How to test an Air Temperature Sensor
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- čas přidán 24. 07. 2024
- Air Temperature Sensors are another of the 'family' of electronic sensors used by modern Electronic Fuel Injection systems. The car's computer (ECU) needs to know how warm/cold the incoming air is and a variable resistor is used in this component to give the ECU a variable voltage signal based on the air's temperature.
This information is included in its calculations when working out thinks like ignition timing and how much fuel to inject (rich or lean mixture).
Often symptoms like poor starting and excessive fuel consumption can be caused by the ECU receiving an inaccurate signal from the Air Temperature Sensor.
Sure, we can use a code reader to see what fault codes (if any) have been recorded but those fault codes only relate to 'circuits' rather than components.
Knowing how to actually bench test this sensor is a far more accurate way of determining if it is working correctly or not. If it is then you can eliminate it from your investigations, if it is faulty then it will need to be replaced, though there may be other faults too so all wires relating to that circuit should also be checked, just in case there may be a short circuit somewhere (insulation has worn through and the wire has grounded) or maybe a break in the circuit too - anything is possible!
In this video I'm checking an Air Temperature Sensor from a 1996 Toyota Rav4, its a 3 door version 4wd with a manual gearbox and is fitted with the 3S-FE 2 ltr, 4 cylinder petrol engine. The method of this test does apply to almost all Air Temperature Sensors, however, you will need to source the specification data for your specific Make, model & year of car as the output voltages can vary, especially between manufacturers.
If you have any questions or comments please leave them in the comments section below...
Andy Mechanic! - Auta a dopravní prostředky
Hell yeah. Just what I was looking for! A video of how to bench test the iat sensor and without all that added mumble jumbo these other channels will go through and not explain how to test it and what main symptoms the car will have if the sensors should fail or have damage on it. Thanks a bunch brotha!
Thankyou hotter less resistance. Like the signal tester
factory tunes are always lean due to emission test. So probably you can plug in some resistor to the sensor to change its resistance to fool the ecu to pump in more fuel slightly to improve acceleration.
Mine is on a 95 jimmy mine at outside temp shows like 1.7 and when I put my ac on it it dropped to 1.4 1.5 ohms does that sound like its working right to you ?? Can't pull any codes because its a screwy obd1.5
Great video, thank you..
The video is really informative and nicely explained ✨👍
Can a dirty air filter cause the air temp sensor to send wrong readings to the computer?
No, in my opinion it will have no effect on air temp readings. Cheers Andy
@@AndyMechanic Okay. Thanks, Andy!
@@AndyMechanic what about no air filter at all
Great video
My special stirring device has a flat end on it...
Will this experiment still work???
Haha! Sure will :-)
Would a bad sensor cause a motorcycle not to idle ?
Yes, if air temp signal indicates wrong temp ECU will give incorrect mixture. Same for coolant temp sensor too.
Cheers Andy
Will it cause the engine to cut out ?
Unlikely, though it will affect fuelling, engine could run too rich or too lean depending on sensor output, in extreme circumstances it could cause the engine to stall - for example sensor reporting air is very cold when in fact it's very hot.
Hope this helps
Andy
@@AndyMechanic I tested it, values were under spec in the FSM. I ordered a new one.
I'd rather just spend the 20 bucks and buy a new one rather than goin through the hassle of settin' up this Mr wizard junior science project....😅
Lol!
@@AndyMechanic Thanks for being a good sport. I was just messin' around. Great video and I know you put a ton of time and effort into it. It's not easy producing clear, concise content such as this. Nice job! Kudos
Just spend the 15 bucks and replace it!
Great video thank you so much.