PCM "SNAPSHOT" On Code Set

When a PCM code sets, the PCM does several things. Among them is to save useful data and input parameter information for service diagnosis. This information is referred to as "Snapshot on code set".

You will see references to Snapshot on code set or snapshot data and input parameters in many PCM DTC Flow Charts because this information can be useful in pinpointing a problem even if the problem is not present when the vehicle is in the service bay. Snapshots on code set differ from customer snapshots and on-board diagnostic snapshots in that only a few relevant data parameters are saved with a code snapshot.

For each code set, eleven data parameters and all twelve inputs are saved. Which eleven data parameters are saved varies based on the code set. Transaxle code snapshots generally contain transaxle related data parameters while fuel code snapshots generally contain fuel related data parameters.

If several codes are set, snapshots for the three most recently set codes will be saved. Snapshot on code set data may be retrieved through the PCM SNAPSHOT option. When PCM SNAPSHOT is selected, snapshots on code set will appear first in the order the codes were set, most recent first. Snapshots on code set appear as "PXXX SNAPSHOT" where "PXXX" is the PCM code number.

When a "PXXX SNAPSHOT" is selected, "PXXX DATA" will appear and if selected, will display data from immediately after the code was set. If "PXXX DATA" is not selected "PXXX INPUTS" will appear and if selected, will display input data from immediately after the code was set. Keep in mind that once "PXXX DATA" or "PXXX INPUTS" is selected, the parameter and input data displayed will look just like the normal PCM parameter and input data with the same parameter numbers except the parameters will not vary since it is displaying recorded data.