Air conditioning (AC) system in your Toyota Highlander is crucial in keeping you cool and comfortable during your travels. However, if you have noticed that your car’s AC system is not working, it may be a sign of low refrigerant levels.
Refrigerant is a vital component of the AC system responsible for absorbing heat and cooling the air circulated inside your vehicle. You may experience various symptoms when your Toyota Highlander’s AC system lacks refrigerant.
These symptoms include weak airflow, reduced cooling, unusual noises, and unpleasant odors. If you are experiencing any of these symptoms, recharging the refrigerant in your Toyota Highlander’s AC system may be necessary.
To recharge the system, you will need to locate the low-pressure port, attach the AC recharge hose, and add the appropriate amount of refrigerant.
To know more in-depth information about symptoms of low AC refrigerant in a Toyota Highlander and how to recharge, keep reading the entire guide.
What Does Low AC Refrigerant Mean in Toyota Highlander?
Low AC refrigerant in a Toyota Highlander means that the refrigerant level in the air conditioning system is lower than it should be. A leak in the system or normal wear and tear can cause this.

When the refrigerant level is low, the air conditioning system may not cool the vehicle’s interior properly or work at all. It’s important to have the system inspected and repaired by a qualified technician
This is because running the air conditioning system with low refrigerant can damage the compressor and other components, leading to more expensive repairs down the line.
Types of Refrigerants Used In Toyota Highlander
The Toyota Highlander uses different refrigerants depending on the model year and region where it was sold. Older models may use R-134a refrigerant, which is a hydrofluorocarbon (HFC) that has a low ozone depletion potential (ODP) but a high global warming potential (GWP).
Newer models may use a more environmentally friendly refrigerant such as HFO-1234yf, which has a lower GWP than R-134a. HFO-1234yf is a hydrofluoroolefin (HFO) and is classified as a fourth-generation refrigerant, as it has a very low GWP and does not contribute to ozone depletion.
Symptoms of Low AC Refrigerant in a Toyota Highlander
When the AC refrigerant is low can result in various problems that can affect the performance and comfort of the vehicle. Here, we will outline some common symptoms of low AC refrigerant in a Toyota Highlander.
Poor Cooling Performance
One of the most obvious symptoms of low AC refrigerant in a Toyota Highlander is poor cooling performance. If the refrigerant level is low, the AC system will struggle to cool the air effectively, and you may feel warm or hot air blowing out of the vents. This can be particularly noticeable on hot days, where the temperature inside the car can rise quickly if the AC system is not working properly.
Strange Noises
Another symptom of low AC refrigerant in a Toyota Highlander is strange noises coming from the AC system. The compressor in the AC system relies on the refrigerant to function correctly. If the refrigerant level is low, the compressor may start making unusual noises, such as grinding or hissing. These noises may be more noticeable when the AC system is first turned on or when the vehicle is idling.
AC System Cycles On and Off Frequently
When the refrigerant level is low, the AC system may cycle on and off more frequently than usual. This is because the compressor is designed to shut off when the refrigerant level is too low and turn back on when the level is back to normal. This can cause the AC system to cycle on and off more frequently than usual, which can be annoying and inefficient.
Ice on AC Components
Low refrigerant levels can cause the AC system’s evaporator coil to freeze. This can result in ice forming on the coil and other components in the AC system. When this happens, the air conditioning system may stop working altogether, and you may notice that the air blowing out of the vents is not as cool as it should be. This can also put additional strain on the compressor, which can lead to further problems down the line.
Unusual Smells
Another symptom of low AC refrigerant in a Toyota Highlander is unusual smells from the AC system. When the refrigerant level is low, the AC system may not be able to properly remove moisture from the air, which can result in a musty or moldy smell from the vents. This can be especially noticeable when the AC system is first turned on or when the vehicle has been sitting for some time.
Causes of Low AC Refrigerant in a Toyota Highlander
Low AC refrigerant in a Toyota Highlander can be caused by various factors. Some of the most common causes include.
- Refrigerant Leaks: Refrigerant leaks are the most common cause of low AC refrigerant in a Toyota Highlander. Over time, the seals and hoses in the AC system can wear down, and refrigerant can leak out of the system.
- Normal Wear and Tear: Even if there are no visible leaks in the AC system, the refrigerant level in a Toyota Highlander can naturally deplete over time due to normal wear and tear.
- Damaged Compressor: The compressor is an important component of the AC system in a Toyota Highlander, and if it becomes damaged or worn, it can result in low AC refrigerant.
- Incorrect Refrigerant Charge: Low AC refrigerant in a Toyota Highlander can be caused by an incorrect refrigerant charge. If the AC system was not charged with the correct amount of refrigerant when it was last serviced, it could result in low refrigerant levels and poor cooling performance.
How to Recharge AC Refrigerant in a Toyota Highlander?
Recharging the AC refrigerant in a Toyota Highlander is a straightforward process that can help restore the AC system’s cooling performance. Here are the steps to follow:

1. Gather the Necessary Equipment
To recharge the AC refrigerant in your Toyota Highlander, you will need an AC recharge kit, which includes a can of refrigerant, a pressure gauge, and a hose. You will also need safety goggles and gloves to protect yourself during the process.
2. Locate the Low-pressure Port
The low-pressure port is located on the AC system, where you will attach the recharge hose. In a Toyota Highlander, the low-pressure port is typically located near the vehicle’s passenger side firewall.
3. Connect the Recharge Hose
Once you have located the low-pressure port, connect the recharge hose. Follow the manufacturer’s instructions for attaching the hose and ensure that it is securely in place.
4. Add the Refrigerant
With the hose securely attached, start the engine, and turn on the AC system. Then, follow the instructions on the AC recharge kit to add the refrigerant to the AC system.
You should monitor the pressure gauge as you add the refrigerant, and stop adding refrigerant when the pressure reaches the recommended level.
5. Disconnect the Hose and Check the AC System
Once you have added the correct refrigerant, disconnect the recharge hose from the low-pressure port. Then, check the cooling performance of the AC system to ensure it is working properly.
If the AC system is still not functioning correctly, it may be necessary to take your Toyota Highlander to a qualified technician for further diagnosis and repair.
Final Verdicts
Low AC Refrigerant in a Toyota Highlander can cause various issues, from reduced cooling to strange noises. To prevent such problems, it is important to check the refrigerant level regularly and recharge it if it is low.
The process of recharging the system is straightforward and can be done at home with the right tools and the right refrigerant. However, you should ensure that all safety protocols are observed during the process.
Taking proper care of the refrigerant in a Toyota Highlander will keep the air conditioning system running smoothly and efficiently.