Nissan Altima (L32) 2007-2012 Service Manual: P0127 IAT sensor
Description
The intake air temperature sensor is built-into the 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 rise in temperature.
<Reference data>
*: These data are reference values and are measured between ECM terminals 50 (Intake air temperature sensor) and 56 (Sensor ground).
DTC Logic
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
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
1. Wait until engine coolant temperature is less than 90°C (194°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 90°C (194°F), turn ignition switch OFF and cool down engine.
NOTE: Perform the following steps before engine coolant temperature is approximately 90°C (194°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.
Follow the procedure “With CONSULT-III” above.
Is 1st trip DTC detected? YES >> Go to EC-1222, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis Procedure
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E9. Refer to Ground Inspection in GI-45, "Circuit 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-1222, "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 GI-42, "Intermittent Incident".
>> INSPECTION END
Component Inspection
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 sensor terminals as per the following.
Is the inspection result normal? YES >> INSPECTION END
NO >> Replace mass air flow sensor (with intake air temperature sensor).
P0125 ECT sensor
Description 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 ...P0128 Thermostat function
DTC Logic DTC DETECTION LOGIC NOTE: If DTC P0128 is displayed with DTC P0300, P0301, P0302, P0303, P0304, P0305 or P0306, first perform the trouble diagnosis for DTC P0300, P0301, P0302, P0303, ...Other materials:
Symptom diagnosis
SQUEAK AND RATTLE TROUBLE DIAGNOSES
Work Flow
CUSTOMER INTERVIEW
Interview the customer if possible, to determine the conditions that exist
when the noise occurs. Use the Diagnostic
Worksheet during the interview to document the facts and conditions when the
noise occurs and any
customer ...
Air mix door motor
Description
SYSTEM DESCRIPTION
Component Parts
Air mix door control system components are:
• Front air control
• Air mix door motors (LCU)
• In-vehicle sensor
• Ambient sensor
• Sunload sensor
• Intake sensor
System Operation
The front air control receives data from each of t ...
Driving on snow or ice
WARNING
● Wet ice (32°F, 0°C and freezing rain),
very cold snow or ice can be slick and
very hard to drive on. The vehicle will
have much less traction or “grip” under
these conditions. Try to avoid driving on
wet ice until the road is salted or
sanded.
● Whatever the condi ...