AutelOBD2 Scanner MS309 Automotive Check Engine Code Reader, Check Emission Monitor Status, CAN Diagnostic Scan Tool for All OBDII Protocol Vehicles After 1996

This tool (and other tools like it) do NOT teach you to repair automobiles! Further, they do NOT allow you to pass most state inspection just be resetting codes. This tool will show you the current generic and manufacturer specific codes that have been triggered, as well as pending codes. It WILL reset the codes, INCLUDING the monitor codes, however, you can't make the car pass inspection by just resetting the codes. All of the, I/M Readiness," monitors MUST re-test and show, "Ready" before you can inspect the vehicle. This scanner WILL show I/M Readiness status, however, so you KNOW that he vehicle has re-run all of the required monitor tests AND PASSED them before you waste time trying to get your vehicle inspected only to fail the inspection.It is back-lit and the back light works well. It is built very well and should give YEARS of trouble free service is not overly abused. (Hey, we all drop stuff form time to time, and this little guy can take it) It is very easy to use and to navigate the menus.More often than not, when someone is considering purchasing this type of, "Stored Code," scanner, they are purchasing it because they have a, "Check Engine," light, (or MIL - Malfunction Indicator Light -same thing, just different terms for it), that they'd like to resolve, and often are addressing this before their vehicle inspection runs out. Though just resetting the codes will NOT help you pass inspection, it WILL help you to determine if repairs made are going to ALLOW you to pass inspection more quickly.Here's how:You read the codes, and PROPERLY DIAGNOSE the cause. After making what you believe to be the corrections needed to resolve the issue that caused the code(s), you use this to reset the ECU. Now, search the internet for your year, make and model vehicle and the term, "Drive cycle." For example, 2005 Subaru Forrester drive cycle."What you are looking for in the search results is instruction for driving the vehicle in such a way as to provide all of the operating conditions needed for all of your vehicle's I/M readiness monitor checks to complete their testing and report the status in the shortest time possible. Every manufacturer creates these, "Drive Cycle," routines so that the factory automotive technicians in the dealerships can make repairs and assure the vehicle's compliance with local emissions laws as quickly as possible.An example of a possible drive cycle (that I'm just making us as an example), might look like:"Allow vehicle to completely cool overnight. (All that really matters here is that the engine be stone-cold before beginning the drive cycle on that particular year make and model. Not all vehicles require this first step, or any other step I make up here. This is just and example) 1.) Start vehicle. 2.) Accelerate slowly to 30 MPH, and maintain speed for 45 seconds. 3.) accelerate slowly to 55 MPH and maintain speed for 30 seconds. 3.) slow to 40 MPH without using the brake or downshifting, and maintain speed for 45 seconds. 4.) Accelerate to 55 mph and maintain speed for 4 minutes. 5.) From 55 mph, come to a complete stop, and place the shift leaver into the "Park" position with your foot off he brake and off the accelerator within 30 seconds. 6.) Allow the engine to idle for 1 minute . . . " Etc.Some drive cycles are fairly involved, and some are very short and simple. None the less, if you can complete the drive cycle without the check engine light coming back on, that's a good sign. Now, follow the instructions that come with Autel MaxiScan309 to connect the unit. You'll have to shut the engine off. (In the industry we call this, "engine off - key out," as this eliminates any confusion about what position the key is in. If the key comes out, you're good) Put he key back in once connected, turn to the RUN position, and check the "I/M Readiness" codes.If all I/M Readiness indicators are reporting either, "OK," "Pass," or, "N/A" your car will now pass that portion of the state inspection. If any say they are incomplete, (I think this scanner says, "INC" for those if memory serves), you need to do the drive cycle again to get them to report. Some of the monitors will say, "N/A." That is FINE. Manufacturers have choices in how to approach emissions compliance on different models, and often several of the monitors do not need to be used, just so long as the ones the manufacturer DID choose to employ do enough testing to ensure compliance with Federal Regulations.One last tip, and this is a real important one. If you don't have the background to decipher diagnostic codes and interpret the likely causes of them, DON'T FRET! Let's say your 2010 Ford Whatchamacallit is throwing a P0442 code, as reported by the scanner. Just search the internet for, "2010 Ford Whatchamacallit P0442 code causes," and you will begin to find all of the information needed to further diagnose the fault, AND are also likely to read the most PROBABLE causes in many cases. Consider the information you find carefully, as there is not test information needs to pas in order to be posted on the internet! lol When you have done enough research about the code's appearance on YOUR specific vehicle, you will easily see trends that point to the most LIKELY causes too. From there, you can start researching how to accurately TEST each suspected part to find out if it really IS the cause or not. Before too long, you should be able to find the REAL cause, and PROVE the part defective for yourself so you are not performing unneeded repairs hoping a, "shot in the dark," will fix whatever is wrong.If you find this review and the other information helpful in full or in part, please click the "YES" box where it asks if it was helpful or not.

So first, let's be clear that this is not a replacement for the scanner at a dealer or top quality professional repair shop. But I consider this tool a basic necessity for anyone who wants to do some simple repairs or wants to have some information before taking the rig in for repairs. I have used this on my 2005 3.0 DOHC Sable and my 2003 5.4 Expedition so far. Sable results were very fast and complete. Expedition results were slower and not as complete, but very useful none the less.This tool makes getting basic readings from the computer easy. The most frequent problems are also easy to repair if you know what they are. This tool will tell you if your engine is running rough because of a vacuum leak. (It won't tell you where the leak is, but usually it is related to the PCV valve. If not, some poking around and wiggling of vacuum lines will often reveal the problem.) A vacuum leak is usually easy and cheap to repair yourself.This tool will tell you if your gas cap is bad. This is the most frequent reason the "check engine" light comes on. Again, a cheap, easy repair.This tool will tell you if the oxygen sensor is bad. If your gas mileage has gone terribly downhill, and the "check engine light has come on, chances are this is the problem. Having a tool to confirm this is very helpful. If you can replace a spark plug, you can replace an oxygen sensor (please use the right socket!!!!).Beyond these issues, it is helpful to walk into your favorite repair shop and report a problem and the trouble codes you have discovered. You are likely to get a much more accurate estimate of repair costs right away instead of having to wait (and often pay a lot!) for a shop diagnostic scan.This tool will more than pay for itself if you are able to do even one repair on your own. It is a great investment.

Works great, I had a lower model Autel scanner for about 5 years that died (I think it got wet actually), so I was pretty confident getting this one... Used it several times and it works fine across several vehicles, it reads and clears code and can read a handful of other sensors (or so it appears, all I have used it for is code reading), the information it gives is pretty generic but better than just a P0XXX code, you will still need a code guide or Google up the code to see how to fix the issue. For a quick, occasional use device, this is great and more than most people need... if you are more of a hobbiest, there is little that can beat the ELM327 BlueTooth OBD2 interfaces and an Android device though for the price. I bought both actually, I keep this scanner in my trunk (I delivery pizza part time, a lot of the kids that work for us have cars with "issues" and need some help once in a while) and a couple BT interfaces in my toolbox. For 20 bucks and change, this is a solid investment.

I purchased it just for reading Check Engine codes and to reset the Check Engine Light.Was having an exhaust system issue and usually just take my truck to the local parts store to put the code. Multiple bad experiences helped me to decide on getting my own scanner but I don't need a couple hundred dollar scanner with all the bells and whistles for my purpose.This scanner is highly recommended by a couple mechanics that I follow online.This scanner does more than I expected for the price. Not only does it give you a code and reset the Check Engine Light. It stores a snapshot of exactly what was going on when the Engine light came on.Because of the diagnostic snapshot info, I was able to figure out exactly what was wrong and make the correct repair. The snapshot, showed that my truck was running "rich" and saved me alot of time by addressing the exact issue and cut my troubleshooting time in half. I highly recommend this product for anyone that does the work on their vehicles and doesn’t need a high dollar scanner.