Using Snapshots in Global Diagnostic System (GDS)

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Overview

A snapshot is a recording of what a control module on the vehicle was receiving for information while the snapshot is being made. A snapshot may be used to analyze the data during the time a vehicle condition is current. This allows you to concentrate on making the condition occur, rather than trying to view all the data in anticipation of the fault. In GDS 2, snapshots are automatically recorded whenever the user views Module Diagnostics, Vehicle Diagnostics and/or Systems Diagnostics. Module Diagnostics includes DTC Data, Identification Information, Data Display, Control Functions and Configuration/Reset Functions. Vehicle Diagnostics includes Vehicle Wide DTCs. Systems Diagnostics includes Inspection/Maintenance Status and Inspection/Maintenance Information.

Snapshot Replay

The Snapshot Replay function allows reviews of previously recorded vehicle snapshot data. This information can be used in analysis of vehicle problems and detection of trigger error conditions. The graph function can be used to compare parameters to see if a component is functioning properly. Recorded snapshots can be selected for viewing by the following two methods:

From the Home Page, click on Review Stored Data. In the Snapshot Select Page, highlight the vehicle in the upper pane and highlight the desired snapshot in the lower pane, then click the Select Snapshot button.
The user can view a snapshot without ending a current on-vehicle diagnostic session by clicking the Module button (when active) or Back button until the Session Manager is displayed in the menu. This is used when a user is viewing live data and wants the quickest way to review the data. Click on the Session Manager button. Highlight the desired snapshot in the lower pane and click Select Snapshot

View Selections

The following information can be selected in the tabs at the top of the screen:

Line Graph - Displays information from the snapshot file in graph view. The current value of the parameters is displayed on the screen. Use the buttons on the right side to modify the graph data.
Diagnostic Data Display - Displays incoming information from the snapshot file. The current value of the parameters is displayed on the screen. Use the buttons on the right side to modify the data.
DTC Display - This tab will be displayed when a DTC is current or the status has changed. The tab will not be displayed when there are no DTCs.
Bookmarks - If bookmarks are present, this displays the Type, Description and Time of automatic and manually generated bookmarks.
System Information - Displays the GDS 2 Software Version and MDI Serial Number used when the snapshot was recorded.
Selected Vehicle Configuration - Displays vehicle options information.

Snapshot Replay Functions

To review the snapshot there are buttons at the bottom of the window to control the cursor. From left to right the buttons are:

Return to Frame 0 - This button returns the cursor to frame 0.
Stop - This button pauses or stops the cursor. Click the Play button to resume.
Play - This button starts the replay of the data.
Play Speed - This button changes the speed between 1x, 2x, 4x and 8x.
Back 1 Frame - This button moves the cursor back 1 frame.
Forward 1 Frame - This button moves the cursor forward 1 frame.
Previous Bookmark - This button moves the cursor to the previous bookmark.
Next Bookmark - This button moves the cursor forward 1 bookmark.