Page 242 of 720
EC-242
DTC P0125 ECT SENSOR
Revision: 2006 November2007 350Z
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-141, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-225, "
Wiring Diagram" .
>>INSPECTION END
Component InspectionNBS00066
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 InstallationNBS00067
ENGINE COOLANT TEMPERATURE SENSOR
Refer to CO-28, "WATER OUTLET AND WATER PIPING" .
PBIB2005E
Engine coolant
temperature°C (°F)Resistance kΩ
20 (68) 2.37 - 2.63
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
SEF012P
Page 243 of 720

DTC P0127 IAT SENSOR
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DTC P0127 IAT SENSORPFP:22630
Component DescriptionNBS00068
The intake air temperature sensor (1) is built into mass air flow sen-
sor. 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 values and is measured between ECM terminal 67 [Intake
air temperature sensor (bank 1)] 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 LogicNBS00069
DTC Confirmation ProcedureNBS0006A
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-III
1. Wait until engine coolant temperature is less than 90°C (194°F)
a. Turn ignition switch ON.
b. Select “DATA MONITOR” mode with CONSULT-III.
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.
NOTE:
Perform the following steps before engine coolant temperature is above 90°C (194°F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
PBIA9559J
Intake air temperature
°C (°F)Voltage* V Resistance kΩ
25 (77) 3.3 1.800 - 2.200
80 (176) 1.2 0.283 - 0.359
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0127
0127Intake air temperature
too highRationally 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
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DTC P0127 IAT SENSOR
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3. CHECK INTERMITTENT INCIDENT
Refer to EC-141, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
Refer to EC-219, "
Wiring Diagram" .
>>INSPECTION END
Component InspectionNBS0006C
INTAKE AIR TEMPERATURE SENSOR
1. Check resistance between mass air flow sensor (with intake air
temperature sensor) (bank 1) (1) terminals 5 and 6 under the fol-
lowing conditions.
2. If NG, replace mass air flow sensor (with intake air temperature
sensor) (bank 1).
Removal and InstallationNBS0006D
MASS AIR FLOW SENSOR
Refer to EM-15, "AIR CLEANER AND AIR DUCT" .
Intake air temperature °C (°F) Resistance kΩ
25 (77) 1.800 - 2.200
PBIA9559J
SEF012P
Page 248 of 720

EC-248
DTC P0130, P0150 A/F SENSOR 1
Revision: 2006 November2007 350Z
DTC P0130, P0150 A/F SENSOR 1PFP:22693
Component DescriptionNBS006U5
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is composed an elec-
trode layer, 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.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of about 800°C
(1,472°F).
CONSULT-III Reference Value in Data Monitor ModeNBS000ET
Specification data are reference values.
On Board Diagnosis LogicNBS000EU
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal fluctuates according to fuel feedback control.
DTC Confirmation ProcedureNBS006U6
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 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 more than 11V at idle.
PROCEDURE FOR MALFUNCTION A
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Let engine idle for 2 minutes.
PBIB3559E
PBIB3354E
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates around 2.2V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P0130
0130
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit
The A/F signal computed by ECM from the A/
F sensor 1 signal is constantly in the range
other than approx. 2.2V.
Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
Air fuel ratio (A/F) sensor 1 P0150
0150
(Bank 2)The A/F signal computed by ECM from the A/
F sensor 1 signal is constantly approx. 2.2V.
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DTC P0130, P0150 A/F SENSOR 1
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Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-III.
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-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1W/RA/F sensor 1 heater
(bank 1)[Engine is running]
Warm-up condition
Idle speed
(More than 140 seconds after starting
engine)2.9 - 8.8V
57 L A/F sensor 1 (bank 1)[Ignition switch: ON]2.2V
61 R A/F sensor 1 (bank 1)[Ignition switch: ON]
Warm-up condition
Engine speed: 2,000 rpm1.8V
Output voltage varies with air
fuel ratio.
PBIB3538E
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DTC P0130, P0150 A/F SENSOR 1
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Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-III.
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-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
5GY/LA/F sensor 1 heater
(bank 2)[Engine is running]
Warm-up condition
Idle speed
(More than 140 seconds after starting
engine)2.9 - 8.8
65 PU A/F sensor 1 (bank 2)[Ignition switch: ON]2.2V
66 LG A/F sensor 1 (bank 2)[Ignition switch: ON]
Warm-up condition
Engine speed: 2,000 rpm1.8V
Output voltage varies with air
fuel ratio.
PBIB3538E
Page 257 of 720

DTC P0131, P0151 A/F SENSOR 1
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Revision: 2006 November2007 350Z
DTC P0131, P0151 A/F SENSOR 1PFP:22693
Component DescriptionNBS006UB
The air fuel ratio (A/F) sensor 1 is a planar one-cell limit current sen-
sor. The sensor element of the A/F sensor 1 is composed an elec-
trode layer, 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.
The exhaust gas components diffuse through the diffusion layer at
the sensor cell. An electrode layer is applied voltage, and this current
relative oxygen density in lean. Also this current relative hydrocar-
bon density in rich.
Therefore, the A/F sensor 1 is able to indicate air fuel ratio by this
electrode layer of current. In addition, a heater is integrated in the
sensor to ensure the required operating temperature of about 800°C
(1,472°F).
CONSULT-III Reference Value in Data Monitor ModeNBS006UC
Specification data are reference values.
On Board Diagnosis LogicNBS006UD
To judge the malfunction, the diagnosis checks that the A/F signal computed by ECM from the A/F sensor 1
signal fluctuates according to fuel feedback control.
PBIB3559E
PBIB3354E
MONITOR ITEM CONDITION SPECIFICATION
A/F SEN1 (B1)
A/F SEN1 (B2)
Engine: After warming upMaintaining engine speed at
2,000 rpmFluctuates around 2.2V
DTC No. Trouble diagnosis name DTC detecting condition Possible Cause
P0131
0131
(Bank 1)
Air fuel ratio (A/F) sensor 1
circuit low voltage
The A/F signal computed by ECM from the A/
F sensor 1 signal is constantly approx. 0V.
Harness or connectors
(The A/F sensor 1 circuit is open or
shorted.)
Air fuel ratio (A/F) sensor 1 P0151
0151
(Bank 2)
Page 260 of 720
EC-260
DTC P0131, P0151 A/F SENSOR 1
Revision: 2006 November2007 350Z
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-III.
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-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1W/RA/F sensor 1 heater
(bank 1)[Engine is running]
Warm-up condition
Idle speed
(More than 140 seconds after starting
engine)2.9 - 8.8V
57 L A/F sensor 1 (bank 1)[Ignition switch: ON]2.2V
61 R A/F sensor 1 (bank 1)[Ignition switch: ON]
Warm-up condition
Engine speed: 2,000 rpm1.8V
Output voltage varies with air
fuel ratio.
PBIB3538E