DTC or OBD2 codes are a vital part of any car as they are the key to diagnosing any minor or major issues. Most often they are used to narrow down the source of your car’s engine issues. Whenever your engine encounters a malfunction in its mechanisms it isolates it and saves it in the form of a code (also known as a DTC – diagnostics trouble code). This is where a good OBD scanner will come in handy. It will read the code for you and maybe even show you the code’s definition. From then on, it is up to you or your mechanic to look up that issue in the repair manual of the car and fix it accordingly.
Sadly, people don’t always have OBD scanners in their back pockets and car manufacturers know that. This is why they invented ways to allow you to check potential error codes via alternative methods. We will show you some of the most famous ones.
Using Your Ignition Key To Get OBD2 Codes
What does every driver have? That’s right – a key for the car. This is why car engineers came by this simple way to get OBD codes out of your vehicle. Turn the ignition key on and off a few times but don’t crank the engine. The number of times you have to do this depends on the type of car you own. Chryslers need five times while other cars like most Fords will need three or four. It is important to end this process on the “On” position. If you accidentally crank your engine just start all over.
Once you are done with this the “check engine” light will start blinking. Each blink represents a number and a pause separates the two numbers which will form the end code. For instance, a code 31 will look like this: blink, blink, blink, pause, blink. Once you have written down the codes given to you by the car check the car’s repair manual to see the meaning of each code (there can be way more than one codes).
An important thing to remember here is that those codes are different from the 5-symbol codes you get from an OBD2 scanner tool like the Autel MaxiSYS MS906 for example.
The Odometer Method
Try pressing the “Trip” and/or “Reset” buttons on your odometer while also turning on the ignition key. After that, release the odometer buttons and wait for it to display the trouble codes that will be written out on the dashboard display.
If this doesn’t work for your car try turning the ignition on and off while ultimately leaving it at its “On” position.
Pro Tip: Take your car to a local auto parts dealer. Most of these shops offer free car diagnostics while some may charge you a certain fee but they will have far more advanced scanners.
The “Paper Clip” Method
Most of the cars made after 1996 display their engine, brakes, airbag, and transmission error codes on the car’s dashboard. To generate this you can use a jumper wire plugged into the “A” and “B” ports of the OBD terminal. The most common jumper wire people use is an unbent paper clip. Make sure it isn’t plastic covered and is actually made out of steel. Straighten it out and insert its both ends into both the “A” and “B” ports.
Doing this will result in a code flashing on your dashboard either in a digital format or in the form of a warning light coming from the specific part that has an issue. This method is safe and isn’t actually something somebody found out by accident. It is a well-thought feature by the car’s engineers which ensures people can diagnose issues when there are no OBD scanners around.
As the light on your dashboard start flashing some cars will require you to turn the ignition on. Then, following the sequence method we previously explained you can get the number of the error code.
Using A Multimeter To Read Codes
For this method all you need is a standard digital multimeter. Reading the codes here is somewhat tricky but we will walk you through it. All that is needed from your multimeter is for it to be able to measure from 0 to 12 volts. You need to find the right polarity between the “A” and “B” ports and turn the ignition on. Once you do that the OBD port will start generating slight electrical impulses (from 0 to around 10 volts) which will be detected by your tool. Each impulse represents a signal which can be read following our sequence instructions. At the end you will have a code that can be found in the car’s repair manual.
We tried this method with even the cheapest multimeter and it worked just fine so don’t worry about the quality of your tool.
Some other methods include the “black jumper cable method” and the “LED tester method”. They don’t work on most car models, though, so that is why we didn’t present them in full details here.
If you want to learn more about the actual OBD2 codes and how to read and decipher them, check out our article on the topic.