The word ‘diagnostic' originates from a Greek word that refers to the capacity or art of distinguishing. In the common sense of understanding, it refers to identifying the nature or cause of something, usually an illness, disorder, or problem. When we talk about vehicle diagnostics, the use of the term is still applicable.
In the past, working on a vehicle was not as computerised as it is nowadays. Mechanics and vehicle owners, who had the knowledge, could diagnose problems and work on these problems with only some basic tools to their disposal. This changed drastically. Due to an immense amount of electronic components, and a sophisticated computer that regulates most of the functions in the vehicle, diagnosing problems and fixing it require a decent amount of knowledge about electronics. Because of this high-tech state, we are not always able to detect the exact cause and location of a problem. This is where the diagnostic tool steps in to save the day!
Today's diagnostics tools are able to check every aspect of a vehicle, such as the engine control unit (ECU), performance, emissions, oil levels, temperature systems, etc. These diagnostic tools makes the task of diagnosis so much easier. When we refer to tools, in its plural form, we imply that there are more than one. We will look at the different types of diagnostic tools in use; we will also learn about what a vehicle diagnostic exactly entails.
It is very important, due to the immense amount of electronic components that regulate so many vehicle functions, to use the right diagnostic tool to detect and identify problems. According to Schueller (2015), there are mainly three types of scan tools available in the automotive aftermarket domain: the On-Board Diagnostic Level Two (OBD-II) generic and OBD-II enhanced tool and then there is the factory scan tool.
OBD is a standardized system that allows external electronics to interface with a vehicle's computer system with the primary purpose of performing a diagnostic test. When a vehicle's sensors detect an anomaly, it triggers a trouble code that may manifest as a “check engine” light or other dashboard warning. An OBD scanner can check these trouble codes to determine exactly what is wrong, and then clear them from the computer's memory once the problem is fixed. Many people – in our experience – have little knowledge about the meaning of these codes. Let us therefore quickly peek at these codes, by doing so the uninformed vehicle owner may have a better understanding of them.
According to autointhebox.com, each letter and number in the diagnostic trouble code can represent a different part of the vehicle. It is important to note that the digits mentioned here may vary by vehicle make, but usually they indicate the following. If the first letter is a “P”, it will refer to the power train. The letter “B” will relate to the body, a “C” to the chassis and a “U” is undefined. The number zero in the second placeholder is a generic code shared by most manufacturers, but some manufacturers may use a specific code here, the number 1 may then appear. The third placeholder determines the area of the problem. In this regard, the numbers may indicate the following:
1 – Fuel or air problem.
2 – Injector circuit issue.
3 – Ignition problem or engine misfiring.
4 – Emission control problem.
5 – A speed or idle control problem.
6 – A computer or output circuit problem.
7 and 8 – A transmission problem.
The fourth and fifth placeholders identify which system is malfunctioning.
There are many code readers available on the market and they are usually handheld devices specifically designed to detect common vehicle problems. The most commonly used code reader will provide the user with OBD-II generic information. There are different tiers to the capabilities of code readers, and there is a simple logic to follow here: the more expensive the code reader (scan tool), the more capabilities it will most likely have.
The factory scan tool, as mentioned earlier, is a tool specifically made by and for the original equipment manufacturer (OEM), which means that every OEM has its own factory scan tool. The best option is to opt for an OBD-II enhanced scan tool, because it can complete the diagnostic process on a wide range of makes and models. What makes the OBD-II enhanced model so attractive is that it includes bidirectional tests (actuator tests and adjustments) that the generic model cannot.
You may have a picture in your mind of a machine/scanner, be it a stationary or handheld one, used to diagnose the vehicle's ECU, and there it ends. What you may not know is that there are other types of diagnostic tools available. You may be acquainted with these but you may not know that they are also diagnostic tools in the true sense of the word. Let us have a look!