For years’ cars were very simple. Carbs and valves were the most complicated technologies under the hood. This all started changing in the 1980s with electronic fuel injection systems, and integration of the car’s electrical system with the engine.
These days almost all cars have a sort of electronic ‘’brain’’ inside that does everything from regulating lights and fuel use to exactly how much gasoline gets sprayed into the engine during combustion. Of course, as soon as this happened, tuners began tweaking and molding these systems to try and achieve maximum performance from them.
It also became possible for this ‘’brain’’ or car computer system to monitor the systems in the car, and if something wasn’t working correctly it could send a sort of error code out to anyone who could read it.
For years, this was only available at dealerships, but soon these machines made their way out into civilian use. Even now you can go to a community auto parts store like an Auto Zone or a Pep Boys, and they will have the scanners needed to read these types of codes. You can of course also purchase them yourself.
Here in this article we’ll teach you how to plug them in and use them, and hopefully save you lots of money. Once you know what’s wrong with your car, you can fix it yourself, or take it to a third-party repair shop that will undoubtedly charge you less than the authorized dealer.
Heck, sometimes it’s just good to be able to walk into an auto repair shop and say, ‘’yeah, I need my #2 spark plug changed, it’s not firing right according to OBD Code 182’’ instead of saying ‘’uhh, my car is kind of moving slow, can you look at it?’’
This sounds a bit silly, but first you’re going to have to figure out where to plug in the OBD. Luckily if you’re at an AutoZone or similar, the manager or worker might know where the plug is on your particular make of car simply because he or she may have done it before.
If you’re not that lucky, here goes: look on the driver’s side under the dash. Usually the plugs live up high, not down by the pedals but up higher, near your knees. A good clue will be the size and number of prongs of the plug; if they’re the same as the prongs on the plug of the OBD you’re in business.
Sometimes, depending on the make and model of the vehicle you may need to look for the plug under the hood, or even possibly in the trunk. The final thing you’ll probably have to do; turn the car on! Most all car computers can only run if the car is actually on, so turn the key and give ‘er some gas.
Now comes the fun part; actually, finding out what’s going on with the car. Usually there may be some sort of ‘idiot light’ like a ‘check engine’ light flashing, or there may be an electronic menu in the dash console or near where your speedometer or mileage data is located. Either way, as you’re learning, the ‘’check engine’’ warning is only part of the story.
Once you plug in the OBD, it will start flashing a code. For example, let’s say the code is P0138. Now you’ll want to either ask the worker at AutoZone of their OBD can interpret the code, or if you need to do additional research. These days, even if the OBD isn’t a full-featured model that can interpret the codes, all you’ll have to do is Google the code name/number, possibly cross-referenced with your vehicle.
In this case, the P0138 code is the code for a failed oxygen sensor in a Jeep. Here comes another pro tip; just because the OBD is reading a code for something like a failed oxygen sensor, it doesn’t mean that the oxygen sensor is actually broken. You have to act like a skeptic in these situations; act like a doctor!
The wires may not be working correctly, or the exhaust catalyst may be messed up, causing the 02 sensors to give bad readings. Either way, Google will probably have more answers for you in these specific cases. And now that you have a specific area of the car to look at, go ahead and take a peek around the oxygen sensor.
Do the wiring and harness connections around the oxygen sensor look OK? Look around for corrosion or fried connections. ‘’Battery funk’’ like you might see around the terminals of an old car battery isn’t a good look here.
Nor is any sort of burnt or messed up connections. It’s also a good idea to check for exhaust leaks as they mess up O2 sensor readings. Finally, of course, replace the O2 sensor with a new one, then fire up the OBD again.
It’s important to turn the car off and on again, and also to turn off the OBD and turn it on again. You want to ‘’clear all codes’’ at this point, and if there is a menu option to do that in your OBD, go ahead and do that now. Once you do that, see if the ‘’check engine’’ light or other assorted idiot light pops up again or not.
Obviously if there is not code or ‘’check engine’’ light, you’ve succeeded! If not, you’ve still got more detective work to do. If you need to find parts cheaper than at your dealer or at the
AutoZone/Pep Boys, you can usually find salvage yards that sell parts for pennies on the dollar. Another cool thing to remember is that AutoZone and many of these auto parts shops will let you use their OBD for free; you don’t have to buy parts exclusively from them.
If you head out to a salvage yard such as Pull-A-Part, and armed with the codes and parts you need, you may be able to find parts for almost nothing. You can then try the ‘’new-used’’ parts with the OBD later and see if they work.
Hopefully this hypothetical situation has helped you learn how to use the OBD! Happy saving money while keeping your car in good shape!