P0125 ECT SENSOREC-169
< COMPONENT DIAGNOSIS > [HR16DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0125 ECT SENSOR
DescriptionINFOID:0000000005398349
The engine coolant temperature 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 ther-
mistor decreases as temperature increases.
*: These data are reference values and are measured between ECM terminal 38
(Engine coolant temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output vo ltage. Doing so may result in damage to the ECM's transis-
tor. Use a ground other than ECM terminals, such as the ground.
DTC LogicINFOID:0000000005398350
DTC DETECTION LOGIC
NOTE:
• If DTC P0125 is displayed with P0 116, first perform the trouble diagnosis for DTC P0116. Refer to EC-
159, "DTC Logic".
• If DTC P0125 is displayed with P0117 or P0118, first perform the trouble di agnosis for DTC P0117 or
P0118. Refer to EC-161, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
>> GO TO 2.
2.CHECK ENGINE COOLANT TEMPERATURE SENSOR FUNCTION
With CONSULT-III
1. Turn ignition switch ON.
SEF594K
Engine coolant temperature
[° C ( °F)] Voltage* (V)
Resistance (kΩ)
–10 (14) 4.47.0 - 11.4
20 (68) 3.52.37 - 2.63
50 (122) 2.20.68 - 1.00
90 (194) 0.90.236 - 0.260
SEF012P
DTC No. Trouble diagnosis name DTC detecting conditionPossible cause
P0125 Insufficient engine coolant
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
Revision: January 20102010 Versa
EC-170
< COMPONENT DIAGNOSIS >[HR16DE]
P0125 ECT SENSOR
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Check that “COOLAN TEMP/S” is above 10
°C (50° F).
With GST
Follow the procedure “With CONSULT-III” above.
Is it above 10
°C (50°F)?
YES >> INSPECTION END
NO >> GO TO 3.
3.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Start engine and run it for 65 minutes at idle speed.
2. Check 1st tip DTC.
If “COOLAN TEMP/S” indication increases to more than 10 °C (50° F) within 65 minutes, stop engine
because the test result will be OK.
CAUTION:
Be careful not to overheat engine.
With GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> EC-170, "Diagnosis Procedure"
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000005398351
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connections E15, E24. Refer to EC-119, "
Ground Inspection".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace ground connection.
2.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-170, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Replace engine coolant temperature sensor.
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.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair or replace thermostat. Refer to CO-23, "
Removal and Installation".
4.CHECK INTERMITTENT INCIDENT
Refer to EC-114, "
Diagnosis Procedure".
>> INSPECTION END
Component InspectionINFOID:0000000005398352
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect engine coolant temperature sensor harness connector.
3. Remove engine coolant temperature sensor.
Revision: January 20102010 Versa
P0125 ECT SENSOREC-171
< COMPONENT DIAGNOSIS > [HR16DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
4. Check resistance between engine coolant temperature sensor
terminals by heating with hot water as shown in the figure.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace engine coolant temperature sensor.
Terminals ConditionResistance
1 and 2 Temperature [ °C ( °F)] 20 (68) 2.37 - 2.63 kΩ
50 (122) 0.68 - 1.00 k Ω
90 (194) 0.236 - 0.260 k Ω
PBIB2005E
Revision: January 20102010 Versa
EC-172
< COMPONENT DIAGNOSIS >[HR16DE]
P0127 IAT SENSOR
P0127 IAT SENSOR
DescriptionINFOID:0000000005398353
The intake air temperature sensor
is built-into mass air flow sensor
(1). 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.
*: These data are reference values and are measured between ECM terminal 46
(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.
DTC LogicINFOID:0000000005398354
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
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:
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.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
With CONSULT-III
1. Wait until engine coolant temperature is less than 96 °C (205 °F)
- Turn ignition switch ON.
- Select “DATA MONITOR” mode with CONSULT-III.
- Check the engine coolant temperature.
- If the engine coolant temperature is not less than 96° C (205°F), turn ignition switch OFF and cool down
engine.
PBIA9559J
Intake air temperature
[° C ( °F)] Voltage* (V)
Resistance (kΩ)
25 (77) 3.31.800 - 2.200
80 (176) 1.20.283 - 0.359
SEF012P
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0127 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
Revision: January 20102010 Versa
P0127 IAT SENSOREC-173
< COMPONENT DIAGNOSIS > [HR16DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
NOTE:
Perform the following steps before engine coolant temperature is above 96
°C (205° F).
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Start engine.
5. Hold vehicle speed at more than 70 km/h (43 MPH) for 100 consecutive seconds.
CAUTION:
Always drive vehicle at a safe speed.
6. Check 1st trip DTC.
With GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Go to EC-173, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000005398355
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connections E15, E24. Refer to EC-119, "
Ground Inspection".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace ground connection.
2.CHECK INTAKE AIR TEMPERATURE SENSOR
Refer to EC-173, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Replace mass air flow sensor ( with intake air temperature sensor).
3.CHECK INTERMITTENT INCIDENT
Refer to EC-114, "
Diagnosis Procedure".
>> INSPECTION END
Component InspectionINFOID:0000000005398356
1.CHECK INTAKE AIR TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect mass air flow sensor harness connector.
3. Check resistance between mass air flow s ensor terminals as per the following.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace mass air flow sensor ( with intake air temperature sensor).
TerminalsCondition Resistance (kΩ)
1 and 2 Intake air temperature [ °C ( °F)] 25 (77) 1.800 - 2.200
Revision: January 20102010 Versa
EC-174
< COMPONENT DIAGNOSIS >[HR16DE]
P0128 THERMOSTAT FUNCTION
P0128 THERMOSTAT FUNCTION
DTC LogicINFOID:0000000005398357
DTC DETECTION LOGIC
NOTE:
If DTC P0128 is displayed with
DTC P0300, P0301, P0302, P0303 or P 0304, first perform the trouble
diagnosis for DTC P0300, P0301, P0302, P0303, P0304. Refer to EC-247, "
DTC Logic".
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 PROCEDURE
1.PRECONDITIONING
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:
• 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 56 °C (133 °F).
• Before performing the following procedure, do not fill with the fuel.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
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 56 °C (133° F), go to following step.
If it is above 56 °C (133° F), cool down the engine to less than 56 °C (133° F). Then go to next steps.
6. Start engine.
7. Drive vehicle for 10 consecutive minutes under the following conditions.
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “COOLAN TEMP/S” indication increases to more than 75 °C (167° F) within 10 minutes, turn igni-
tion switch OFF because the t est result will be OK.
8. Check 1st trip DTC.
With GST
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected?
YES >> Go to EC-174, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000005398358
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to EC-175, "
Component Inspection".
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0128 Thermostat function The engine coolant temperature does not
reach to specified temperature even though
the engine has run long enough. •Thermostat
• Leakage from sealing portion of thermostat
• Engine coolant temperature sensor
VHCL SPEED SE
More than 56km/h (35MPH)
Revision: January 20102010 Versa
P0128 THERMOSTAT FUNCTIONEC-175
< COMPONENT DIAGNOSIS > [HR16DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Is the inspection result normal?
YES >> GO TO 2.
NO >> Replace engine coolant temperature sensor.
2.CHECK THERMOSTAT
Refer to CO-24, "
Inspection".
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace thermostat.
Component InspectionINFOID:0000000005398359
1.CHECK ENGINE COOLANT TEMPERATURE SENSOR
1. Turn ignition switch OFF.
2. Disconnect engine coolant temperature sensor harness connector.
3. Remove engine coolant temperature sensor.
4. Check resistance between engine coolant temperature sensor terminals by heating with hot water as shown in the figure.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace engine coolant temperature sensor.
Terminals ConditionResistance
1 and 2 Temperature [ °C ( °F)] 20 (68) 2.37 - 2.63 kΩ
50 (122) 0.68 - 1.00 k Ω
90 (194) 0.236 - 0.260 k Ω
PBIB2005E
Revision: January 20102010 Versa
EC-176
< COMPONENT DIAGNOSIS >[HR16DE]
P0130 A/F SENSOR 1
P0130 A/F SENSOR 1
DescriptionINFOID:0000000005398360
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 additi on, a heater is integrated in the
sensor to ensure the required operating temperature of about 800° C
(1,472° F).
DTC LogicINFOID:0000000005398361
DTC DETECTION LOGIC
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 PROCEDURE
1.PRECONDITIONING
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 11 V at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE FOR MALFUNCTION A
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Let it idle for 2 minutes.
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-179, "Diagnosis Procedure".
JMBIA0112GB
PBIB3354E
DTC No. Trouble diagnosis name DTC detecting conditionPossible Cause
P0130 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. 2.2 V. • Harness or connectors
(The A/F sensor 1 circuit is open
or shorted.)
• A/F sensor 1
B) The A/F signal computed by ECM from the A/F
sensor 1 signal is constantly approx. 2.2 V.
Revision: January 20102010 Versa