VW ACC Deactivated Message – How to Fix the Issue?

It's not uncommon for modern Volkswagen owners to see the "ACC Deactivated" message on the dash. This is the "Adaptive Cruise Control" (ACC) problem that may be triggered by several things in your car. Some of the factors are just temporary but some others will need your efforts to cope with the problem.

ACC deactivated message highlights

• Common reasons:radar sensors issues, camera problems, low voltage, bad weather
• How to fix:clean the radar and camera areas, wait for better weather, check the battery
• Possible consequences:some smart features won't be available
• Priority level:Low
• Can you drive?Yes
• DIY repair:Possible
• Repair price range:$0-$1,000

Reasons for the ACC deactivated message in VW cars

Some of the reasons may be so easy and ridiculous that you won't believe the problem can be solved easily. While some technical things may actually require professional help. I will list the most common issues and give several tips on what you should do.

1. You just manually deactivated the ACC system

There are various ways to activate and deactivate the adaptive cruise control feature in different Volkswagen models. In the majority of cars, you will have the button for this on the left side of the steering wheel. This button turns on and off the ACC.

You may have pressed the button unintentionally and turned off the ACC. Now, when you are trying to use the cruise control, the classic cruise control feature launches (without adaptive features), and the "ACC Deactivated" message appears on the dash.

2. Problems with the engine

The adaptive cruise control feature will not work when there are issues with the engine. I personally had this issue in one of my Volkswagens (the Golf 7th generation in Europe). I had the camshaft actuator error in the ECU and it triggered the ACC problem. It appears that Volkswagen cuts off the ACC once something is wrong with the engine.

Obviously, this is a safety concern because when one of the sensors or actuators doesn't work properly, the vehicle can't fully control the work of the engine and it just turns off the ACC leaving you with the standard cruise control.

3. Radars or cameras are dirty or broken

Your ACC system completely relies on radars and sensors. Those tell the control unit when it's time to reduce the speed or brake automatically, or when it's time to accelerate. Also, the cameras do a lot of other work like watching the road markings and reading the road signs.

But when something is wrong with the sensors or cameras, the problem may be really serious and may block several important functions. For example, the blocked radar may lead to issues with the ACC, automatic emergency braking, collision warning, and collision-preventing systems.

Cameras and radars can be blocked by something like contaminants or some piece of visual tuning. Also, they may be broken and require replacement.

4. Wiring and software issues

These problems are not really common for modern Volkswagen cars. But sometimes, they are still worth checking. The wiring can be corroded after water intrusion. Wires should only be tested by a professional mechanic to avoid wrong diagnosis.

Software issues are more common. The ACC function has its own control unit with some software in it. Of course, as with any software in the world, it can develop a glitch. If you get these problems, you may reset the system or go to the dealership and ask them to deal with it.

Later in the article, I will tell you all about the reset magic.

5. Other issues

You should understand that for the ACC to work properly, your car should be totally good. No issues with brakes or ABS, no problems with the engine or transmission, and all sensors should work properly. Once at least something goes bad, you shouldn't rely much on the ACC.

So, while the car is still new and everything is clean and works fine, you aren't likely to see this message too often. But when the vehicle is older and some units ask for repair sometimes, you will see this ACC warning more and more often.

Sometimes, the actual reasons for the warning are really hard to identify.

What can you do without going to the dealer?

If your vehicle is under warranty, you may still want to go to the dealer and get a free inspection and a free repair. But it sounds better than it actually is due to waiting time and sometimes wrong diagnosis.

So, here are some things that you may actually want to try before you go to professionals:

1) Turn on the ACC

Use the button on your steering wheel to activate the ACC if it was deactivated before.

2) Turn the car off and on

Sometimes, the simple system reset by turning the vehicle off and then on solves the problem.

3) Reset the system by disconnecting the battery

Disconnect the negative terminal on your battery, press the honk to use up all the remaining power, and wait for 5-7 minutes. Then connect the terminal again and see if the problem disappears.

4) Clean the radars and cameras

While radars are pretty hard to find, you may clean their areas (google the location or find it in the driver's manual). Cameras are easy to locate and clean. Sometimes, they can get foggy or dusty.

5) Use the OBD2 scanner

It's worth using a good scanner to see the codes that are active in the ECU and other control modules right now. You may see that some codes are connected to the engine and they may trigger this problem. So, solving all the active problems and codes will obviously help you make your car more reliable.

6) Taking it to a repair shop

If you can't do anything, there is only one option left - take the vehicle in for an inspection. You may use your VW dealership or choose any other repair shop that deals with Volkswagen cars. A professional mechanic will obviously help you locate the problem much faster than you can do it on your own.

What are the signs you should visit the dealer?

Although you can find and solve the problem on your own in the majority of cases, sometimes, professional inspection is still needed. If you fail to catch the problem by doing the things recommended above, you should find a good mechanic.

Usually, the proper inspection tools are available in the dealership and in the repair shops that work exquisitely with Volkswagen cars. Using all-purpose OBD2 scanners is not a good idea as they don't show even half of the errors and codes that are available for professional VW scanners.

So, going to a dealer, at least for pure inspection, is sometimes a good idea. Even though I don't usually recommend repair in the dealership unless the car is under warranty. At least, you can get a good inspection and know what exactly is wrong with the car. Then, you can repair it on your own or just find an independent shop for all the repairs.

Can you drive with the ACC Deactivated message?

Usually, the deactivated adaptive cruise control doesn't change literally anything in the way you can drive your car. If you don't use the ACC function, you may drive and ignore the issue. However several safety features like collision prevention and collision warning may not help you on the way.

Also, the cruise control will only work partially. It will maintain the proper speed but will not brake automatically, keep the proper distance from another vehicle, or read the road markings.

All other functions should be working well and they won't disturb you from driving.

But here are the signs that driving may be dangerous:

• the ACC Deactivated message is accompanied by some warning lights;
• there are other messages popping up one by one;
• you feel that the behavior of your vehicle has changed;
• you identify loss of power or problems with the braking system;
• the ACC Deactivated message intermittently pops up with a beeping sound.

The latter is pretty rare and it shows that there are issues with the software. Maybe, you should check the battery or alternator and see if the voltage in the system is at the proper level.

Other than that, there are no additional risks and you can keep driving.

Final thoughts

I believe the ACC Deactivated message is one of the disturbing issues that make you google the information for the problem. I hope I managed to answer all your questions and helped you solve the issue. If not, please write in the comments about your case and help other Volkswagen owners understand what can go on with their vehicles.