On-Board Diagnostic (OBD II) System/Protocol
OBDII protocol is a software technology inbuilt in cars from 1996 till date that helps in diagnostics and programming of such cars. Just as OBD I, sensors are incorporated into almost all components and systems in the vehicle depending on the model or brand. When these sensors discovers any alteration in its proper value range, its send signals (messages) to an inbuilt computer known as the ECU (Electronic Control Units) or ECM (Electronic Controlled Module) or Brainbox. The ECU (brainbox) then interprets this signal (usually voltage) and send this information to the dashboard or other system where the warning lights and alarms are located, and then to the Diagnostic Port where various interpretation of the various faults detected in the vehicle can be accessed. The messages from the computer inbuilt in the car can only be interpreted or reprogrammed using a diagnostic scanner or a code reader.
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The interpretation of this message is from the scanner may be difficult for a novice in automobile diagnostic technology, but modern scanner are designed for easy comprehension, software have been designed to help displayed this messages in computers and smartphones.
Diagnostic Scanners
The major tool in Automotive Technology is the Diagnostic Scanner, the kind of scanner you have determines the kind of diagnostic operation you can perform. There are various kinds of diagnostic tools and more types are evolving as technology improves, in fact In-built scanners are been introduced into vehicles where the user can operate from the dashboard.
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There are various classifications of diagnostic scanners of which includes;
ELM327
Hardware Interface
Hardware Interface with In-built software
Wireless Connection Interface
Display incorporated interface
ELM327
ELM327 one of the cheapest kind of diagnostic tool available in the market, it is a program that helps interpret fault codes through special software application in smartphones and laptops, they are either Bluetooth enabled or Wi-Fi enabled.
This little gadget can be useful in doing serious diagnostics when you understand it very well, but it’s primary purpose is to read fault codes and clear them. Like all diagnostic scanner, not all codes can be cleared by this device.
It is also limited in reading fault codes; it only read fault codes for Engine, Transmission and a few other components/systems.
ELM327 adaptor works with specific applications which are available in Windows, IOS and Android devices, there are also Symbian device version.
I will recommend the following Apps for you to use with your ELM327, I have tried them and they are some of the best App available.
- Torque Pro
- OBD Auto Doc
- Dashboard
- HobDrive
These Apps are available in Play Store and Apple Store.
Torque Pro: it’s considered the best Application for ELM327, in fact when I bought my ELM327 Adaptor, it was the App the manufacturer recommended for it.
(Note that you these Apps has in-app purchases.)
Torque is easy to display, you can use it for finding fault codes and clearing them, it also has a Dashboard that gives real time information, such as Throttle Speed, Coolant temperature and others. You can also create a vehicle profile and save test results.
OBD Auto Doc: Very similar to Torque in functions, as they perform same thing.
Dashboard: or Dashcommand it shows us real time information such as RPM, Power, Torque, Speed, Coolant Temperature, Mileage Rate, Fuel Economy and lots more. It also performs the normal function of testing for fault codes and erasing them. It gives various information over 60 of them, it also have more functions.
Limitations of ELM327
Firstly, before I mention the limitations of this device, I would want you to know that this device may be very useful to a car salesman, but might not be very useful to a professional Mechanic. The reason is because there majority of the information a car dealer or one who needs to purchase a used car need is available on the device. Whereas a mechanic may need more information that are not available in this device for some complex repairs jobs.
The ELM327 cannot perform the following diagnostic check on the electrical and electronics system which is the basis of diagnostic technology in modern vehicles.
Modern cars now have sensors in almost all parts; drivetrain, chassis, body, seat and doors, air-conditioning etc. So the ELM327 cannot be efficient in having complete diagnostics of all sensors and systems in modern vehicles.
Also there are a lot of cloned ELM327 in the market, this clones are usually very cheap and are limited in diagnosing more advanced cars.
ELM327 is of various versions, have an old version device may not allow you to successfully diagnosed a recent car model.
Finally, car manufacturers are now providing stringent conditions for diagnosing of their brands, thereby enabling only their authorized devices and applications to effectively diagnose their product, and this is a stumbling block from many simple diagnostic tools. Get your Automotive Diagnostics Tools.
With these limitations of ELM327 it doesn’t make it a useless device, but it only show us that we cannot solely rely on it for full-time diagnostics.
There are more advanced diagnostic scanning tools out there with more options which makes automobile diagnostic stress free, but the better the device the greater the cost.
