If you have any knowledge of On-Board-Diagnostics or OBDii then you know it is a system that monitors your vehicle's performance and will let the driver know of any problems via the 'Check Engine' light on the dashboard. All car, light truck and SUV manufacturers have been mandated to have this system installed in their vehicles since 1996. When problems with the vehicle's systems occur the on-board computer generates a code to let the driver diagnose the problem. This code can be read by connecting and OBDii scan tool to the vehicle's computer.
OBDii scan tools are available for use by any vehicle owner and come in a wide range of price and function. Professional mechanics usually have access to more sophisticated readers. Regardless of the type of code reader you have the way it is used is pretty much the same.
- To begin with you will generally need a cable to connect to a scanner or a PC with OBDii software. Most scanners are universal in that they will read the most common codes, but some of them may only work with certain vehicles so make sure that the scanner you have is compatible with your vehicle.
- Always make sure that the vehicle's engine is turned off before connecting your reader.
- Locate the OBDii system connection plug. If your vehicle is compliant with OBDii protocols it will have a female 16-pin connection plug typically near the center console on the driver's side. Different vehicles may have different locations like under the steering wheel, behind the ashtray, between the front seats or under the driver's seat. A quick check online should let you find the location for your particular vehicle if it isn't readily noticeable.
- Check the vehicle's connector plug to ensure that all the necessary pins are present. Most importantly that the #4 and #5 pin for grounding and the #16 pin for the battery power supply.
- Connect your OBDii scan tool to the vehicle's computer. Your cable with the 16-pin plug at one end should connect to the female port on your vehicle. Then connect the opposite end of your cable to your scanner.
- An alternative to a hand-held scanner is to connect to a PC that has OBDii software installed on it. You will need a cable with the 16-pin connector on one end with a USB connector on the other to hook up to your PC. Bluetooth connectors are also available for this application.
- Once you are connected it may take a short interval of time for the reader to initialize. Your scanner will check the vehicle's computer to determine which protocol is required and the make the connection. The scanner will read the malfunction code stored in your vehicle's computer and display it on the screen.
- To interpret the code you may have to consult the service manual for your vehicle although some scanners will provide information for basic codes. Some scanner manufacturers also provide access to programs that will interpret the code and provide repair procedures based on that code.
