How to Read OBD Codes

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We’ve all been there. You’re driving along minding your own business and you notice it. Your check engine light is on! How is this possible? How could this happen?

Don’t panic. Your CEL (check engine light) coming on isn’t the end of the world. In fact, it might not even be a serious problem that needs fixing.

As long as you have an OBDII scanner to check and see what the problem is, you don’t have anything to worry about yet.

A little Background on OBD 2 Scanners

You probably already know what an OBD 2 code reader is, or at least that you need one to check why your CEL is on. To put it simply, an OBD 2 scanner is a device that connects to your vehicle’s OBD port and gets readings from your vehicle’s OBD 2 system.

However, not all vehicle’s have an OBD system, so keep this in mind. If you have an older vehicle that wasn’t manufactured in the past few decades, it could be possible that it’s actually too old to even have an OBD system yet.

OBD systems came about in the early 80s, so if you have a model that’s that old or before that, you might be out of luck.

If your car is new enough for OBD 2 (2003 onward), that’s the best of all!

Should You Buy Your OBD Code Reader or Rent One?

Considering how affordable prices are for OBD scanners these days, there’s no reason not to get your own.

The cost of renting one a couple of times is roughly equal to having your own, especially when you factor in the extra time and gas you need to invest to go to the auto parts store back and forth. Renting really doesn’t make sense.

You can buy a great OBD code reader online and have it shipped to your address.

How to Use an OBD Code Reader for Your Automobile

First, in order to use an OBD 2 code reader, you need to have one! Once you’ve selected the right one for your needs, bring it over to your car and find the OBD scanner port. It’s typically situated beneath the driver’s side dashboard. It will look like a plug with 16 tiny connectors in it.

Plug the adapter cable that’s connected to your handheld OBD device into your car’s OBD port. It should fit in easily. If not, it may take a little bit of wiggling back and forth for it to fit into place.

If the adapter is properly connected, the OBD code reader should automatically switch on and display its home menu. Then, you can select the option that you’d like to use, such as “begin diagnostic”.

The scan will show any DTCs (diagnostic trouble codes) that it detects, and will identify them as either pending codes (issues that aren’t super serious yet), or stored codes (issues that are bad enough to trigger the check engine light).

Once you have the codes (if any show up), you can look up what they mean, either through the device itself if it has support for that, or by Googling their meaning.

What to Do if Your OBD 2 Scanner Won’t Connect

If the adapter is not properly connected, or if the car you're attempting to connect the OBD scanner to is not compatible, your OBD scanner device will say something like "connection error.”

If this happens, you should disconnect the OBD 2 scanner and then reconnect it. If the same problem happens again, then your OBD 2 scanner is probably not compatible with your type of vehicle. It could be that or maybe your car is too old, or if not that, then there may be a bad connection with the adapter cable being damaged or faulty.

Using a Universal OBD 2 Scanner Can Prevent Compatibility Issues

If your aim is to have an OBD scanner that you can use on more than one vehicle, it’s probably best to go with a universal model that allows for compatibility with many different makes and models from manufacturers from all over the world.

However, that’s not to say that any “universal” OBDII code reader will work with absolutely every type of vehicle that has an OBD system. Most universal code readers cover a wide range of different brands but aren’t totally comprehensive.
When you purchase your OBD code reader, check which manufacturers or regions it’s compatible with. The maker of the OBD code reader’s website may simply list out which countries its device supports. Just make sure that the manufacturers of the cars you intend to use the device for are from the regions it supports.

What’s the Best Universal OBDII Code Reader?

There are many good options out there on the market, but you don’t want to break the bank just to end up with a low-grade device. Unless you work in a car garage and need the absolute best model you can get your hands on, you should opt for a good quality mid-range device. This will provide all of the functionality you need for at-home use and then some.

We recommend the Ancel AD530 OBDII code reader. This device is very robust, and has additional features that put it above your average OBDII scanner.

However, it still has an affordable price tag, especially compared to other models that perform similar functions.

It includes definitions for all DTCs, a large color display, and a wide range of features that let you monitor your vehicle’s health very closely. It’s one of the best options on the market in its price range.


It’s a good idea to run diagnostics on your car on a regular basis. That way, you can keep an eye out for any pending codes and solve them before they grow into bigger and more expensive problems.

Buy an OBD2 code scanner online and keep it in the trunk of your car so that if the check engine light ever comes on, you’ll be able to handle it right then and there.

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