OBD Scan Tools

A warning light just lit on your dash.  What do you do…take it to the dealership right away, or try to figure it out yourself?  Today’s cars are complicated, so it helps to have the right tool to identify issues before spending time and money on repairs.

One of the best tool purchases you can make is a scan tool. Scan tools come in several flavors, from simple code readers to complex diagnostic tablets.  What are they and what do they do? 

Let’s take a moment to talk about vehicle diagnostics, then look at the range of diagnostic scan tools.

On-board Diagnostics (OBD) 

OBD is a term referring to a vehicle’s self-diagnostic and reporting capability. In the United States, this capability is a requirement to comply with federal emissions standards. It detects failures that may increase the vehicle tailpipe emissions. 

OBD systems give you or a repair technician access to the status of the various vehicle subsystems.  In the early 1980s, a Check Engine warning light would illuminate.  In 1996, a universal OBD II system was mandated on all US vehicles with gas engines and gross vehicle weight ratings under 8,500 pounds. This manadate also requires a standardized diagnostic port under your dash, which allows you to plug in your scan tool to run diagnostics.

Scan Tools

What do you do if one of the above icons lights up on your dash?  For starters, don’t panic.  It’s very likely your car’s computer detected something that affects the tailpipe emissions.  It could also mean a fault with the antilock brake system, or a number of others.  Some severe, some not.

In order to determine the severity of the problem, you must find out why that light is lit.  This is where a scan tool is needed.  Regardless of the tool, it will plug in to the diagnostic port under your dash.  Picking the right tool depends on your level of experience (or comfort) working on cars:

Code Reader

This is a simple plug-in device that does one thing–read which fault codes are active in your vehicle’s system.  Once you identify the code, you can Google it to see what it is and how to address it.  

One of the most frequent codes you will experience is either P0456 or P0457, which indicate a leak in the evaporative emissions system.  What is the likely cause?  A loose gas cap, which usually happens right after you fuel your car and don’t tighten the cap.  In this case, tighten the cap and use the “erase code” feature to turn off your check engine light.

Code readers can be purchased for under $30 at most auto parts stores (these typically only read the engine emissions codes).  I bought one at Amazon for my son for $15 (he lives in Atlanta, so he will plug it into his Jeep, then give me a call to discuss his issues).  Very handy for less experienced users.  

Bi-Directional Scan Tool With Tablet

Repair shops use a very sophisticated scan tool that can go deep into vehicle subsystems to detail diagnostic work.  Those scan tools are loaded on a durable tablet with a large display.  In addition to reading codes, various sensors and electronic parts can be activated by the tablet.  More importantly, recommended fixes are available in the program.

As you might expect, these scan tools can get expensive–costing thousands of dollars.  One of the repair channels I watch on YouTube recommends the King Bolen scanner for under $500.  That’s still a lot of money for a DIYer, but sometimes it’s nice to have the big toys!

Happy Medium:  Bluetooth Scan Tool

In addition to my own cars, I have friends and family members who seek my help with theirs.  This not only gives me an excuse to buy something more than a code reader, but also offers me more capability when diagnosing issues.

Through my travels, I discovered several bluetooth scan tools that have most of the capability of those expensive ones, but at a fraction of the cost.  These bluetooth scanners have a dongle that plugs into the OBD diagnostic port, but uses an app on your phone to run the tool.  

I saw a nice testimonial for the TOPDON TopScan Lite, so picked one up last week. It is normally $90, but I was able to buy it for $56 on sale.  One of the biggest pluses for me is the ability to reset the maintenance reminders (oil change interval, etc.) and register a new battery (BMWs and MINIs require this operation whenever a new battery is installed).  Battery registration/resets will cost $100-200 at a local shop.  This tool paid for itself on the first use!

The BlueDriver Bluetooth Pro is also supposed to be a good tool.  I don’t have any direct experience with it, but it’s been around a while. At around $100, it is also more expensive than the TOPDON.

Final Thoughts

Not everyone is comfortable working on a car, but being an informed consumer is important.  It can help you determine the severity of your vehicle’s problem.  If you are handy around cars, it can help you with vehicle repairs.  

My recommendations above come from other pros in the business.  I provided links to each one through Amazon, but they can be purchased elsewhere.

Please share any thoughts or questions in the comments below.