Volvo v40 18si

Hi Chris.

p0304 = Number 4 Cylinder Misfire Detected

Faulty spark plug 4
Clogged or faulty fuel injector 4
Faulty ignition coil 4
Fuel injector 4 harness is open or shorted
Fuel injector 4 circuit poor electrical connection
Ignition coil 4 harness is open or shorted
Ignition coil 4 circuit poor electrical connection
Insufficient cylinder 4 compression
Incorrect fuel pressure
Intake air leak

The P0304 code means that the cylinder 4 is misfiring or is randomly misfiring. Start by checking for intake leaks an if no leaks are found the next step is to replace the spark plugs on cylinder 4.


p0102 = Mass or Volume Air Flow Circuit Low Input

Faulty mass air flow sensor
Intake air leaks
Dirty mass air flow sensor
Dirty mass air filter
Mass air flow sensor harness is open or shorted
Mass air flow sensor circuit poor electrical connection

Before replacing the mass air flow sensor, try replacing the air filter and cleaning the air flow sensor with low compress air or mass air flow sensor cleaner.
Reset code and drive vehicle.
If the code comes back, it may be necessary to replaced the mass air flow sensor.


p0154 = O2 Sensor Circuit No Activity Detected Sensor 1 Bank 2

Faulty Front Heated Oxygen Sensor Bank 2
Front Heated Oxygen Sensor Bank 2 harness is open or shorted
Front Heated Oxygen Sensor Bank 2 circuit poor electrical connection
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks

Replacing the Front Heated Oxygen Sensor Bank 2 usually takes care of the problem.


p0113 = Intake Air Temperature Sensor Circuit High

Faulty Intake Air Temperature (IAT) sensor
Dirty air filter
Intake Air Temperature (IAT) sensor harness is open or shorted
Intake Air Temperature (IAT) sensor circuit poor electrical connection

The Intake Air Temperature (IAT) sensor is built into mass air flow sensor or in some vehicles mounted to the air filter duct housing. The sensor detects intake air temperature and transmits a signal to the Engine Control Module (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. The Intake Air Temperature signal is used as an input for various systems in the vehicle.



Hope this helps
FYT

http://www.autocodes.com/make/nissan

This is the 2001-2012 Toyota Tacoma wiring diagram, Toyota Tacoma IAT (Intake Air Temperature) Sensor Location and the Toyota Tacoma MAF (Mass Air Flow) Sensor Location, also included is a pinout of the sensor. You are likely installing a performance chip or a cold air intake kit for increased HP (Horsepower). You will want to be sure to disconnect the car battery before adding performance products.




Here is the Toyota Tacoma's Iat sensor diagram:

P0303 Code - Cylinder #3 Misfire
P0110 DTC - IAT Circuit Malfunction
P2195 O2 Sensor Signal Biased/Stuck Lean (Bank 1 Sensor 1) Code
Potential causes of a P2195 code include:
p2195
p219521

• Oxygen (O2) or A/F ratio sensor or sensor heater malfunction
• Open or short in O2 sensor circuit (wiring, harness)
• Fuel pressure or fuel injector problem
• Faulty PCM
• Intake air or engine vacuum leaks
• Faulty fuel injector(s)
• Fuel pressure too high or too low
• PCV system leak/fault
• A/F sensor relay faulty
• MAF sensor malfunction
• ECT sensor malfunction
• Fuel pressure too low
• Fuel leak
• Air suction in air intake system
• A code P0303 may mean that one or more of the following has happened:
  

• Faulty spark plug or wire
• Faulty coil (pack)
• Faulty oxygen sensor(s)
• Faulty fuel injector
• Burned exhaust valve
• Faulty catalytic converter(s)
• Running out of fuel
• Poor compression
• Defective computer
• Potential causes of the P0110 DTC include:
  
• 
  po110
  • IAT sensor shifted out of airflow
  • Bad IAT sensor
  • Shorted to ground or open on signal circuit to IAT
  • Open in ground circuit to IAT
  • Poor connection at IAT (backed out terminals, broken connector locks, etc.)
  • Bad PCM

The Inlet Air Temperature sensor (IAT) located in an air passage in the intake manifold measures the incoming air temperature.
Cold air is denser, contains more oxygen, and therefore requires a richer mixture.

REMOVAL & INSTALLATION

1. Disconnect the negative battery cable.
   
2. Disconnect the wiring to the IAT.
   
3. Remove the sensor from the intake manifold (MFI engines) or air cleaner/tube (SFI engines).

To install:

1. Clean the sensor area. Install the sensor into the intake manifold and tighten to 12-15 ft. lbs. (16-24 Nm) on MFI engines. Fasten the twist-lock part on SFI engines.
   
2. Attach the wiring to the unit.
   
3. Connect the negative battery cable.

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.

Thank you for using FixYa, have a nice day.

The Intake Air Temperature (IAT) sensor is the same as the Manifold Air Temperature (MAT) sensor on earlier models. IAT is located in or near the air intake duct (click image for zoom).



Fig.: On 1996-98 vehicles, the IAT sensor is mounted in the rear air intake duct


Hope this helps (remember to rate this free answer).

Fig. Component Location Chart-2000 MPV

1 PCM 2 Mass air flow (MAF)/intake air temperature (IAT) sensor 3 Throttle position (TP) sensor 4 Fuel tank pressure sensor 5 Engine coolant temperature (ECT) sensor 6 Crankshaft position (CKP) sensor 7 Camshaft position (CMP) sensor 8 Knock sensor 9 Heated oxygen sensor (HO2S) (front, LH) 10 Heated oxygen sensor (HO2S) (front, RH) 11 Heated oxygen sensor (HO2S) (rear, LH) 12 Heated oxygen sensor (HO2S) (rear, RH) 13 EGR boost sensor 14 Power steering pressure (PSP) switch 15 Main relay


Fig. Component Location Chart-2001 MPV

1 PCM 2 Mass air flow (MAF)/Intake air temperature (IAT) sensor 3 Throttle position (TP) sensor 4 Engine coolant temperature (ECT) sensor 5 Crankshaft position (CKP) sensor 6 Camshaft position (CMP) sensor 7 Knock sensor 8 Heated oxygen sensor (HO2S) (front, LH) 9 Heated oxygen sensor (HO2S) (front, RH) 10 Heated oxygen sensor (HO2S) (rear, LH)* 11 Heated oxygen sensor (HO2S) (rear, RH)* 12 EGR boost sensor


Fig. Component Location Chart- 2002-06 MPV

The Intake Air Temperature (IAT) sensor determines the air temperature inside the intake manifold. Resistance changes in response to the ambient air temperature. The sensor has a negative temperature coefficient. As the temperature of the sensor rises the resistance across the sensor decreases. This provides a signal to the PCM indicating the temperature of the incoming air charge. This sensor helps the PCM to determine spark timing and air/fuel ratio. Information from this sensor is added to the pressure sensor information to calculate the air mass being sent to the cylinders. The IAT is a two wire sensor, a 5-volt reference signal is sent to the sensor and the signal return is based upon the change in the measured resistance due to temperature.



Fig. 1: The IAT sensor is located in the air cleaner outlet tube-2.2L engine and 2.4L engine

Hope helped.

I recently took my car in for this problem. The thermostat was replaced a year ago. This time they replaced the thermostat and the IAT (air intake temperature sensor). The thermostat was 20 and the IAT was 50, with labor it all came to $140. Most sites online that I found suggested replacing both the sensor and the thermostat at the same time. When the thermostat goes, it usually takes the sensor with it. So I'd have them replace your sensor too. Good luck.

it is the air Intake Temperature Sensor located at the air cleaner housing.

P0110 - Intake Air Temperature (IAT) Sensor Circuit

P0111 - Intake Air Temperature (IAT) Sensor Performance

P0112 - Intake Air Temperature (IAT) Sensor Circuit Low Voltage

P0113 - Intake Air Temperature (IAT) Sensor Circuit High Voltage

P0114 - Intake Air Temperature Circuit Intermittent ,hope this helps you