Reset Ambient Temperature Sensor: The Vital Guides!

An ambient temperature sensor allows the AC or Heater to maintain a normal temperature inside. Besides, one needs to replace or reset ambient air temperature sensor when it goes bad.

The Basics of An Ambient Air Temperature Sensor

You may now wonder what does an ambient air temperature sensor do. And here is the answer for you.

An ambient temperature sensor may sound like a strange term for the first time. But your automobile temperature system is incomplete without it. 

This sensor plays an important role to make our rides comfortable. It keeps an eye on the car’s cabin temperature. The sensor monitors temperature from inside the car as well as out.

With the purpose of this part, let us prepare the vital guide to repair and reset an ambient temperature sensor.

How To Reset Ambient Air Temperature Sensor?

Automobiles have automatic AC systems and temperature display things these days. 

The gauge displays the outside temperature to that of the cabin’s temperature. And that is when the ambient temperature sensor comes into the picture. 

The sensor examines the outside temperature info and presents it on the driver’s display. If in case the sensor goes out of order, one needs to replace it for sure.

The ambient air temperature sensor controls the automation of AC systems. It also supplies the exact reading of the outside temperature to the driver display. 

Overall, an ambient air temperature sensor replacement is necessary to keep up the vehicle cabin temperature.

1. Find The Sensor

To replace or reset ambient temperature sensor, make sure you know the ambient air temp sensor location. The sensor is present at the very front of the engine. It is right in front of the radiator or the engine bay.

There is a certain reason behind the sensor location at this place. It is to keep the sensor away from engine heat. The reading will not be accurate if there is engine heat and outside temperature both around the sensor.

location of ambient air temperature sensor
There is a certain reason behind sensor location at this place (Photo: anpadeh)


2. Detach The Battery

It is necessary to remove the power supplies before working on electrical appliances. Detaching the car battery before you reset ambient air temperature sensor is a crucial safety factor. 

One might get into serious trouble by avoiding the instructions. The expert maintenance tips state that you should never touch electrical systems without cutting power from the battery.

3. Remove The Sensor

Remove the sensor once you are done with the battery and sensor location thing. There are special plastic terminals to attach the sensor to the wiring. 

You can locate the plastic clip that fixes the terminal to the automobile and wiring.

Disconnect the sensor without pulling extra force on the wires.

You may end up damaging the entire setup and wiring. Some automobiles connect the sensor with a screw as well. So unscrew it first and then remove it properly.

4. Reset Or Replace The Sensor

You can reset ambient air temperature sensor after removing it. You have to replace it if there is a sensor malfunctioning. Or find the reset button on it. 

There are Mode buttons on the sensor in some cars that allow you to do so. Or clean the sensor and put it back in place and then check the reading. It works sometimes.

how to reset coolant temp sensor
You have to replace the sensor if there is sensor malfunctioning (Photo: tractionlife)

Symptoms Of A Bad Ambient Air Temperature Sensor

After knowing how to reset ambient air temperature sensor, we will quickly scroll through some faulty ambient temperature sensor symptoms

You’ve probably known about all this. But in case there are any signs you are not sure about, this piece of information below may be helpful.

Inconsistent cooling effect

The first bad ambient air temperature sensor symptoms we’d like to mention is an up-and-down coolness inside the cabin. 

Because your ambient temperature sensor plays a direct part in your AC system’s automatic activities, it may interfere with its capacity to maintain a cool and pleasant cabin temperature.

If your AC reads the ambient and cabin temperature sensors and they provide a false signal, your auto AC mode will not function.

Poor fuel economy

Inaccurate readings from your ambient temperature sensor might cause your onboard computer to provide an inaccurate signal, resulting in poor fuel pressure control.

The failing signal indicates that your signal is cold, which causes more gasoline to be utilized to heat the engine, affecting your performance and fuel efficiency.

Check Engine Light on

If you’ve read any of our other articles, you’ll know that a check engine light is rather common. It is very frequent in older cars and can signify a wide range of problems, which is inconvenient.

If you detect a problem with your ambient temperature sensor, your check engine light may temporarily illuminate to warn that the sensor circuit is faulty and has to be repaired.

outside temperature gauge for car
The check engine light can turn on when there’re problems with the ambient air temperature sensor. (Photo: Greg’s Japanese Auto)

Engine overheating

Your engine cooling fan ensures that heat is evacuated from the engine coolant and that the engine temperature remains safe. This, however, will not occur if the ambient temperature sensor fails.

The electrically driven fan operates on a signal from the computer, and this signal may not occur when necessary, causing the engine to overheat. However, this isn’t always the case because some vehicles have a separate coolant temperature sensor for the fan.

Black smoke from exhaust

Pay attention to your exhaust smoke, since black smoke from exhaust indicates that too much gasoline is being burned in the exhaust pipe. This is because the ECM may fail to provide the proper air/fuel mixture, interfering with your vehicle’s natural combustion process.

How to Bypass an Ambient Air Temperature Sensor

If you’re well-versed with the workings of your car, you might want to investigate bypassing your ambient temperature sensor for a more permanent solution.

However, we do not advocate doing so unless you are very sure. As with any other component of your vehicle, changing or utilizing aftermarket components may result in premature wear or problems, so consider carefully before proceeding.

You may utilize this to your advantage in some vehicles with applications such as FordPass to bypass the ambient temperature sensor. You may also use a scan tool to ensure that the sensor is not malfunctioning or displaying any errors.

Let’s take a deeper look at the 3 approaches to bypass the ambient temperature sensor.

#1 Method

  • Open battery and locate the sensor
  • Cut red and black wires from the battery
  • Attach one cable’s end to a battery
  • Connect the other to the battery’s terminal

#2 Method 

The second option is simple and straightforward, but you should always use caution while working near and with your vehicle’s batteryBegin by covering the ambient temperature sensor in paper, then put in the battery and operate it normally.

#3 Method

Applying roughly 10ml of liquid crystal to a tiny glass capillary will form a clear window through which infrared rays may flow, and the phase will change depending on the ambient temperature.

ambient air temperature sensor circuit high
You can bypass an ambient air temperature sensor by following these simple methods above. (Photo: tpicard)

FAQs On Ambient Air Temperature Sensor

  1. Why is the car reading the wrong temperature?

Instead of a thermometer, your automobile has a thermistor. Car thermistors provide an inaccurate picture of the outside temperature. This is due to the thermistor being subjected to re-radiated heat from the road surface.

  1. Does ambient air temperature sensor affect AC?

The ambient temperature sensor, also known as the ambient temperature sensor switch, is one of the principal sensors that plays an important role in the functioning of the AC system

Vehicles in high heat or cold will demand much greater effort from the HVAC system to both cool and heat the cabin.

  1. Does ambient air temperature sensor affect engine?

The temperature of the ambient air should not affect engine efficiency or fuel consumption, but it will affect total power output. Do not mix up efficiency with power output.

The Final Words

That is all you need to know about how to reset ambient air temperature sensor. Hope the info was helpful! 

Check your user handbook before attempting any of the ways to confirm that the operation is safe for your truck. If the technique does not work, you may also inquire or consult specialists for advice.

For more car maintenance tips, follow Car From Japan today!