I was recently at a seminar going over some diagnostics for some of the problematic and reoccurring fault codes. The general discussion led us in an interesting direction about the nature of fault ...

An OBD-II scan tool is an incredibly useful automotive diagnostic device, but it's not magic. Here's what it can and can't do ...

Modern vehicles’ sophisticated electronics go far beyond the simple car mechanics most of us grew up with. Now, OBD, or on-board diagnostics, diagnoses almost every issue within your vehicle. Whether ...

Code readers are diagnostic tools that every car owner should consider owning. Having one of these is as important as carrying a spare tire or a fire extinguisher in the trunk. Back in the day, before ...

It is obvious—painfully so, to some—that vehicles have become considerably more dependent on electronics. We are all aware that performance gains on our new cars often aren't as easily obtainable as ...

If you've ever gone to a mechanic for a check engine light problem on your car, then chances are you've heard the technician say something about an OBD scanner. It's a handheld phone-like device that ...

In the January issue, we discussed the history of OBD. This time we are going to investigate some of the technology required to meet OBD II standards. To give an idea of the magnitude of technological ...

This article was updated in November 2025 with new information. You know you’ve earned your DIY stripes when you can stay calm the moment something goes wrong. And with cars, that moment usually ...

Code P0720 is one of the OBD codes that is activated when the Powertrain Control Module (PCM) detects erratic or insufficient input from the output shaft sensor (OSS). Such a code generally indicates ...