this is what the 0401 code says:
Diagnostic Trouble Code 0401 points to a problem with the Intake Air Temperature Sensor. The IATS is mounted in the engine air intake duct, downstream of the air cleaner filter. It detects intake air temperature and transmits a signal to the Engine Control Module. The sensor uses a thermistor, a resistor with a value which is inversely proportional to temperature. The IATS is not directly used to control the engine. It is used only for diagnostic purposes. Therefore the engine should start and run normally, even with the Malfunction Indicator Light on and DTC 0401 stored.
This malfunction is detected when ...
a) An excessively low or high voltage from the sensor is detected by the ECM.
b) The signal from the IATS is inconsistent with the signal received from the Engine Coolant Temperature Sensor.
Possible causes include ...
- Harness or connectors (The sensor circuit is open or shorted.)
- a faulty Intake Air Temperature Sensor
The IATS resistance values should be ...
- at 14 degrees F, 7.0-11.4 Kohms
- at 68 degrees F, 2.1-2.9 Kohms
- at 176 degrees F, 0.27-0.38 Kohms

should i get a new intake sensor?
do i visually check the harness and connectors?
can i check the resistance values with a volt meter?
the temperatures is when car not started or started?
thanks

roger

 

You can visually check the sensor. Just take out the two little brass colored screws that are holding the sensor to the air box. You'll see a wire leading to the sensor. (on top of the box; over it). Examine the sensor once removed - If the little wire is not connected to both ends, it's damaged-you need a new sensor.

The temperature is measured when the engine is running only. Hope this helps . let me know how it goes.

-Paul

 

can anyone provide me witha pic of where this intake sensor is located?i could not find it.thanks

rogroc325@yahoo.com

roger

 

bump,need help please. my ecu is givin me the code and my car does not have the 2 screws like mentioned above.thanks

 

i will take a pic for you tomorrow if i remember. it is right above/behind the airbox the right of the engine bay.

-Paul

 

95-96 and 97-99 have different temp sensors. in the 97 it is attached by a rubber grommet that is plugged in in the tubing right before the airbox

 

Yes, the 99 sensor has a rubber grommet that just pushes into the plastic tubing. It can pop out when someone else messes with your airbox, like the quick change oil places. (happened to me)