CarMD OBD-II Scan Tool Review

No one likes to start their car up in the morning and see their check engine light stay on. It stares at you – heck even your eyes are drawn towards it. At night it’s almost blinding. When you take your car in for service, no one wants to pay artificially inflated bills. Knowing what is wrong before you even show up is a good way to save money.

A new company CarMD has an easy and quick tool that will ease your check engine light woes. This scan and diagnostic tool uses the OBD-II port on your 1996-and-later car to check for trouble codes and helps you identify what is wrong.

The CarMD scanner has been sitting on our shelf for a little while now just waiting for a check engine like. Then, low and behold, I become the problem child. One day on my drive into work there is now bright orange lettering that says “Service Engine Soon” on my 2007 daily driver. People usually associate check engine lights with old cars, that’s just not the case.

It seems that modern day cars have more sensors then the Space Shuttle. With more sensors can come more problems. The scanner is priced cheaper then what a one time diagnosis charge would cost you at a typical shop. Even though my ride has 35,000 miles on it, and is still under warranty, I still want to know what is wrong with my car and the CarMD scanner was about to tell me.

I opened up the box, and here’s what I found.

  1. The CarMD hand held tester that links to your vehicle’s computer automatically
  2. Access to, an online database that gives you reports on what your check engine light means and estimated repair cost.
  3. User Guide
  4. Demo Video
  5. Software on a CD
  6. USB cable to link the CarMD tester to a Windows-based PC

What does OBD mean?

For those who don’t understand what OBD means, here is the low down:

OBD stands for On-Board Diagnostics. OBD started in in the late eighties and then evolved into OBD-II in 1996. OBD 1 was designed purely to encourage auto manufactures to design reliable emission control systems. This was a huge failure as the emission reporting was not standardized. OBD 1.5 was a cross over to OBD-II that occurred during 1994-1995. Most vehicles in the transition came with an after catalytic converter oxygen sensor. The main function of this sensor was to make sure the catalytic converter was there and functioning properly. Additional revisions was the partial OBD-II code implemented into the OBD-I ECUs.

The big OBD-II change consists of a universal diagnostic connector, electrical signaling protocols, and the messaging format. This means that the car can query outputs from multiple sensors and log them onto the ECU. This becomes your most valuable tool for data logging and trouble shooting.

The CarMD is compatible with OBD-II and any vehicle made 1996 or later.

How do Check Engine Lights Work?

All current year vehicles are required to have a check engine light or a “MIL” – Malfunction Indicator Light. The light shows three different types of signals:

• Occasional flashes show momentary malfunctions.
• The light stays on if the problem is more serious, especially if it affects the emission control system.
• A constantly flashing light is a sign of a major problem that can cause a serious problem to your engine.

Another way of knowing that you car has a serious check engine light is simply the car’s drivability. If the check engine light is on and the car is performance remains unscathed, then the trouble code is more then like not as critical. Sometimes you will get the feeling that your car is running on a few less cylinders. This is generally a sign of something more serious as now the car is running in “Safe Mode”. Safe Mode is triggered when the ECU thinks your car is having a heart attack. It will run air fuel ratios really rich and pull tons of timing to help prevent any sort of detonation due to a malfunctioning sensor. These critical sensors can include air intake temperature, oxygen, and fuel management sensors.

Getting those Codes

There is no special guess work when it comes to pulling codes off your ECU. Most OBD-II codes are generic but some manufactures do carry some personalized codes. This means that one CarMD scanner can work for any type of car that has an OBD-II ECU. The brain in your car saves the code and the scanner simply sends it as a typical P or PH based OBD code that relays to the display.

The CarMD scanner is very easy to use. It plugs right into your OBD-II port that’s usually located under the dash or at least within reach of the drivers seat.

After it beeps twice, turn your key all the way over so your dash lights and stereo turns on.

Shortly after the CarMD will beep four times to indicate that the scan is complete. Turn the ignition off and pull the scanner out of the OBD-II port. The scanner will show a P followed by numbers (in my case, P2000). The online CarMD application will decipher this jibber-jabber for you.

Next you will need a PC that connects to the internet. Install the programs on the supplied CD. The CarMD software comes with a good “How to work this thing” video on the disc itself. After the program is installed, hook up the CarMD scanner into an available USB port on your computer. The scanner will launch a web page that will prompt you to enter some information about yourself. Finally it will forward to a screen that shows your problem and probable cost to repair. Since my car is too new, there was no cost estimate for my problem. In that case there is a button that will send the request to a CarMD tech that will reply a customized report to me.

Within fifteen minutes, I went from having the scanner plugged into my car to receiving my problem report on CarMD’s website. Even though I am mechanically inclined, the scanner is easily operated by the most un-savvy soccer moms. Now when I take my car to the dealer I know exactly what work needs to be done so there aren’t any hidden issues or fees. Overall, the CarMD is a good little tool for your tool box, and especially good for an auto-notive.

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About the author

Mark Gearhart

In 1995 Mark started photographing drag races at his once local track, Bradenton Motorsports Park. He became hooked and shot virtually every series at the track until 2007 until he moved to California and began working as a writer for Power Automedia. He was the founding editor for its first online magazines, and transitioned into the role of editorial director role in 2014. Retiring from the company in 2016, Mark continues to expand his career as a car builder, automotive enthusiast, and freelance journalist to provide featured content and technical expertise.
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