OBD2 Has Power but Won’t Connect: What to Do? (Explained!)

The OBD2 plays an essential part in a car’s system due to many reasons. For instance, it is a vehicle’s reporting capability and self-diagnostic function. In short, this part gives the owner or the mechanics the current status of your car’s system. For this reason, your OBD2 must connect. So, you may ask:

If my OBD2 has power but won’t connect, what should I do? Most OBD2 won’t connect because it has no power. However, if it has power but won’t connect, you may want to check its connection to your entire system. In most cases, it can be a cabling problem, or the OBD2 itself isn’t working. Thus, you’ll have to take it to a mechanic soon.

The OBD2 is a feature that helps a lot in diagnosing your car. However, once it malfunctions, it can also be a pain to deal with, especially if you have no time to check it. For this reason, you’ll need to understand how it works and why it happens.

In this article, you’ll see an in-depth take on OBD2 and the possible problems it may have on your car, predominantly on its connections. This way, you can better grasp how it works and how you can deal with it if it ever happens to you.

Without further ado, let’s get into it!

OBD2 Has Power but Won't Connect

Why Is My OBD2 Port Not Communicating?

Non-communication issues happen in OBD2 ports, and it can be a hassle if you experience such. However, you can check on three leading causes of such issues. 

If your OBD2 port is not communicating, you probably experience one of the following issues:

Blown OBD2 Fuse

A blown-out fuse is one of the usual reasons why an OBD2 port isn’t communicating. Even if it has power, it won’t communicate if the fuse blew. 

Thus, one of the best ways to examine your OBD2 is through the cigarette lighter. If your cigarette lighter fuse gets blown out, likely, your OBD2 won’t communicate as well. Thus, if it starts to communicate, you can start testing out your cigarette lighter. 

In most vehicle units, the vehicle’s mechanism for communicating with testing equipment is powered by a particular channel as the cigarette lighter.

If the interior of the fuse is dark as if it were a blown light bulb, or if the power lines within the fuse are burned apart and don’t attach, then the fuse is defective.

Damaged Data Link Connector (DLC)

The data link attachment (DLC) is broken or interfered with, making it impossible to connect to the onboard diagnostic (OBD) computer. 

For instance, the DLC might be damaged or burned, you could use the DLC to charge a gadget, or the DLC could be plugged in.

The data link connector is responsible for transmitting data or information from the system to the OBD2 port. Thus, it’s also possible that the data link connecter got damaged or is malfunctioning if the OBD2 port fails to communicate.

In general, such problems need repairs from a technician who knows his way on these parts.

Improperly Installed Aftermarket Systems

Some distributors of aftermarket systems, such as radio systems, surveillance systems, communications systems, and so on, are powering the stereo or other third-party gadgets via the DLC or OBD2 port wire harness. 

It is considered manipulation, and it may prevent the car from communicating with the OBD2 testing equipment during the examination.

In short, if both the DLC and the fuse have no problems, this one is likely the reason why your OBD2 won’t communicate.

What to Do When Your OBD2 Won’t Connect?

If your OBD2 won’t connect or communicate, you may want to do some things in response to this matter. For instance, it may help you deal with the issue by doing these things:

Check your car’s cigarette lighter.

As I mentioned earlier, a blown-out fuse can be a reason why your OBD2 won’t communicate despite having power. Thus, you may want to check your car’s cigarette lighter. This way, you can check the fuse and change it if you see that it blew out.

Check the wiring of third-party systems.

Since the third-party tools and accessories can cause issues if not installed properly, you may also want to check the wiring of such accessories if you have them.

By checking these connections, you can make sure that the connections will not interfere or meddle with the OBD computer and its power and connection supply.

Contact your dealer or your car’s service center.

If you still can’t find the issue regarding the OBD2 port, you may want to contact your car dealer or your unit’s service center for assistance.

This way, you will have mechanics and technicians to properly diagnose your car if ever the OBD2 systems won’t work. Also, they have a sort of analysis through their OBD generic tool. Finally, they will likely connect the DLC or the data link connector and do other steps to fix that non-communication issue.

Check the OBD computer.

Examine any emission monitoring system and OBD computer tech support advisories and service plans. Use your vehicle identification number to notify your dealership or service center and have their staff look into the following.


In a nutshell, the OBD2 plays an important role when diagnosing problems in your car. Thus, it can be quite troublesome when it stops communicating. In general, the best way to have your OBD2 problem fixed is to take it to a technician. However, if you know you’re way around checking the possible causes of this issue, you can save a lot of money, time, and effort.

The steps mentioned above should help you fix the issue if ever it happens to you. If it persists despite your efforts, you’ll want to take it to a service center since it can be a more complicated problem.

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Image credits – Canva

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My name is Hank, and I've been in the automotive industry for 27 years. I've been working in my own auto repair shop for the last 13 years, and now I want to help you here, on my blog. Let me know if you have any questions. Read more