MODE $01 Parameter Identification (PID) displays emission-related data PIDs such as inputs, outputs, and system status.  Pre-CAN global OBD II displayed between 15-30 PIDs.  For CAN systems the data list was expanded.  When using a global scan tool to diagnose the vehicle understand the amount of data available to view and that it will vary depending on the model year and communications protocol.

The following are three examples of what to expect for data PIDs.

1) This data list was captured from a 1997 pre-CAN vehicle. Because of the limited data displayed from some pre-CAN systems, many technicians chose to look at the manufacturer's (OE) specific data. In many but not all cases, this side of the scan tool displayed much more data.

2) This data list was captured from a 2003 pre-CAN vehicle. For later model pre-CAN systems, the data list provided enough data to diagnose many emissions-related problems, but the data list still needed to be expanded.

3) This data list was captured from a 2019 CAN-equipped vehicle. Because CAN systems transmit data at a much faster speed and in packets of 6 PIDs per request the data list was expanded. In this case, a technician had more help to diagnose more problems through the global side of the scan tool.

Regardless of the year vehicle, learn to customize the PID list to increase the speed at which they update their data. Focus on the need-to-know PIDs, not the nice-to-know PIDs. Think of it this way, you have a one-lane road and there are only 6 cars on the road moving at the same speed. The next time you drive that road there are 30 cars on the road moving at the same speed. Which one is faster to travel through?