The days of opening the bonnet and taking a look around to see what could be going wrong with a vehicle are long gone when it comes to modern cars, trucks, and vans. With an on-board car diagnostic system, the vehicle notes the problem and stores the information in a computer for a technician, or you, to retrieve. The car diagnostic system can seem a bit overwhelming, but with a little knowledge, you can use the diagnostic tools yourself.
Vehicle Diagnostic Tools
The primary function of vehicle diagnostic tools is to interpret the data received from the OBD, or on-board diagnostic computer. With the correct vehicle diagnostic equipment, you can analyse all sorts of faults in your vehicle from the ABS system, to climate control, and even the electric seats. The tools work by scanning the system to find error codes, interpreting the error codes, and using software to integrate with your vehicle's computer, to locate and direct repair needs.
Vehicle Diagnostic Scanner
When the check engine light or gauge lights up, the powertrain control module is noting that data from one or more of the sensors in the vehicle is far enough out of bounds that the PCM does not know how to fix the problem. To use a diagnostic scanner, plug the tool into the OBD connector, which is usually behind the steering wheel under the control panel. The tool asks you questions that may include the vehicle's identification number, make, model of the vehicle, and the engine type. Follow the onscreen instructions carefully. Some scanner tools give a text explanation of the codes on the screen. Others may include a CD-ROM or a pamphlet listing what the codes mean.
Diagnostic Code Reader
To use a diagnostic code reader, plug it into the diagnostic link connector under the dashboard with the engine off. Engage the engine and follow the code reading procedure included with the instruction manual. The code reader produces a code that indicates where the problem with the vehicle is. Once you have the code, you can look up the code in a reference book or check your vehicle manufacturer's code list. In addition, you may receive an interpreter with some units. The codes inform you of where the problem is, allowing you to decide if the vehicle must go to the mechanic immediately.
Understanding Diagnostic Software
The OBD tracks emission related controls, engine performance, and the drivetrain to detect malfunctions. OBD diagnostic software communicates with the car and reads the diagnostic information the car produces. Located under the dash, you can find an adapter attached to the OBD port that acts as a bridge between your PC or Mac and your vehicle. The software communicates with your vehicle and presents diagnostic information in an easy to understand manner.