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DTC P0112, P0113 IAT SENSOR
EC-221
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2. CHECK INTAKE AIR TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect mass air flow sensor (with intake air temperature sensor) (bank 1) harness connector.
2. Turn ignition switch ON.
3. Check voltage between mass air flow sensor (with intake air
temperature sensor) (bank 1) terminal 5 and ground with CON-
SULT-III or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3. CHECK INTAKE AIR TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between mass air flow sensor (with intake air temperature sensor) (bank 1) ter-
minal 6 and ECM terminal 68.
Refer to Wiring Diagram.
4. Also check harness for short to ground and 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 INTAKE AIR TEMPERATURE SENSOR
Refer to EC-222, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace mass air flow sensor (with intake air temperature sensor) (bank 1).
5. CHECK INTERMITTENT INCIDENT
Refer to EC-141, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
1. Mass air flow sensor (with intake air
temperature sensor) (bank 1)2. Mass air flow sensor (with intake air
temperature sensor) (bank 2)
Voltage: Approximately 5V
PBIB3501E
PBIB1169E
Continuity should exist.
Page 222 of 720
EC-222
DTC P0112, P0113 IAT SENSOR
Revision: 2006 November2007 350Z
Component InspectionNBS0005L
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 InstallationNBS0005M
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 223 of 720

DTC P0117, P0118 ECT SENSOR
EC-223
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DTC P0117, P0118 ECT SENSORPFP:22630
Component DescriptionNBS0005N
The engine coolant temperature (ECT) sensor 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 electrical resistance of
the thermistor decreases as temperature increases.
*: This data is reference values and is measured between ECM terminal 71 (Engine
coolant temperature sensor) 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.
On Board Diagnosis LogicNBS0005O
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.
SEF594K
Engine coolant temperature
°C (°F)Voltage* V Resistance kΩ
−10 (14) 4.4 7.0 - 11.4
20 (68) 3.5 2.37 - 2.63
50 (122) 2.2 0.68 - 1.00
90 (194) 0.9 0.236 - 0.260
SEF012P
DTC No.Trouble Diagnosis
NameDTC Detecting Condition Possible Cause
P0117
0117Engine coolant tem-
perature sensor cir-
cuit low inputAn excessively low voltage from the sensor is
sent to ECM.
Harness or connectors
(The sensor circuit is open or shorted.)
Engine coolant temperature sensor
P0118
0118Engine coolant tem-
perature sensor cir-
cuit high inputAn excessively high voltage from the sensor is
sent to ECM.
Detected items Engine operating condition in fail-safe mode
Engine coolant temper-
ature sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning ignition switch ON
or START.
CONSULT-III displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided
(CONSULT-III display)
Just as ignition switch is turned ON or START 40°C (104°F)
More than approx. 4 minutes after ignition ON or
START80°C (176°F)
Except as shown above40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cooling fan operates
while engine is running.
Page 224 of 720
EC-224
DTC P0117, P0118 ECT SENSOR
Revision: 2006 November2007 350Z
DTC Confirmation ProcedureNBS0005P
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-III
1. Turn ignition switch ON and wait at least 5 seconds.
2. Check DTC.
3. If DTC is detected, go to EC-226, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-III” above.
Page 225 of 720
DTC P0117, P0118 ECT SENSOR
EC-225
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Wiring DiagramNBS0005Q
TBWT1629E
Page 226 of 720
EC-226
DTC P0117, P0118 ECT SENSOR
Revision: 2006 November2007 350Z
Diagnostic ProcedureNBS0005R
1. CHECK GROUND CONNECTIONS
Models with VDC system, navigation system or telephone
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body. Refer to EC-150, "
Ground Inspection" .
Models without VDC system, navigation system and telephone
1. Turn ignition switch OFF.
2. Loosen and retighten ground screws on the body. Refer to EC-150, "
Ground Inspection" .
OK or NG
OK >> GO TO 2.
NG >> Repair or replace ground connections.
1. Body ground E17 2. Body ground E43 3. Body ground B102
:Vehicle front
1. Body ground E17 2. Body ground E43 3. Body ground F152
(Passenger side view with dash side
finisher removed)
:Vehicle front
PBIB3560E
PBIB3561E
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DTC P0117, P0118 ECT SENSOR
EC-227
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2. CHECK ENGINE COOLANT TEMPERATURE SENSOR POWER SUPPLY CIRCUIT
1. Disconnect engine coolant temperature sensor harness connec-
tor (1).
2. Turn ignition switch ON.
3. Check voltage between engine coolant temperature sensor ter-
minal 1 and ground with CONSULT-III or tester.
OK or NG
OK >> GO TO 3.
NG >> Repair open circuit or short to ground or short to power
in harness or connectors.
3. CHECK ENGINE COOLANT TEMPERATURE SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ENGINE COOLANT TEMPERATURE sensor terminal 2 and ECM ter-
minal 84.
Refer to Wiring Diagram.
4. Also check harness for short to ground and 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 ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-228, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace engine coolant temperature sensor.
5. CHECK INTERMITTENT INCIDENT
Refer to EC-141, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
: Vehicle front
PBIB3503E
Voltage: Approximately 5V
PBIB0080E
Continuity should exist.
Page 228 of 720
EC-228
DTC P0117, P0118 ECT SENSOR
Revision: 2006 November2007 350Z
Component InspectionNBS0005S
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 InstallationNBS0005T
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