Snapshot General Description

PURPOSE OF SNAPSHOT
The Powertrain Control Module (PCM) snapshot feature is designed to assist in diagnosis of intermittent or unrepeatable problems. When a PCM snapshot is taken, all of the PCM's data and input parameters from that moment in time are stored for retrieval through the on-board diagnostic system and use in diagnosing a problem. PCM snapshots are taken in two instances; when most codes are set, or when Take PCM Snapshot is commanded in on-board diagnostics.

CODE SET VS. CUSTOMER SNAPSHOTS
Snapshots on code set differ from Customer Snapshots (refer to Customer Snapshot for additional information) 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.

ACCESSING SNAPSHOT
All PCM snapshot data may be accessed through the PCM Snapshot option in on-board diagnostics. The PCM snapshot selection is used for three things:

^ To record a snapshot while in diagnostics.
^ To retrieve snapshot data recorded while in on-board diagnostics.
^ To retrieve PCM code snapshot data.

PCM SNAPSHOT ON CODE SET
When a Powertrain Control Module (PCM) Diagnostic Trouble Code (DTC) 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 code trouble trees 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. Snapshot data will only be saved for the most recent set code.

RETRIEVING SNAPSHOT DATA
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.