Should I buy my own code reader or scanner?

All vehicles made since 1996 are equipped with an on-board computer that detects faults in the engine, transmission and emission systems and reports problems using indicators on the dashboard (such as the Check Engine light). There is also a connector located under the dashboard to which you can connect a code reader. This allows the mechanic to connect a reader or scanner to the vehicle and see which code is causing the lights to come on.

Should you buy your own?

You can buy code readers and scanners on the market relatively cheaply. They will connect to the OBD II connector under the dashboard and will be able to at least pull the code. However, this will not necessarily bring you much benefit. Fault codes are simply a series of letters and numbers that tell the mechanic what's going on, or what fault code to look for.

This means that if you don't have access to resources detailing what each DTC means, you're out of luck. You will know the code, but you won't get any closer to actually diagnosing the car. In addition, many fault codes are not decisive - they are general. You may find out that the problem is with your gas tank evaporation system, but that's all you know.

Another complication is that all cars have so-called manufacturer's own fault codes. This means that no code reader/scanner other than one programmed by the car manufacturer will be able to tell you what the code is. So in this case you won't even be able to tell what the problem is.

So, is it worth buying your own code reader? If you are a mechanic or former mechanic, this might make sense. This can also be a good option if all you need to do is turn off the Check Engine light to see if it comes back on. However, if you really want to fix the problem and don't have the resources other than a code reader, that money is better spent on a professional mechanic.