How Do You Reset The AC On a Chevy Avalanche? (With Pictures)


On most early 2000s general motors vehicles, including Chevy Avalanche, the AC loses calibration if you have disconnected the battery or replaced any heater control component like an actuator. So, if you have had any other issues and you simply had to disconnect the battery, you can expect some issues with the AC.

However, before you take your Chevy Avalanche to a mechanic, try to reset the AC first. The procedure is pretty simple and worth trying. This works for most GM vehicles, including the Chevy Avalanche.

How Do You Reset The AC On a Chevy Avalanche

How Do You Reset The AC On a Chevy Avalanche

The AC reset on a Chevy Avalanche takes about five minutes out of your time. It is definitely worth trying before you take your vehicle to a repair shop. Here is how to reset the AC on a Chevy Avalanche, and most GM vehicles.

The AC calibration of the vehicle will take about five minutes in total and will require the vehicle to run for about two minutes. So, make sure that you park your vehicle outside, or keep the garage doors open.

1. Turn the key on

The first step is to turn the key on. When you do this, the AC display will show a random temperature. It is usually at 60 degrees Fahrenheit. Regardless of what the AC display is showing, move on to the next step.

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2. Turn the auto control on the AC

This step is very important. You need to set the AC on auto control. When the AC is set on auto control, the system takes over and automatically controls the cabin temperature, airflow, and the overall air distribution inside the cabin. Depending on what’s wrong with your AC, it might blow hot air, not blow at all, or partially blow some cold air.

If it’s blowing too hot, you can roll down the windows or open the doors.

3. Turn the ignition off

Once you set up the AC on auto control, turn the ignition off. Make sure that the AC stays on auto control. This is because the next time you will start the engine, the AC will automatically start. This is a vital part of the calibration process.

4. Locate the fuse box

How Do You Reset The AC On a Chevy Avalanche

The next step is to locate the fuse box. On most GM vehicles, including the Chevy Avalanche, the fuse box is located under the hood, on the driver’s side. It is a plastic box that might or might not have the ”Fuse and Relay box” written on top of it. Remove the cover of the fuse box and store it safely.

5. Locate and remove the HVAC battery fuse

How Do You Reset The AC On a Chevy Avalanche

At first, it might look confusing. But, trust me, it really isn’t. Once you remove the cover, you will notice that there are markings on the inside of the fuse box cover. It says which fuse is for what and you really can’t go wrong. At this point, you need to locate the HVAC battery fuse. It is a 10 amp fuse with red color.

Remove it and inspect it. If the fuse is blown, it is a good time to replace it with a new one. But, if it’s good just remove it and store it safely.

Fuses are pretty cheap, so it is always a good idea to have a brand new one at hand.

6. Wait for sixty seconds and install the fuse

Once you remove the HVAC battery fuse, wait for about sixty seconds. At this time, the HVAC ECM which is the brain of the AC will wipe off the memory. If your AC is not blowing as it should, it means that the ECM has the wrong data stored. This is why calibration is needed. Once the old data is wiped off, the next time you start your vehicle, the AC will be restored back to factory mode.

7. Start the engine

When you start the engine, the AC auto system should come on at 74 degrees Fahrenheit. This temperature is set as factory and it means that the AC is self-resetting. At this point, the actuators are going to open and close and blow air through the dash vents, defrost, and floor. This is also a great time to check how each vent is performing.

It is very important that you do not touch anything for about sixty seconds.

8. Shut the engine off for ten seconds and restart it

Once the engine has been running for a minute or so, shut the engine off. The engine should be shut off between ten and thirty seconds only. Do not go over thirty seconds. So, about ten to fifteen seconds in, start the engine back on.

There isn’t really information on why you should only keep the vehicle shut off between ten and thirty seconds. I guess that after thirty seconds, the HVAC ECM will pick up the last data(the wrong one) and your AC will again perform poorly.

9. Test the AC

Start the vehicle and test the AC. If the AC on your Chevy Avalanche or any GM vehicle needed calibration, at this point, it should be fixed. Now is a good time to test the AC. Try different vents, defrost, and floor and see how it works. Test the fan speed as well.

When To Reset The AC in Your Vehicle

If your AC was working one minute and just stopped working, it can be frustrating. Taking your vehicle to a repair shop can cost a lot of money. However, this isn’t always the case. Before you take your vehicle to an HVAC expert, there is something that you can do by yourself and potentially save a lot of money.

If your AC is running but not cooling your car, if your AC is blowing on the driver’s side, but not on the passenger side, or if your AC isn’t running on dashboard vents, defrost, or floor, you can perform an AC reset(calibration).

Often when car owners disconnect their car batteries, the AC stops working. If this has happened to you, you should first try and reset the AC in your vehicle before going to the repair shop.

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Hi there. I am a certified Automotive Service Excellence (ASE) mechanic since 2018 and a car detailer for 10 years.

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