What is OBD II?
If your vehicle was manufactured after the mid-nineties, chances are that you have an OBD II diagnostics port installed.
It is normally found underneath the dashboard on the driver’s side, and looks something like this:
An example of a female OBD-II port. Photo: Alain Van den Hende
OBD, or on-board diagnostics, is a system in your car which monitors electronics and drivetrain systems in your car and reports if it detects a fault.
Components which the system monitors are things like emissions, mileage, speed and engine issues, and flashes the “check engine” light if there is a fault.
Should you need to find out specifically what is wrong with your car, you’ll need an OBD-II interface to extract the fault code.
OBD-II was borne out of the need to further refine and standardise fault codes.
There are two types of OBD-II connector: type A and type B.
Type A is meant for vehicles which use a 12V supply voltage, while type B is for vehicles using 24V supply.
What can I plug into the port? Can I diagnose my own car faults?
If you visit your dealer or local mechanic, they will have the necessary equipment to connect to your car’s diagnostics port and find out what ails it.
Some scanners produce just numeric codes, and a mechanic would have to consult the manufacturer’s manual to decode them.
A typical OBD-II handheld scanner.
More advanced scanners, however, are available to both official dealers and drivers who wish to do a spot of DIY-ing on their car.
If you’re the sort who likes to work up a sweat on weekends, be prepared to dive deep.
If you get your own OBD-II diagnostics kit, you’ll have to contend with not only deciphering the common fault codes, but also those manufacturer-specific ones.
Some cheaper ones are available on Lazada or Qoo10, ranging anywhere from $30 to $50, while more expensive ones can run you well over $200 for colour screens and Bluetooth wireless functionality.
What else can OBD-II diagnostics let me do?
Some brands make dongles that plug into your car’s diagnostics port to change, or remap, the car’s electronic control unit.
Remapping your ECU via the OBD-II port brings about several benefits like a bump in horsepower and torque, but may cause fuel economy to suffer as a result.
For fringe cases like this, it’s best to head to an authorised workshop who know what they are doing, rather than attempting to do so on your own.
