At the time, most vehicles only had a handful of modules sharing data across this network. Back then, many of the legacy scan tools were unable to communicate with the new CAN standard unless hardware and software changes were implemented. Today, however, vehicles coming off the assembly line possess dozens of modules which may not all be on the same network or communicating using the same protocols. (Figure 3) In order for communication between them to take place, specialized modules are equipped with the hardware and software that allow them to act as a gateway device. This standard was implemented to help unify data communications between the various modules or nodes populating the vehicle. Controller Area Network (CAN)īeginning with 2008 models, the CAN protocol was mandated for all passenger vehicles and light trucks sold in the United States. Some tools can only read generic OBD-II standardized information, which might be fine, however, there could be more generic data the tool can't display. The same goes for tools possessing the ability to display OEM proprietary data: Some are more capable than others and your mileage may vary (more on that later). The different tools on the market all have their strengths and weaknesses, and technicians need to be aware of each tool’s capabilities in order to get to the bottom of a problem. For example, some tools may be very quick to connect to a vehicle and access the specific data the technician is laser-focused on. However, that specific tool may not be good at performing other functions, such as running a full vehicle scan or health check and producing a comprehensive report. Some tools are excellent at logging every action performed on the vehicle, which can be used to document how much time went into the analysis on the vehicle, in addition to providing module part numbers and software version levels. (Figure 1.) Service technicians need to have a good foundational knowledge base around how a particular scan tool works and what the limitations are.
Reflecting on this I can honestly say that we have come a long, long way. At that point in time, I realized that I needed to acquire and consume as much training as I possibly could, and to this day, that hasn’t stopped. My disappointment, however, was primarily my own fault for not having the proper service training on that vehicle system. Once I connected, I was disappointed to find that the live data stream found on the GM vehicle was not available on another domestic OEM. I remember trying to connect the same tool to another manufacturer and discovering that this operation required different adapters and software cartridges. Although the data stream was very cool, I had no idea as to how this information was being transmitted and displayed. I began to imagine how this was going to change the way the technician would be addressing certain vehicle anomalies and what the future of automobile service was going to look like. At the time, these new layers of technology presented the dawn of a new era and interesting challenges.
It was on a 1982 GM vehicle equipped with the Computer Command Control system. I remember one of the very first times I used a scan tool.