Does Ambient Temperature Sensor Affect AC?

Modern cars come with high-tech heating and cooling systems that are very effective at creating and maintaining cozy interior temperatures for the users.

You may wonder, can the ambient temperature sensor affect your AC system? That's why we gathered helpful information for you regarding this topic, and here is what we found.

Since it affects how automatic AC systems work, ambient temperature sensors can impact troubled AC systems by lowering their capacity to chill the car.

But how do you know if you have a failing ambient temperature sensor? Keep reading as we answer that question and give you ways to deal with it.

We'll also discuss its function, its importance, and where to locate such a sensor. We'll also tackle if you can reset it and how to replace the sensor.

Air conditioner on car dashboard, Does Ambient Temperature Sensor Affect AC?

What Is An Ambient Temperature Sensor And How Does It Work?

The ambient air temperature sensor is a negative temperature coefficient (NTC) sensor that provides temperature information to the automatic or semiautomatic temperature management system.

With rising ambient air temperature, the NTC sensor's resistance falls. To regulate temperature and blower speed, the computer uses this input in addition to other in-car temperature sensors.

The sensor gives the HVAC systems in the car information they may use to regulate the temperature inside.

Temperature readings from outside the car are likewise offered to the passengers by the sensor. Driving in temperatures below freezing or near freezing calls for using this information.

Where Is The Ambient Temperature Sensor Located?

SUV headlight with grill guard

This sensor is usually located at the front of the car, specifically the bumper where the air intake grilles for the engine are situated.

What Are The Signs Of A Failing Ambient Temperature Sensor?

Here are some of the most typical signs that you might experience that the ambient temperature sensor is faulty or damaged.

Inefficient Fuel Economy

The onboard computer may get an inaccurate signal due to a malfunctioning ambient temperature sensor, which may lead to poor fuel pressure management.

For instance, if a sensor isn't working correctly, it can signal that the engine is cold when it isn't, requiring extra fuel to warm it fast.

The fuel economy and engine performance suffer as a result.

Engine Light Turns On

Check engine light

One of the first symptoms you'll see is a brief check engine light illumination.

A malfunctioning sensor causes the check engine light to come on, alerting the driver that the car needs to be repaired.

Exhaust Emits Black Smoke

Air pollution crisis in city from diesel vehicle exhaust pipe

The ECM may over-enrich the fuel mixture to the extent that it interferes with combustion, causing it to stall due to an inaccurate temperature indication.

The exhaust pipe will burn any extra fuel, producing a thick, dark cloud of smoke.

Engine Overheating

Automotive engine overheating on the road

The radiator grille-mounted engine cooling fan is in charge of eliminating heat from the engine coolant.

The computer's signal regulates the electrical operation of this fan. The fan might not turn on if it gets a false signal, leading to the engine overheating.

Bad Idle

The fuel mixture will change appropriately if the ambient temperature sensor is malfunctioning.

When the car is moving slowly, this will result in other power losses and odd behavior, as well as the engine shaking or vibrating.

AC Auto Mode Not Operating

Most modern cars include an automatic climate control setting that enables the vehicle to set and manage the temperature for you.

Simply by reading the data from the cabin and ambient temperature sensors, the air conditioning system will continuously cycle on and off as needed to keep the inside cool.

The system won't function if the ambient temperature sensor malfunctions since it lacks a reference point for automatic computations.

Unreliable Cooling

Inconsistent cooling is another sign of a defective or failed ambient temperature sensor.

The ability of the AC system to operate automatically is directly dependent on the ambient temperature sensor; therefore, when it malfunctions, the system may be unable to chill the vehicle.

The AC system may struggle to keep the car cool and pleasant if the ambient temperature sensor malfunctions or transmits an inconsistent signal.

Erroneous Temperature Gauge Reading

Temperature gauge on the dash board of a car

An erroneous temperature reading on the car's thermometer is one of the more glaring signs that a sensor is malfunctioning or defective.

Most automobiles have some type of interior display that shows the outside temperature, typically determined by the ambient temperature sensor.

The sensor should be replaced if the reading on the gauge or indication is off by more than a few degrees since the inaccurate reading could prevent the AC system from operating as it should.

Can You Reset The Ambient Temperature Sensor? [And How To]

Yes, you can! Before replacing your faulty ambient temperature sensor, experts recommend resetting it first. To do this, you can follow these steps.

  1. Finding the sensors' location to access the gadget quickly is the first step in resetting them.
  2. Remove the battery before using any electrical equipment and unplug the power source. Take caution because the wiring or the system as a whole can be affected.
  3. The most crucial step is to reset the device, which comes next. On most ambient temperature sensors, locate and hit the reset button.
  4. After unplugging the device, you might try cleaning it because dust might affect how well the ambient temperature is measured.
  5. Reattach the clip or screw it back into place, then assemble the device as before. You should check the sensor after connecting the charger.
  6. Attempt to synchronize the information from any real-time weather program.

What Tools And Materials Do You Need To Replace An Ambient Temperature Sensor?

Here are the tools and materials you need to gather before starting your sensor replacement task:

Safety Gloves

Perfect for use with power tools, motorcycles, utility personnel, standard construction, etc.

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Plier Kit

This will help you cut, connect, and secure the sensor wires in place.

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Replacement Sensor

Of course, this part is the most important of all. You need a new sensor to replace the old one.

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Socket Set

Regardless of your skill level, you will ultimately need to utilize a socket set to remove or tighten a bolt or nut.

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Safety Goggles

This will help you protect your eyes from any flying debris.

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How To Replace A Damaged Ambient Temperature Sensor

If resetting won't work, then it's time to replace your ambient temperature sensor. There are two parts to doing this:

  1. Damaged Sensor Removal
  2. Sensor Replacement

Part 1: Damaged Sensor Removal

This part focuses on how to remove the damaged sensor. You can follow these steps to do this:

  • Disconnect the battery's ground cable. Cutting electricity to the battery is essential for safety when working on any kind of electrical equipment in your car.
  • Find where your sensor is located. Usually, manufacturers strive to make these sensors accessible while keeping them safe. You might need to remove all or a portion of your front grille to access this sensor.
  • The sensor should be removed from its mounting bracket by pulling, twisting, or unclipping. After removal, check the sensor for any significant damage.

Part 2: Sensor Replacement

After successfully removing the old sensor, it is time to replace it.

  • In the same manner you removed the previous sensor, install the new one. The replacement sensor should snap, screw, clip, or bolt on and fit identically to the previous one.
  • Connect the new sensor with the existing wiring connection. Similar to the previous component, the new sensor should accept the wires already in place.
  • You can then reattach whatever portion of the grille or radiator covers you detached to gain access to the sensor after plugging it in.
  • It will take some time for the sensor and the computer to connect. Once it has warmed up, adjust the temperature in your car so that it is either lower or higher than the outside temperature. Test the automatic temperature controls while driving the vehicle if required. This exam is also available in park mode.

In addition, here are some tips you have to take note of when you replace this sensor:

  • The front of the car has ambient air temperature sensors placed in a sensitive area. This sensor may have problems if the grille or front bumper are damaged.
  • Some recent replacement components have slightly different designs and might not appear identical. They should, however, plug in and fit into place precisely the same as the previous sensor.
  • Never try to push a wiring terminal into its match. However, damaging them and having to wire a new terminal can be time-consuming and expensive. They can be stubborn. They ought to lock into place and remain there. When using the terminals, ensure they are in good shape.

Final Thoughts

Manufacturers make an effort to use the same sensors for a variety of tasks. The performance of your automatic heating and cooling systems might be affected in various ways depending on the ambient air temperature sensor.

The readings on your exterior temperature driver displays may also be impacted.

If you enjoyed this post, please check out these other articles:

Car AC Evaporator Freezing Up - What To Do?

Why Does My Car Air Conditioner Smell Like Rotten Eggs?

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One comment

  1. I own a 2015 Opel Mokka 1.4T auto. Would the faulty. ambient temperature sensor be the reason that that an ice on road warning comes up as well as a temperature reading of between -12deg and-32deg….therefore not allowing the aircon to kick in….the real outside temperature was in the region of 30deg C

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