Any error message may easily drive you crazy. You may have just taken your Cruze from regular maintenance or even from some repairs and suddenly you see the “AC Off Due to High Engine Temp” message. Your first thought must be about engine overheating but then suddenly you notice that the engine temperature is completely OK or even low – it hasn’t yet even been heated to its working temperature.
In short, the “AC Off Due to High Engine Temp” message in Chevy Cruze means that the ECU registers some hazardous conditions and tries to make sure that the engine is unloaded. For this, the ECU blocks the AC and some other power-consuming features in your vehicle to reduce power consumption and allow the engine to work in better conditions.
Here’s what I’m going to cover today:
- What does this error message mean and when do you see it?
- Why is the engine cold and you still see this message?
- How can you clear or reset the message and get back the AC?
- Can you drive ignoring this error message in your Chevy?
- Should the Cruze be inspected after it throws this error?
“AC Off Due to High Engine Temp” – let’s see what it means
GM engineers introduced the function to the ECU on Chevy Cruze (and some other models) that would automatically turn off the AC when the engine is in trouble and its temperature rises. Originally, this feature should detect heat in your engine (high coolant temperature) or malfunctioning cooling fan on the radiator and then block the AC.
Why AC, you may ask. The reason for this is that the AC is a power-consuming unit that takes a lot of power from the engine. The AC compressor is connected to the engine by means of the drive belt. When the AC is on, the compressor loads the engine and it loses some power. Of course, this also leads to more heat production in the engine.
So, this is how everything should happen in your Cruze:
- the engine heats over the average working temperature mark;
- the ECU registers overheating and triggers some codes;
- these codes throw the “AC Off Due to High Engine Temp” message on the dash;
- the AC is turned off or just blocked and you can’t turn it on now;
- the function will be active till the temperature drops or you turn off the engine.
So, this is a certain feature that is aimed to save your engine from additional loads when things are not so good. And it sounds cool but does it work that way?
Situation 1: You see the “AC Off” message and the engine is hot
This is actually how it works. Once you see this message, you should pay attention to the engine temperature gauge. If the needle is not in its usual position (somewhere in the center of the gauge), the engine may have problems with its working temperature. If the engine overheats, driving it further is not recommended.
Here’s what you should do in this case:
- Immediately find a safe place to stop your vehicle.
- Turn off the engine as soon as possible.
- Open the hood to let the engine cool down faster.
- After at least 15 minutes, turn on the ignition for 10 seconds and look at the temperature gauge.
- You can keep driving after the engine temperature falls below the central mark on that gauge.
After you start the engine again, the “AC Off Due to High Engine Temp” error message should not bother you anymore. Also, the AC should be functional and ready to cool down the air in your Cruze.
But if this happens again and the engine overheats, you should find the reason why this happens. Maybe, the coolant level is low, or maybe the cooling fan on the radiator is broken and doesn’t turn on when needed. Driving an overheated Cruze is not something you will want to do.
Situation 2: You see the “AC Off” message but the engine is cold or normal
In this case, I can bet this is the problem with the engine temperature sensor. I heard different opinions like it can be a thermostat or no coolant in the system. Yes, if there is completely no coolant, this can happen but I still see no logic in this because the ECU triggers this AC-Off function based on the readings of the engine temp sensor.
If there is no coolant, the sensor will have low-temperature readings. If the thermostat is not working, the engine temperature sensor will still show the temperature because it’s located in front of the thermostat and will still show the proper readings.
So, my guess is the problem with the engine temperature sensor. Here’s what you should do:
- stop the vehicle carefully and safely;
- if it can potentially be overheated, let it cool down;
- if the engine is cold or has a normal temperature, you may continue driving ignoring the message;
- visit the nearest dealership or the trusted repair shop and ask for checking the engine temp sensor;
- buy a sensor and install it on your own or have it installed in the shop.
The aftermarket sensor is quite cheap – something like $15. Even an OEM sensor for your Cruze will not cost you a fortune. Also, for changing it, you will not need to drain the coolant or take off the thermostat. In most cases, you can do this on your own. Also, you may choose to pay something like $50 to an independent repair shop and they will do this task for you.
Once the engine temperature sensor is working properly, the ECU will immediately get the correct readings of the engine temp and will allow you to use the AC.
Situation 3: You see the “AC Off” message, the engine is at normal temp, and the sensor is working
Now, this is kind of some mystery! You see that the sensor is working because you see the needle on the engine temperature gauge moving the way it usually does. The engine is not hot, it’s working just as it should and you’ve just checked the coolant level – everything is fine.
Why is this error message getting on your nerves then? I have several guesses that you will need to check with your Cruze:
- Crazy ECU. Unfortunately, GM ECUs may malfunction pretty often because of water damage, temperature damage, or some physical impact. You will need professional help if you find out that the ECU in your Cruze is malfunctioning.
- Alternator or battery problems. If you see this error once you turn on the ignition and the engine is off, check the battery. Low voltage in your battery may drive the ECU mad. Also, the alternator or the voltage regulator may be malfunctioning and causing this problem.
- Software issues. Your ECU may not only have hardware problems like water damage or something. It may need a hard reset because its software started glitching and now throws random codes and does some crazy things.
- Engine temperature gauge is faulty. This is obviously not a common problem. But it may still happen that the gauge is just not showing you the real situation with the engine temperature and the engine is overheating.
To locate such tricky problems, you will need professional help or at least a good OBD2 scanner that you can connect to your vehicle and read some codes in the memory of the ECU, provide the Cruze with some electronic tests, etc.
Clearing the “AC Off” error message
First of all, you shouldn’t drive the Cruze when you see this message and ignore the hazard to your engine. If it actually overheats, things may fast escalate and your engine will fail. After bad overheating, you may find it easier to buy another engine than to repair the one that failed.
To clear this code, you may try the following:
- Stop the vehicle, turn off the engine, wait 5 minutes, turn it on again, and see if something changed.
- Disconnect the battery from the Cruze for 5-10 minutes. First, take off the cable from the negative terminal, then from the positive. Connect the positive first, then the negative.
- Use your OBD2 scanner to clear the code. But it will most likely reappear after some time if the reason is not fixed.
- Repair the initial problem and the code will clear itself without your help.
The best way is to choose the last way. This will help you save the engine from severe overheating and also let you spend much less on repair in the future. If you follow all the tips given in this article, you will avoid bad problems and will most likely be able to solve the issue with just minimal investment.
Final thoughts
When it comes to your Chevy Cruze, the car may surprise you with some exotic error messages. The “AC Off Due to High Engine Temp” is one of them. Hundreds of Cruze owners see this message every day and they just don’t understand how to act. After reading this article, you now know what it means and what you can immediately check.
Remember that if your engine actually overheats, you should drive it with breaks to let it cool down. If there is no coolant or the level is low, you can add water if there is no access to high-quality coolant. Don’t forget to clean the cooling system before changing the coolant-water mix.
If you still have any questions or want to tell us about your experience, just write in the comments below.