a road
test is expected to be easier, it is unnecessary to lift the vehicle.
WITH CONSULT-II
1. Wait until engine coolant temperature is less than 90 °C (194 °F)
a. Turn ignition switch ON.
PBIB1604E
Intake air temperature ° C ( °F) Voltage* V Resistance k
Ω
25 (77) 3.32 1.94 - 2.06
80 (176) 1.23 0.295 - 0.349
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0127
0127 Intake air temperature
too high Rationally incorrect voltage from the sensor is
sent to ECM, compared with the voltage signal
from engine coolant temperature sensor.

Harness or connectors
(The sensor circuit is open or shorted)

Intake air temperature sensor

EC-224
[VQ35DE]
DTC P0127 IAT SENSOR
Revision: 2005 July 2005 FX
b. Select “DATA MONITOR” mode with CONSULT-II.
c. Check the engine coolant temperature.
d. If the engine coolant temperature is not less than 90 °C (194 °F),
turn ignition switch OFF and cool down engine.

Perform the following steps before engine coolant tempera-
ture is above 90 °C (194 °F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-II.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 con- secutive seconds.
6. If 1st trip DTC is detected, go to EC-224, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
Diagnostic ProcedureABS006NJ
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-170, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-225, "
Component Inspection" .
OK or NG
OK >> GO TO 3.
NG >> Replace mass air flow sensor (with intake air temperature sensor).
3. CHECK INTERMITTENT INCIDENT
Refer to EC-163, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-205, "
Wiring Diagram" .
>> INSPECTION END
SEF189Y
PBIB2625E

DTC P0127 IAT SENSOR EC-225
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Revision: 2005 July 2005 FX
Component InspectionABS006NK
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between intake air temperature sensor termi-
nals 5 and 6 under the following conditions.
2. If NG, replace mass air flow sensor (with intake air temperature sensor).
Removal and InstallationABS006NL
MASS AIR FLOW SENSOR
Refer to EM-17, "AIR CLEANER AND AIR DUCT" .
Intake air temperature °C ( °F) Resistance k Ω
25 (77) 1.94 - 2.06
PBIB1604E
SEF012P

EC-228
[VQ35DE]
DTC P0138, P0158 HO2S2
Revision: 2005 July 2005 FX
DTC P0138, P0158 HO2S2PFP:226A0
Component DescriptionABS006OH
The heated oxygen sensor 2, after three way catalyst 1, monitors the
oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor ModeABS006OI
Specification data are reference values.
On Board Diagnosis LogicABS006OJ
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 1 causes the longer
switching time. To judge the malfunctions of heated oxygen sensor
2, ECM monitors whether the voltage is unusually high during the
various driving condition such as fuel-cut.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)

Warm-up condition

After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load. Revving engine from idle to 3,000 rpm
quickly. 0 - 0.3V
←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2) LEAN
←→ RICH
PBIB1848E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0138
0138
(Bank 1) Heated oxygen sensor
2 circuit high voltage An excessively high voltage from the sensor is
sent to ECM.

Harness or connectors
(The sensor circuit is open or shorted)

Heated oxygen sensor 2
P0158
0158
(Bank 2)

DTC P0138, P0158 HO2S2 EC-233
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Revision: 2005 July 2005 FX
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.
Diagnostic ProcedureABS006OM
1. CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten ground three screws on the body. Refer to EC-170, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
2. CHECK HO2S2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Disconnect heated oxygen sensor 2 harness connector.
2. Disconnect ECM harness connector.
3. Check harness continuity between HO2S2 terminal 4 and ECM terminal 78.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to ground or short to power in harness or connectors.
TER-
MINAL NO. WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
55 W/R Heated oxygen sensor 2
(bank 2) [Engine is running]

Warm-up condition

Revving engine from idle to 3,000 rpm
quickly after the following conditions are met
–After keeping the engine speed between
3,500 and 4,000 rpm for 1 minute and at idle
for 1 minute under no load 0 - Approximately 1.0V
78 B/R Sensor ground
(Heated oxygen sensor) [Engine is running]

Warm-up condition

Idle speed
Approximately 0V
PBIB2625E
Continuity should exist.
PBIB1576E

EC-234
[VQ35DE]
DTC P0138, P0158 HO2S2
Revision: 2005 July 2005 FX
3. CHECK HO2S2 INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal and HO2S2 terminal as follows. Refer to Wiring Diagram.
2. Check harness continuity between the following terminals and ground. Refer to Wiring Diagram.
3. Also check harness for short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK HO2S2 CONNECTOR FOR WATER
Check connectors for water.
OK or NG
OK >> GO TO 5.
NG >> Repair or replace harness or connectors.
5. CHECK HEATED OXYGEN SENSOR 2
Refer to EC-235, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace malfunctioning heated oxygen sensor 2.
6. CHECK INTERMITTENT INCIDENT
Refer to EC-163, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>> INSPECTION END
DTC Terminals
Bank
ECM Sensor
P0138 74 1 1
P0158 55 1 2
Continuity should exist.
DTC Terminals
Bank
ECM Sensor
P0138 74 1 1
P0158 55 1 2
Continuity should not exist.
Water should not exist.

DTC P0139, P0159 HO2S2 EC-237
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Revision: 2005 July 2005 FX
DTC P0139, P0159 HO2S2PFP:226A0
Component DescriptionABS006OP
The heated oxygen sensor 2, after three way catalyst 1, monitors the
oxygen level in the exhaust gas on each bank.
Even if switching characteristics of the air fuel ratio (A/F) sensor 1
are shifted, the air-fuel ratio is controlled to stoichiometric, by the sig-
nal from the heated oxygen sensor 2.
This sensor is made of ceramic zirconia. The zirconia generates volt-
age from approximately 1V in richer conditions to 0V in leaner condi-
tions.
Under normal conditions the heated oxygen sensor 2 is not used for
engine control operation.
CONSULT-II Reference Value in Data Monitor ModeABS006OQ
Specification data are reference values.
On Board Diagnosis LogicABS006OR
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 before the three way catalyst 1 causes the
longer switching time. To judge the malfunctions of heated oxygen
sensor 2, ECM monitors whether the switching response of the sen-
sor's voltage is faster than specified during the various driving condi-
tion such as fuel-cut.
SEF327R
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 (B1)
HO2S2 (B2)

Warm-up condition

After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load. Revving engine from idle to 3,000 rpm
quickly. 0 - 0.3V
←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2) LEAN
←→ RICH
SEF302U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0139
0139
(Bank 1) Heated oxygen sensor
2 circuit slow response It takes more time for the sensor to respond
between rich and lean than the specified time.

Harness or connectors
(The sensor circuit is open or shorted)

Heated oxygen sensor 2

Fuel pressure

Fuel injector

Intake air leaks
P0159
0159
(Bank 2)