Obd2 Port Not Working?

Obd2 Port Not Working? Check the Reasons

When the check engine light comes on your car, it’s a sign that your vehicle’s system is having issues. Therefore, the noble thing to do is park your car and find out the problem. If you have a diagnostic scanner, you can check the problem by yourself. But if you don’t have one, you may have to visit the mechanic.

However, some people find it difficult to comprehend the problem when the OBD II port of their car isn’t working. If this happens to your precious vehicle, you don’t have to panic but detect why the OBD2 port isn’t working.

Check the Reasons Why Your Obd2 Port Not Working

We’re going to discuss the reasons why your OBDii port is not working and how to fix it. So, read to the end to find out.

A bad ground

One of the main things that can make your OBD port fail to work is bad ground. It usually prevents communication between the computer and the OBD2 scanner. Pin 5 is the ground. To know whether a bad ground hinders your OBD port from functioning correctly, locate the OBD2 port and test it to see if the ground is good.

You can test the ground by keying off and utilizing a 10 megaohm impedance ohmmeter to test the pin 5 to the ground. However, if the ground is working fine, you should check whether there’s a broken circuit.

Broken circuit

A broken circuit can also block communication between your vehicle’s computer and the diagnostic scanner. The circuit usually breaks between Pin 2 back to the PCM, or the PCM may be bad. If the PCM is bad, many functions of the car will be disrupted with the inclusion of the OBDII Port. This is because the module won’t be able to read sensors correctly.

Related article: Easy steps to test O2 sensor with an OBD2 scanner

Additionally, there may be a broken circuit between the OBD2 connector and ECU or a bad ECU. Like the PCM, a bad ECU will also not operate the car properly, which will affect the functioning of several parts of the vehicle like the OBD 2 port.

Broken connection

If one of the 16 pins in the OBD2 port is pushed back or bent, it won’t make the needed contact with your scan tool plug. As a result, the OBD ii port won’t work unless connected to the correct pins. However, if all the pins are working fine and there is good continuity, then the ECU may be bad. In that case, it will not show the OBD2 diagnosis symbols.

A blown fuse

Another reason why your advanced OBD2 scanner may not work is because of a failed fuse. So check the fuse box as If the fuse box blows, the OBD port won’t work. Most vehicles blow fuses because of their lighters. Therefore, if you want to know if the OBD 2 port is not working because of a blown a fuse, you should start testing your cigarette lighter.

The cigarette lighter and fuse box usually are on the same circuit. Hence, if the cigarette lighter or accessory port spoils, it may also affect the functioning of the fuse as there will be no power going to the PCM and ECU.

Rust on pins or clogged port

You won’t get any connection to a scanning device if there is no power at pin 16. If none of the above reasons have been detected to make the OBD II port not work, you should examine the pins and port. For example, the pins in the port may have rust after many years of use. On the contrary, a clogged port can also be why connecting between the ECU and OBD scanner is not possible.

Related article: How can you clear OBD2 codes without a scanner?

The best solution is to clean the port and get rid of dirt, dust, and debris inside the port. Then, utilize the correct cleaners and tools to eliminate rust and dust in the vehicle’s OBD2 port.


With the above information, you should never panic if your OBDii port isn’t working. But before assuming that your port is bad, you should ensure that the scanner is compatible. As stated above, various things can make your OBD port fail to work. These include a broken circuit, bad ground, broken connection, blown fuse, rust, and clogged port. You can use a Bluetooth OBD2 scanner, including Bluedriver or Innova 3140g scanner, to avoid this issue.

If you don’t have the tools to examine your OBD 2 port, contact a professional mechanic to help you out. Also, always plug in your OBD cable carefully to avoid damaging the pins in the port. You can now go ahead and repair your port so that you can tell why the check engine light is on.

Still, have questions after reading this “Obd2 Port Not Working” article? Comment below.

Scroll to Top