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CarMD Frequently Asked Questions … And Responses

This list should provide you answers to the most common questions about CarMD. If you do not see a response to your question, please contact our customer support team.

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CarMD product questions

Q: What is CarMD?
A: The CarMD® Vehicle Health System™ is a consumer product designed to provide the average driver with the tools and information to monitor your vehicle’s health, catch hidden problems and diagnose dashboard warning lights. While it uses professional quality tools and information, it’s simple enough for anyone to use to find out what’s wrong with your vehicle and what repairs will cost in your geographic area. The CarMD handheld device is ready to use right out of the box, and includes everything needed to monitor a car’s health – an easy-to-use handheld device, Mac/PC software, USB cable, two AAA batteries, handy caddy, and lifetime software and firmware updates.
Q: Who can benefit from owning CarMD?
A: Anyone who owns or is responsible for the upkeep and maintenance of a 1996 (U.S.) or 1998 (Canada) or newer vehicle can benefit from CarMD®. It is designed to work on newer model vehicles driven in the North America, with on-board diagnostic technology. This includes cars, light trucks, minivans, SUVs and hybrids – foreign and domestic. All vehicles sold in the U.S. since 1996 and Canada since 1998 are required by the government to have an on-board computer and this technology. Many drivers don’t realize their cars have this connector. To make sure your vehicle has this technology, you can look under the hood for a sticker that says “OBDII” or “OBD2.”  Click here for further information.
Q: What do I do if my vehicle’s model is 1995 or earlier?
A: Many vehicles manufactured in the ‘80s and early ‘90s use OBD1 technology, the predecessor to today’s second-generation diagnostics program (OBD2). This first generation OBD system monitors manufacturer-specific systems, but is not universal like OBD2. Some 1994 and 1995 vehicles use OBD1 while others have OBD2 systems. If your vehicle happens to have an early OBD2 system; the CarMD tester may plug in but there will not be sufficient information in the CarMD database to tell you what’s wrong.
Q: Where does CarMD plug in? I don’t want to have to look under the hood.
A: You’re in luck. You don’t have to pop the hood or risk getting greasy to use CarMD. It can be used from the safety and comfort of your vehicle’s front seat. There are nine different locations inside the car where the OBD Data Link Connector can be found. The most popular location is just under the steering wheel. Click Here to find where it is on your vehicle.
Q: What if I’m not comfortable doing car maintenance?
A: CarMD is very easy to use right out of the box. You do not need any automotive experience, and you don’t have to lift the hood or get dirty to use it. The CarMD handheld device plugs into a port found right in the comfort and safety of each vehicle’s front seat. If you’re not sure where it is on your vehicle, you can visit the CarMD website to search by year, make and model, and even see a photo of where it is on your car.
Q: Are there parts of the vehicle that CarMD does not monitor?
A: The CarMD tester monitors all of the systems throughout the vehicle that are related to on-board diagnostics and its emissions output. This translates into coverage of approximately 80 percent of the vehicle’s systems. Some of the parts of the vehicle that are not monitored by OBD2 include: tires / tire pressure, ABS, airbags and sound system. The CarMD tool and website are meant to provide a basic overview of probable causes related to electronic and emissions related systems in your vehicle. This product should be used as a supplement to a regular automotive maintenance program, which also includes basic mechanical upkeep such as regularly checking your tire pressure, oil and fluids, etc.
Q: How does the CarMD handheld device compare with the tool my mechanic uses?
A: Most professional automotive technicians use scan tools that can cost several thousand dollars. These scan tools can only be used by technicians who are trained to read the often complicated diagnostic data. The CarMD Vehicle Diagnostic Device uses similar diagnostic technology, but costs significantly less and displays information that can be read and understood by anyone – no training necessary. It is meant to guide you as part of an overall vehicle maintenance program, and to help you better understand what’s wrong with your vehicle. It should not completely replace regular maintenance and repairs performed by a qualified technician.
Q: Where does CarMD get its information from?
A: The CarMD database has been under development since 1997. Solutions come from CarMD’s network technicians across North America who input and validate fixes daily. CarMD goes beyond simply defining diagnostic trouble codes by using year, make, model, engine and transmission type, mileage and zip code to statistically assess and diagnose the most probable fix for each vehicle’s problem. This database is helping consumers and professional technicians alike to solve tough “check engine” problems. When CarMD presents a most likely fix for a vehicle, its database is sifting through more than a half-million real-life fixes made by skilled mechanics who work on cars just like yours every day.
Q: How is CarMD different from a free scan at my local auto parts store?
A: When you get a “free” scan at the local auto parts store they will most likely hook up an on-board diagnostic (OBD) code reader or scan tool to your vehicle. Depending on which brand of tool they use, they’ll either give you a diagnostic trouble code (DTC) or a DTC with generic definition that reads something like “MAF Sensor Signal Range” or “Transmission Control System Electrical.” This will give you a very basic understanding of what might be wrong with your car, but won’t tell you what parts are required to fix the problem. The counter staff may also use a booklet or conduct an online search to recommend parts. While the CarMD handheld device is similar to the scanners used by parts stores, the complete CarMD system goes beyond the capabilities of a “code reader.” CarMD is the only consumer automotive diagnostic system that is backed by the largest database for OBD2-related problems. In addition to getting a patented, award-winning handheld diagnostic tool, CarMD customers gain access to the largest repair database dedicated to check engine-related problems. Instead of getting a best guess on needed parts, with CarMD you get a statistical consensus from thousands of practicing automotive techs on the most viable fix for your vehicle’s problem. And if there is more than one fix possible, you see the other possibilities.
Q: Does CarMD work on RVs?
A: Please be aware that CarMD is designed to work on cars, light trucks, SUVs and minivans. The tool does read diagnostic trouble codes for some Class A RVs, but it is not designed for this application.
Q: Does CarMD work on motorcycles?
A: No. CarMD is not designed to work on motorcycles.
Q: How Can I use the CarMD handheld tester by itself?
A: The CarMD tool itself can be used on an unlimited amount of vehicles to get a clean bill of health, provided the vehicle in test is a 1996 or newer car, light truck, SUV or minivan. The handheld tester features patented, color-coded LEDs to let you quick check any vehicle. Just plug in the tool to get the peace of mind that a green LED can give you. Here are some of the many things that the CarMD tester can confirm without needing to proceed to your PC:
  • Give your vehicle a clean bill of health before you hit the road for a long trip
  • Determine if a vehicle is ready to pass an emissions test
  • Check out a used car before buying
  • Confirm repairs were successful
  • As part of a monthly maintenance program
  • Quick check vehicles owned by friends, family, neighbors and co-workers 
Q: Can CarMD help me prepare for a state emissions test?
A: Yes. Now that OBD2 vehicle population is rising, many U.S. states and Canadian provinces are using OBD2 testing in place of the traditional tailpipe testing to pass or fail vehicle emissions or “smog” checks. While requirements vary slightly from state to state, CarMD reports can help ensure if you are ready to pass your emissions test. Click Here to learn more about it.
Q: This tool is so affordable. Can it really do what you say it can?
A: Most definitely. CarMD is made and distributed by an automotive aftermarket manufacturer with nearly 40 years of experience making automotive test equipment. Our years of expertise and sheer product volume enable us to make this revolutionary tool and information available to you – at a very affordable price.
Q: Do I need to purchase another CarMD tester if I buy or sell my vehicle?
A: No.The CarMD technology is guaranteed to work on all vehicles with OBD2 technology. If you buy or sell a vehicle, you can contact the CarMD customer service department to add or disable this vehicle from your account once per year at no extra charge.
Q: Are CarMD customers required to purchase a subscription fee or software updates?
A: No. The purchase of your CarMD tester includes lifetime vehicle coverage for up to three (3) vehicles at a time and software/firmware updates at no additional cost. There is an option to purchase TSBs (Technical Service Bulletins) a la carte or with a CarMD® Premium Vehicle Health Plan™, but this is not required for use of the product.
Q: Money’s tight these days. Do I have to purchase a subscription to use my CarMD product?
A: Absolutely not. Everything you need to diagnose your registered vehicles is included with the price of your CarMD purchase, including FREE lifetime software and firmware updates. CarMD simply offers the option to purchase a Premium Vehicle Health Plan Membership, which gives you value-added information to monitor your vehicles’ health, including warranty & scheduled service information and access to see all of the technical service bulletins for your cars. This can often result in low- or no-cost repairs, and is a great value if you have more than 10 known TSBs for any one of your vehicles.
Q: Can I sell my CarMD product and are there any transfer of ownership fees?
A: CarMD currently charges a $25.00 fee to transfer ownership of the CarMD device. This policy has been put in place to protect our customers from theft and prevent abuse of product usage. It also helps compensate for the customer support and programming time associated with changing the customer registration and password information.


Check Engine Light questions

Q: What does it mean when my "CHECK ENGINE" light comes on?
A: The "CHECK ENGINE" light comes on when your vehicle’s On-Board Diagnostics computer finds a problem that may affect emissions. Problems can range in severity from a loose gas cap, which wastes fuel and causes pollution, to an engine misfire, which may cause permanent damage. In any case, there is no need to panic. Most of the time, it’s just the vehicle’s computer telling you to get it looked at soon. Always reference your vehicle’s service manual for what to do when your “CHECK ENGINE” light comes on.
Q: What is On-Board Diagnostics (OBD)?
A: On-Board Diagnostics are part of the U.S government’s mandate to help automotive manufacturers lower vehicle emissions. It’s a universal program installed in a vehicle’s computer system that is designed to detect malfunctions, set a diagnostic trouble code (DTC) and turn on the “CHECK ENGINE” light if there is a problem. All 1996 or newer cars, light trucks, SUVs and minivans manufactured for use in the U.S have the most advanced OBD, called the second-generation on-board diagnostics program (OBD2).
Q: Can a loose gas cap cause my “CHECK ENGINE” light to come on?
A: Yes. Loose gas caps are one of the most common reasons the “CHECK ENGINE” light comes on. If CarMD tells you a loose gas cap is the culprit, tighten it until you hear it “click.” Then be patient. It may take a few trips around the block, or even a few separate starts, before the “CHECK ENGINE” light re-sets. If the cap remains loose, replace it. Make sure you use the correct cap for your specific make and model.
Q: Can I use CarMD to turn off my “CHECK ENGINE”, ABS or SRS lights?
A: No. It is not recommended for drivers to turn off their vehicle’s “check engine” or other dashboard lights until the pending or current problem has been identified and repairs confirmed. Doing so erases valuable information that may be needed to repair the vehicle, including driving conditions when the light came on. Once the correct repair is made, your vehicle will run its tests and often turn off the “check engine” light on its own. This may take longer than when a mechanic does it, but that is a safety feature that CarMD has purposely included to protect you and your vehicle.
Q: What about when my “CHECK ENGINE” light is blinking?
A: A blinking or flashing dashboard light usually indicates a more severe problem. When this occurs, it’s best to limit your driving, check your vehicle service manual and schedule an appointment to have the problem looked at by a professional technician as soon as possible.
Q: There’s a light on in my car that says “Service / Maintenance Required.” Will CarMD tell me why it’s on?
A: No. The “Service / Maintenance Required” light comes on when it’s time for your vehicle’s regularly scheduled maintenance. This light is scheduled by the manufacturer to come on after a certain amount of miles. Use CarMD to check for possible problems before your scheduled maintenance and as a way to double-check what your mechanic is telling you when you take your car in.


Buying/Selling a vehicle questions

Q: How can I use CarMD to shop for used cars?
A: The CarMD handheld device can be used to “quick check” an unlimited number of vehicles. As long as the seller gives you access to the keys, you should quickly and easily be able to run a CarMD scan on any 1996 and newer vehicle you’re considering. It’s much quicker than taking the time to arrange to drive it to your mechanic, and the CarMD handheld device can quickly give you an indication as to the vehicle’s engine health along with possible hidden problems. Just plug the CarMD into the vehicle, turn the ignition to the “on” position and wait for CarMD to do the rest. Once it beeps, you can unplug the CarMD tester and read the color-coded LEDs. Green indicates there are not currently any problems with that vehicle’s engine and emissions systems. Yellow indicates a possible problem that could just be a simple warning or could signify repairs will soon be needed, and red indicates a current problem that can range in severity from a loose gas cap to major engine damage. CarMD is not meant to replace a full inspection of the used vehicle, but it’s a great way to get a second opinion without a lot of hassle.
Q: What if the seller doesn’t want me to use CarMD on the vehicle?
A: CarMD takes just a few seconds to use and won’t cause any damage to the vehicle it’s connected to. It’s actually much easier to run a scan with the CarMD device than it is to arrange to drive it to your mechanic for a second opinion. If you explain this to the seller and he or she is still not comfortable with your using CarMD to check the vehicle’s health, they may be hiding something from you, and you may wish to shop elsewhere for your next vehicle purchase.
Q: Can I get a diagnostic report for the used car I’m interested in?
A: Yes. As long as the seller provides you with the keys to run a scan with your CarMD handheld device and you can get the vehicle identification number (VIN), you can run a CarMD report for that vehicle. Since a red light report will count toward your allotted registered vehicles and monthly reports, CarMD recommends that you reserve running a complete report for the vehicle you’re most interested in purchasing. If you can’t get to a computer while you’re shopping for that used car, you can jot down the VIN and run a report when you get home (CarMD will store the code in its memory until you remove the batteries or connect it to a different vehicle). Or, you can call toll free 888.MyCarMD to get a diagnosis from the lot.
Q: I’ve heard about used car dealers cutting the “CHECK ENGINE” light wire or poking a hole in the bulb. Will CarMD work if the wire has been cut or the bulb is out?
A: Yes. We’ve all heard stories about used car fraud. Fortunately, a vehicle’s computer stores codes even if the “CHECK ENGINE” light wiring has been disconnected or the bulb is out. CarMD will access these codes and display a red LED indicator if any are present. Also, if the seller has recently cleared the computer’s memory, the CarMD tool will indicate a possible problem with a yellow LED. If you don’t have a CarMD handheld device, the best way to confirm the “check engine” and other dashboard warning lights are in good working order is to put the key in the ignition and turn it to the “on” position. As soon as you start the car, all of the warning lights should flash to tell you they are in good working order and then turn off when you start to drive, unless they’re signaling a problem.
Q: If I get a green light on the CarMD device, does that mean I should buy the car?
A: A green LED on the CarMD handheld device indicates that the vehicle does not currently have any OBD2-related problems. That means there is not currently any problems with the engine, transmission, emissions-related systems and essentially about 80% of the vehicle’s systems and sensors. A green light is a very good indication that the used car is in good condition. However, you should never purchase a vehicle based solely on a CarMD diagnosis. You should also conduct a thorough visual inspection of the vehicle looking for body damage, worn tires and general wear and tear. You should also ask to see the vehicle’s service records, determine if it’s in good overall condition and ensure the asking price is fair.
Q: If I get a yellow light on the CarMD device, what does that tell me as a used car shopper?
A: A yellow LED on the CarMD handheld device tells you to proceed with caution and ask the seller a lot of questions. A yellow light can mean one of a couple things. First, it could indicate that the car’s computer saw something it didn’t like, but it hasn’t yet triggered the “check engine” light to come on. Repairs could be required in the near future. But a yellow light can also mean the vehicle was recently serviced and it hasn’t been driven enough to confirm the repairs have been properly made. If you get a yellow light on the CarMD device, it’s a great reminder to ask the seller lots of questions about the vehicle, including when it was last serviced. If you remain interested in the vehicle, running a complete CarMD diagnostic report can tell you more about what’s wrong and how serious it may be.
Q: If I get a red light on the CarMD device, does that mean it’s not a good used car to purchase?
A: A red LED on the CarMD device tells you the vehicle currently has a problem, but that problem can be anything from a loose gas cap to complete engine failure. If you’re really interested in the vehicle, don’t let a red light on the CarMD device keep you from buying. It’s a good idea to run a complete CarMD diagnostic report to determine the cause and most likely fix. By knowing what’s wrong you won’t pass up a good deal because of a loose gas cap, and you won’t get stuck with a lemon that needs major work a few miles down the road.
Q: Do I need to purchase another CarMD tester if I buy or sell my vehicle?
A: No. The CarMD technology is guaranteed to work on all vehicles with OBD2 technology. If you buy or sell a vehicle, you can contact the CarMD customer service department to add or disable this vehicle from your account once per year at no extra charge.


Pro(mechanics/technicians) questions for CarMD

Q: Who can benefit from using the CarMD Vehicle Health System product?
A: Anyone who drives a 1996 or newer vehicle (U.S.) or 1998 and newer vehicle (Canada) can benefit from CarMD. It’s designed to work on vehicles with on-board diagnostic technology. This includes cars, trucks, minivans and SUVs – foreign and domestic. It also includes newer hybrid vehicle and heavy-duty trucks model 2010 and newer. While CarMD is designed mainly for consumer use, skilled do-it-yourselfers will appreciate its ease of use, accuracy and price, and can help friends and family by offering to run an unlimited number of “quick checks” to see if their friends and family’s vehicles have any hidden problems (note: there are some usage limitation for running detailed diagnostic reports, but you can plug the handheld device into an unlimited number of vehicles for a quick health check). Further, professional technicians will appreciate that CarMD was developed by a highly skilled team of Automotive Service Excellence (ASE)-certified technicians, as well as the fact that an informed customer is much easier to communicate with.
Q: How does the CarMD tool compare with a professional scan tool?
A: CarMD uses the same basic on-board diagnostic, second generation (OBD2) technology found in more expensive scan tools. CarMD is able to diagnose about 80% of the OBD2-related problems on vehicles, particularly those that do not require live data or graphing to diagnose. We realize that trained mechanics use scan tools that often cost thousands of dollars and can only be used by technicians who are trained to read the complicated diagnostic data. CarMD is not meant to replace these “big box” tools. Rather, it’s designed to provide basic, yet highly accurate, repair information to consumers at an affordable price so they can understand what’s wrong with their vehicle with no training necessary. That way the car owner can make an informed decision about when, where and how to schedule repairs, and even budget accordingly before they schedule repairs
Q: Why do you limit usage and number of reports? Without these limitations I could use it for my repair shop.
A: CarMD is a consumer tool designed to meet the needs of the average household. Our consumer customers can use CarMD to quick check an unlimited number of vehicles. They only need to register and run reports for a vehicle if they have a yellow or red LED. We limit it to registering three vehicles and running six reports per month because our data is so valuable. If we didn’t, we could potentially have every mechanic in North America using our data to help solve problems at little to no cost.
Q: Do you have a professional version of CarMD?
A: At this time, CarMD does not have a professional version of our product. We are looking into the possibility of designing products and services to benefit professional automotive technicians. For updates, we encourage you to check our website regularly or follow us on Linked In.
Q: Can CarMD be used to turn off the check engine light and clear diagnostic trouble codes?
A: No. Since CarMD is designed mainly for consumer use, we deliberately opted not to include a function to clear trouble codes. We always caution our customers that it is not recommended for drivers to turn off their vehicle’s “check engine” light until the pending or current problem has been identified and repairs confirmed. We explain that doing so erases valuable information that may be needed to repair the vehicle, including driving conditions when the light came on. We remind our customers that once repairs have been made by the consumer or their trusted mechanic, the vehicle will run its tests and often turn off the “check engine” light on its own. And we further explain that this will take longer than when a mechanic does it, but that is a safety feature that CarMD has purposely included to protect our customers.
Q: I’m not comfortable doing repairs based solely on the CarMD report. How do I explain to my customer that I need to run a diagnostic before I can make repairs?
A: While we are confident in the accuracy of CarMD’s diagnostic reports, we completely understand that a repair technician needs to conduct his own assessment before agreeing to make repairs. It would be similar to a female customer taking a home pregnancy test and expecting her obstetrician to take her word for it. We also understand that during the time after the report was generated, it’s possible the vehicle’s condition has changed. Our diagnostic reports state, “This information is designed to guide and empower you in your automotive repair and maintenance decisions. Always consult with a qualified automotive technician before making repairs.”
Q: I replaced the part associated with the code found on my CarMD tool, but the same code recurs.
A: The CarMD handheld tester is designed to retrieve Diagnostic Trouble Codes (DTCs) from your vehicle’s computer. The code(s) shown on the tool serve as a starting point for repairs. You should never replace a part based only on the DTC definition. To further decode the most likely fix associated with the code or codes pulled by the tool, you should connect the CarMD handheld device and generate a MyCarMD report, which provides most likely fix along with do-it-yourself and repair shop costs. If you are a professional automotive technician or seasoned do-it-yourselfer, we recommend you closely review the diagnostic trouble report. Each code will lead you to a system or circuit on the vehicle that will require further testing to isolate the cause of the code. Each DTC has a specific set of testing procedures and instructions that must be followed to confirm the location of the problem. To accomplish this testing, additional tools as well as a good service manual are required. It is important to remember that if you are an average driver with little or no automotive repair experience, this information is designed to guide and empower you in your automotive repair and maintenance decisions. Always consult with a qualified automotive technician before making repairs.


CarMD technical questions

Q: I noticed that CarMD customers can register and run up to six (6) monthly online reports for up to three (3) registered vehicles. What if I need or want more coverage?
A: CarMD is a consumer tool designed to meet the needs of the average household. You only need to proceed to the online report generation / vehicle registration if you get a yellow or red light on the CarMD handheld device. Additionally, if you run green LED reports for any of your registered vehicles, they will not count toward the monthly-allotted reports, and they can give you valuable Staying Healthy information about your vehicle, including a list of Safety Recalls. If you own more than three vehicles and wish to register them all, you can add coverage for a nominal fee.
Q: What is a VIN and how do I find it?
A: The VIN is your Vehicle Identification Number. All vehicles are assigned one of these unique numbers. It’s usually a 17 character ID commonly found on the driver’s side interior dash, as well as on title records. Click here to see the common places VINs are located.
Q: Why do I need to provide my VIN and mileage to get a CarMD report?
A: The CarMD database has hundreds of thousands of repairs in it. We base our “most likely fix” on much more than just the code pulled from your car. To find the right repair your vehicle we need to know the year, make, model, mileage, engine and transmission type and the trouble codes found in your car’s computer. In many cases, this information is automatically pulled from your car by the CarMD handheld device. But in some cases we rely on you to provide us with accurate information, much of which is accessible thanks to your vehicle identification number, or VIN. Thanks in advance for helping us to help you!
Q: This tool comes with software. Do I have to use it?
A: No, but it’s highly recommended to get the most benefit from the product. The CarMD handheld tester is extremely valuable when used independently. However, you can get even more information when using the handheld device/software/information system together. It is the web-based information that provides consumers with the true value-added data, including easy-to-understand trouble code definitions, probable causes, fixes, estimated repair costs, list of safety recalls, and more. If you don’t have access to a computer and Internet connection, CarMD may not be the best choice for you.
Q: I bought or sold my vehicle. How do I add or delete a vehicle to my account?
A: To add a vehicle to your account you must first use the CarMD on the vehicle you are looking to add. After you have successfully linked the tool you would then go to your computer and connect it via the USB cable. It will open a page where you will be able to log on to your account. After you have logged on you will get a page where you can either choose a vehicle that has already been added or an option to add a new vehicle. Click on the button that says, “Add New Vehicle” and enter your VIN. To delete a vehicle simply click the “delete vehicle” button next to the vehicle you wish to remove. You are allowed to delete 1 vehicle from your account during a 365-day calendar period, which starts on the day you make your request. Please be aware that once you delete a vehicle you will not be able to activate it again. You will still have access to view / reference the archived reports for your vehicle even after it’s been deleted. If you wish to delete more than one vehicle during the same calendar year, please contact our customer service line at 1.888.My.CarMD (888-692-2763) Monday to Saturday from 6 am – 6 pm (Pacific Time).
Q: Could connecting this tool damage my car or PC in any way?
A: No. The CarMD tool and technology are completely safe for use on both your vehicle and personal computer.
Q: What are the minimum system requirements for using the CarMD software?
A: CarMD works under the following environments:
- Windows® System Requirements: - Macintosh® System Requirements:
  • Windows 2000, Windows XP, Vista (32- / 64- bit)
  • 50 MB of free hard disk space
  • 128 MB RAM
  • Pentium III processor
  • CD-ROM
  • 1 USB port
  • Internet connection
  • Internet Explorer 5.5, Netscape 7.0 or Firefox 1.0 browser
  • MacOS X (10.4.4 and newer)
  • 100 MB of free hard disk space
  • 256 MB RAM
  • Intel, PowerPC G3, G4, or G5 processor running at 700 Mhz or more
  • CD-ROM
  • 1 USB port
  • Internet connection
  • Safari 3.0, Netscape 7.2 or Firefox 3.0 browser
Q: Will CarMD work if my car won’t start or the battery is dead?
A: CarMD was initially designed to help provide solutions to powertrain problems associated with a vehicle’s computerized systems. In other words, it is for problems that cause the "check engine" light to illuminate, and related issues. This translates into the ability to diagnose about 80 percent of the systems on your car. In order to interface with your car’s computer, the CarMD handheld device needs a little “juice.” If your car’s battery is completely dead, it may not be able to do its job. CarMD also does not currently diagnose all non-starting vehicle conditions and codes. That said, CarMD is always working to add new features and benefits to our products, and pass them along to our customers. We recently added the ability to read and analyze ABS (Antilock Brake System) and SRS (Supplemental Restraint System) codes with newer model products, and are working on solutions to diagnose no-start issues. We encourage you to check the www.CarMD.com website for the latest information on the availability of this future upgrade.


General ordering questions

Q: What countries does CarMD.com ship to?
A: Our products ship to:
  • Continental United States
  • Alaska
  • Hawaii
  • Puerto Rico

We do not ship to any other states/provinces/countries outside that list, which includes:
  • Guam
  • The Virgin Islands of the United States
  • Etc

The CarMD® Vehicle Health System™ was designed to work with vehicles that are manufactured for exclusive distribution within the U.S. (this includes imported and domestic vehicles). These vehicles are required by United States law to be OBD 2 compliant – the CarMD tool will not work without this government-mandated technology. Vehicles distributed outside of the US may not comply with this requirement.
Q: What shipping methods do you offer in the U.S.?
A: Under normal conditions, CarMD offers FedEx Smart Post and FedEx 2nd Day as requested on your order (please see below for delivery availability). Please note that FedEx SmartPost shipments originate with FedEx but are delivered by the United States Postal Service.
Q: What are your shipping charges in the U.S.?
A: The list below provides shipping charges and delivery times for the first CarMD unit ordered. If you order more than one product at the same time you place your initial order, an additional nominal fee will apply for the additional product(s). Please note, that if you place an additional order on a different day, the same initial shipping charges apply, as per the list below, and additional nominal fee, if ordering more than one product at the same time.
CarMD.com reserves the right to request additional identification to process your shipment. If this is needed, we will contact you by e-mail or telephone.

NOTE: Shipments to US Territories, Alaska, and Hawaii will incur additional shipping & handling charges. We currently cannot ship to APO addresses.
  • STANDARD SHIPPING (FedEx SmartPost)
    CarMD.com offers Standard Shipping at a rate of $14.95 to ship to the continental United States and $29.95 for Alaska, Hawaii, and Puerto Rico for the first item ordered. Because of the recent high demand for CarMD, please allow two (2) to four (4) WEEKS to receive your order. Please allow one (1) additional week for PO Box shipments.
  • EXPRESS(rush) SHIPPING (FedEx 2-Day)
    CarMD.com offers Express Shipping at a rate of $34.95 to ship to the continental United States and $49.95 for Alaska, Hawaii, and Puerto Rico for the first item ordered. Because of the recent high demand for CarMD, please allow two (2) to four (4) WEEKS to receive your order. EXPRESS delivery is NOT available to all other US Territories as stated above but available to PO Box shipments only after the payment is cleared.
Q: Will I be charged for Sales Tax?
A: All California residents who purchase from CarMD.com are subject to an 8.0% state sales tax, or wherever sales tax is applicable.
Q: How can I check the status of my order?
A: To check your order status please click here.


Questions On Setting Up and Using CarMD

Q: Why do I get the “Err1” message on the CarMD handheld device?
A: The “Err1” message indicates that the CarMD handheld tool was not able to establish a link with the vehicle’s computer. Check the cable connections at the vehicle’s Data Link Connector (DLC). Turn the ignition off, wait 10 to 12 seconds, then turn the ignition back on to reset the vehicle’s computer.
NOTE: If you continue to receive the “Unable to establish link” message, try starting the vehicle first, then connect the CarMD tool to the vehicle’s DLC with the engine running. If the condition continues, it may be necessary to return the CarMD device to CarMD.com Corp. for an update to the firmware (please contact our technical support team at toll-free 888.MyCarMD (888.692.2763) for additional information). If you are still unable to link to your vehicle after performing these steps, please contact our technical support team for additional assistance.
Q: I’m having trouble linking the CarMD Handheld Tester to some vehicles manufactured by Volkswagen.
A: Volkswagen has an issue with communication when the vehicle has an aftermarket alarm or radio installed. This issue is not limited to CarMD tools, but occurs with all code readers and scan tools on the market. Consult your local Volkswagen dealership or Service Center for the proper testing procedures in this case. Or, you can consider purchasing an OBD2 extension cable online at www.CarMD.com.
Q: I’m having trouble linking the CarMD Handheld Tester to some vehicles manufactured by Subaru.
A: If you have trouble linking the CarMD tool to a Subaru vehicle, try starting the vehicle first, then connect the CarMD device to the vehicle’s DLC with the engine running. If the condition continues, please contact our technical support team at toll-free 888.MyCarMD (888.692.2763) for additional information. To try and resolve the problem, we recommend purchasing an OBD2 extension cable online at www.CarMD.com. If that does not resolve your problem, we may also need to have you return the tool for an upgrade.
Q: How do I register the CarMD unit for the first time?
A: When you access the CarMD website using the CarMD Tester, the Registration/Login page displays. If you are accessing the CarMD website for the first time, create your account as follows:
NOTE: If you have already created a CarMD Account, you can login to your account from the Registration/Login page.
  • Turn on your computer and make sure you are connected to the Internet before continuing.
  • Select an open USB port to your computer and connect the male end of the included USB cable to your computer. Please note that the connector only fits one way.
  • Connect the other end of the USB cable to the CarMD handheld tester. The CarMD software will launch automatically.
  • Follow the on-screen prompts. You will be automatically connected to the registration page within the CarMD website.
  • Click the Register Now button. The Create a New Account form displays.
  • Enter the following information in the Create a New Account form. All fields are required.
  • Enter you name in the First Name and Last Name text boxes
  • Enter your address in the Address 1, Address 2 and City, Postal Code and Country text boxes; select your State from the drop-down menu.
  • Enter your email address in the Email Address text box (Note: Only one CarMD account can be registered for any given email address).
  • Enter a personal password in the Password and Re-Enter Password textboxes (Note: Your password can be a maximum of 18 characters long. You may use both alphabetic and numeric characters).
  • Enter your telephone number in the Phone Number text box.
  • When all information has been entered, click the Save button to complete your registration. (Note: If your registration is not successful, an error message shows at the top of the Create a New Account form. Re-enter your personal information as needed, then press the Save button again.)
  • When your registration is successful, the Add Vehicle screen displays.

(Note: You can edit your personal information at any time by clicking the My Profile button in the CarMD Toolbar. You can change your personal password at any time by clicking the Change Password button in the CarMD Toolbar).
Q: What if I can’t get to a computer but want to get my CarMD vehicle diagnostic report?
A: You’re in luck; peace of mind is just a phone call away. A staff of ASE Certified technicians trained to answer your questions or give you a complete diagnosis when you just can’t get to computer supports CarMD. You can call from the used car lot or your road trip. Just be sure it’s a vehicle you’ve previously registered online. Just have your CarMD tester and VIN# ready and contact us toll-free at 888.MyCarMD (888.692.2763) Monday – Saturday from 6 a.m. – 6 p.m. (Pacific time).
Q: What if the CarMD database doesn’t have an answer (cure) for my vehicle’s problem?
A: If for any reason CarMD hasn’t seen your vehicle’s particular scenario, the company guarantees that its network of ASE-certified technicians will research the problem and provide you with an updated report, featuring most likely fix, and associated parts and labor costs to have the repairs made, within 5 business days.
Q: Why do the icons continue to flash on the upper left portion of the handheld tool’s monitor?
A: These little icons may not look like much, but they are providing you with a glimpse of what’s going on with the most important emissions-related monitors inside your vehicle’s computer. These I/M MONITOR STATUS icons represent Monitors inside each vehicle’s computer. Monitors are special programs used by the vehicle’s computer to verify proper operation of specific emissions-related components or systems (Oxygen Sensor, Catalytic Converter, EGR Valve, Fuel System, etc.). If a Monitor icon is flashing on the front screen of your CarMD tool, it indicates the associated Monitor is currently in “HAS NOT RUN” status.
A Monitor will not run until the proper set of conditions required to enable it to perform the self-diagnosis and testing of its assigned engine system have occurred. When a Monitor icon is solid, it indicates the associated Monitor is currently in “HAS RUN” status; the Monitor was able to meet all the conditions required to enable it to perform and complete the self-diagnosis and testing of its assigned engine system. When the conditions are met to allow each monitor to run during a single trip (of multiple subsequent trips), it is called performing a Drive Cycle. Put simply, if a monitor is flashing, it can mean the vehicle recently had work performed and needs to be driven to reset the monitors or the vehicle’s computer noted something it didn’t like that may trigger the check engine light to come on later. If these icons are flashing, it is unlikely that the vehicle will pass its emission test.
Monitor Icon Monitor Name Description of Monitor
Misfire Monitoring This Monitor continuously checks for engine misfires. A misfire occurs when the air-fuel mixture in the cylinder does not ignite. The misfire Monitor uses changes in crankshaft speed to sense an engine misfire. When a cylinder misfires, it no longer contributes to the speed of the engine, and engine speed decreases each time the affected cylinder(s) misfire. The misfire Monitor is designed to sense engine speed fluctuations and determine from which cylinder(s) the misfire is coming, as well as how bad the misfire is.
Fuel System Monitoring This Monitor uses a Fuel System Correction program, called Fuel Trim, inside the on-board computer. Fuel Trim is a set of positive and negative values that represent adding or subtracting fuel from the engine. This program is used to correct for a lean (too much air/not enough fuel) or rich (too much fuel/not enough air) air-fuel mixture. The program is designed to add or subtract fuel, as needed, up to a certain percent. If the correction needed is too large and exceeds the time and percent allowed by the program, the computer indicates a fault. The Fuel System Monitor may be a "One-Trip" or "Two-Trip" Monitor, depending on the severity of the problem.
Comprehensive Component Monitoring This Monitor continuously checks all inputs and outputs from sensors, actuators, switches and other devices that provide a signal to the computer. The Monitor checks for shorts, opens, out of range value, functionality and "rationality."
Catalyst Monitoring The catalytic converter is a device that is installed downstream of the exhaust manifold. It helps to oxidize (burn) the unburned fuel (hydrocarbons) and partially burned fuel (carbon monoxide) left over from the combustion process. To accomplish this, heat and catalyst materials inside the converter react with the exhaust gases to burn the remaining fuel. Some materials inside the catalytic converter also have the ability to store oxygen, and release it as needed to oxidize hydrocarbons and carbon monoxide. In the process, it reduces vehicle emissions by converting the polluting gases into carbon dioxide and water.

The computer checks the efficiency of the catalytic converter by monitoring the oxygen sensors used by the system. One sensor is located before (upstream of) the converter; the other is located after (downstream of) the converter. If the catalytic converter loses its ability to store oxygen, the downstream sensor signal voltage becomes almost the same as the upstream sensor signal. In this case, the monitor fails the test.

The Catalyst Monitor is a "Two-Trip" Monitor. If a fault is found on the first trip, the computer temporarily saves the fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the computer commands the MIL "On" and saves the code in its long-term memory.
Heated Catalyst Monitoring Operation of the "heated" catalytic converter is similar to the catalytic converter. The main difference is that a heater is added to bring the catalytic converter to its operating temperature more quickly. This helps reduce emissions by reducing the converter's down time when the engine is cold. The Heated Catalyst Monitor performs the same diagnostic tests as the catalyst Monitor, and also tests the catalytic converter's heater for proper operation. This Monitor is also a "Two-Trip" Monitor.
Evaporative System Monitoring OBD 2 vehicles are equipped with a fuel Evaporative system (EVAP) that helps prevent fuel vapors from evaporating into the air. The EVAP system carries fumes from the fuel tank to the engine where they are burned during combustion. The EVAP system may consist of a charcoal canister, fuel tank cap, purge solenoid, vent solenoid, flow monitor, leak detector and connecting tubes, lines and hoses.

Fumes are carried from the fuel tank to the charcoal canister by hoses or tubes. The fumes are stored in the charcoal canister. The computer controls the flow of fuel vapors from the charcoal canister to the engine via a purge solenoid. The computer energizes or de-energizes the purge solenoid (depending on solenoid design). The purge solenoid opens a valve to allow engine vacuum to draw the fuel vapors from the canister into the engine where the vapors are burned. The EVAP Monitor checks for proper fuel vapor flow to the engine, and pressurizes the system to test for leaks. The computer runs this Monitor once per trip.

The EVAP Monitor is a "Two-Trip" Monitor. If a fault is found on the first trip, the computer temporarily saves the fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the PCM commands the MIL "On," and saves the code in its long-term memory.
NMHC Monitoring The NM or NMHC (non-methane hydrocarbon catalyst) is a type of catalytic converter. It helps to remove non-methane hydrocarbons (NMH) left over from the combustion process from the exhaust stream. To accomplish this, heat and catalyst materials react with the exhaust gases to convert NMH to less harmful compounds. The computer checks the efficiency of the catalyst by monitoring the quantity of NMH in the exhaust stream. The monitor also verifies that sufficient temperature is present to aid in particulate matter (PM) filter regeneration.

“Compression ignition” vehicles support the NMHC Monitor only. The NMHC Monitor is a “Two-Trip” Monitor. If a fault is found on the first trip, the computer temporarily saves the fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the computer commands the MIL “On,” and saves the code in its long-term memory.
NOxAdsorber Monitoring NOx Aftertreatment is based on a catalytic converter support that has been coated with a special wash coat containing zeolites. NOx Aftertreatment is designed to reduce oxides of nitrogen emitted in the exhaust stream. The zeolite acts as a molecular "sponge" to trap the NO and NO2 molecules in the exhaust stream. In some implementations, injection of a reactant before the aftertreatment purges it. NO2 in particular is unstable, and will join with hydrocarbons to produce H2O and N2. The NOx Aftertreatment Monitor monitors the function of the NOx Aftertreatment to ensure that tailpipe emissions remain within acceptable limits.

The NOx Aftertreatment Monitor is supported by “compression ignition” vehicles only. The NOx Aftertreatment Monitor is a “Two-Trip” Monitor. If a fault is found on the first trip, the computer temporarily saves the fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the computer commands the MIL “On,” and saves the code in its long-term memory.
Secondary Air System Monitoring When a cold engine is first started, it runs in open-loop mode. During open-loop operation, the engine usually runs rich. A vehicle running rich wastes fuel and creates increased emissions, such as carbon monoxide and some hydrocarbons. A Secondary Air System injects air into the exhaust stream to aid catalytic converter operation:
  • It supplies the catalytic converter with the oxygen needed to oxidize the carbon monoxide and hydrocarbons left over from the combustion process during engine warm-up.
  • The extra oxygen injected into the exhaust stream also helps the catalytic converter reach operating temperature more quickly during warm-up periods. The catalytic converter must heat to operating temperature to work properly.


The Secondary Air System Monitor checks for component integrity and system operation, and tests for faults in the system. The computer runs this Monitor once per trip.

The Secondary Air System Monitor is a "Two-Trip" monitor. If a fault is found on the first trip, the computer temporarily saves this fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the computer commands the MIL "On," and saves the code in its long-term memory.
Oxygen Sensor Monitoring The Oxygen Sensor monitors how much oxygen is in the vehicle's exhaust. It generates a varying voltage of up to one volt, based on how much oxygen is in the exhaust gas, and sends the signal to the computer. The computer uses this signal to make corrections to the air/fuel mixture. If the exhaust gas has a large amount of oxygen (a lean air/fuel mixture), the oxygen sensor generates a "low" voltage signal. If the exhaust gas has very little oxygen (a rich mixture condition), the oxygen sensor generates a "high" voltage signal. A 450mV signal indicates the most efficient, and least polluting, air/fuel ratio of 14.7 parts of air to one part of fuel.

The oxygen sensor must reach a temperature of at least 600- 650°F, and the engine must reach normal operating temperature, for the computer to enter into closed-loop operation. The oxygen sensor only functions when the computer is in closed-loop. A properly operating oxygen sensor reacts quickly to any change in oxygen content in the exhaust stream. A faulty oxygen sensor reacts slowly, or its voltage signal is weak or missing.

The oxygen sensor is a "Two-Trip" monitor. If a fault is found on the first trip, the computer temporarily saves the fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the computer commands the MIL "On," and saves the code in its long-term memory.
Oxygen Sensor Heater Monitoring The Oxygen Sensor Heater Monitor tests the operation of the oxygen sensor's heater. There are two modes of operation on a computer-controlled vehicle: "open-loop" and "closed-loop." The vehicle operates in open loop when the engine is cold, before it reaches normal operating temperature. The vehicle also goes to open-loop mode at other times, such as heavy load and full throttle conditions. When the vehicle is running in open loop, the oxygen sensor signal is ignored by the computer for air/fuel mixture corrections. Engine efficiency during open-loop operation is very low, and results in the production of more vehicle emissions.

Closed-loop operation is the best condition for both vehicle emissions and vehicle operation. When the vehicle is operating in closed-loop, the computer uses the oxygen sensor signal for air/fuel mixture corrections.

In order for the computer to enter closed-loop operation, the oxygen sensor must reach a temperature of at least 600°F. The oxygen sensor heater helps the oxygen sensor reach and maintain its minimum operating temperature (600° F) more quickly, to bring the vehicle into closed-loop operation as soon as possible.

The Oxygen Sensor Heater Monitor is a "Two-Trip" Monitor. If a fault is found on the first trip, the computer temporarily saves the fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the computer commands the MIL "On," and saves the code in its long-term memory.
EGR System Monitoring The Exhaust Gas Recirculation (EGR) system helps reduce the formation of Oxides of Nitrogen during combustion. Temperatures above 2500°F cause nitrogen and oxygen to combine and form Oxides of Nitrogen in the combustion chamber. To reduce the formation of Oxides of Nitrogen, combustion temperatures must be kept below 2500°F. The EGR system re-circulates small amounts of exhaust gas back into the intake manifold, where it is mixed with the incoming air/fuel mixture. This reduces combustion temperatures by up to 500°F. The computer determines when, for how long, and how much exhaust gas is re-circulated back to the intake manifold. The EGR Monitor performs EGR system function tests at preset times during vehicle operation.

The EGR Monitor is a "Two-Trip" Monitor. If a fault is found on the first trip, the computer temporarily saves the fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the computer commands the MIL "On," and saves the code in its long-term memory.
Boost Pressure System Monitoring The boost pressure system serves to increase the pressure produced inside the intake manifold to a level greater than atmospheric pressure. This increase in pressure helps to ensure compete combustion of the air-fuel mixture. The Boost Pressure System Monitor checks for component integrity and system operation, and tests for faults in the system. The computer runs this Monitor once per trip.

The Boost Pressure System Monitor is supported by “compression ignition” vehicles only. The Boost Pressure System Monitor is a “Two-Trip” Monitor. If a fault is found on the first trip, the computer temporarily saves the fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the computer commands the MIL “On,” and saves the code in its long-term memory.
Exhaust Gas Sensor Monitoring The exhaust gas sensor is used by a number of systems/monitors to determine the content of the exhaust stream. The computer checks for component integrity, system operation, and tests for faults in the system, as well as feedback faults that may affect other emission control systems.

The Exhaust Gas Sensor Monitor is supported by “compression ignition” vehicles only. The Exhaust Gas Sensor Monitor is a “Two-Trip” Monitor. If a fault is found on the first trip, the computer temporarily saves the fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the computer commands the MIL “On,” and saves the code in its long-term memory.
PM Filter Monitoring The particulate matter (PM) filter removes particulate matter from the exhaust stream by filtration. The filter has a honeycomb structure similar to a catalyst substrate, but with the channels blocked at alternate ends. This forces the exhaust gas to flow through the walls between the channels, filtering the particulate matter out. The filters are self-cleaning by periodic modification of the exhaust gas concentration in order to burn off the trapped particles (oxidizing the particles to form CO2 and water). The computer monitors the efficiency of the filter in trapping particulate matter, as well as the ability of the filter to regenerate (self-clean).

The PM Filter Monitor is supported by “compression ignition” vehicles only. The PM Filter Monitor is a “Two-Trip” Monitor. If a fault is found on the first trip, the computer temporarily saves the fault in its memory as a Pending Code. The computer does not command the MIL on at this time. If the fault is sensed again on the second trip, the computer commands the MIL “On,” and saves the code in its long-term memory.