GM Testing - Snap-on

Chapter 8 <strong>GM</strong>
<strong>Testing</strong> Control Systems Tests (Except ABS)
CHOOSE A FAILURE RECORD OR FREEZE FRAME:
>P1406 (FREEZE FRAME)
P1406
P1577
Figure 8-15 Sample DTC display when Freeze Frame/Failure Records is selected
A DTC followed by (FREEZE FRAME) indicates an emissions-related DTC that meets OBD-II
freeze frame requirements. A DTC not followed by (FREEZE FRAME) indicates that the DTC
is either non-emissions related or is emissions-related but has not yet met the OBD-II freeze
frame requirements. The <strong>GM</strong> failure records may include more data than OBD-II freeze
frames. The scan tool displays both a freeze frame and a failure record selection for
emissions-related DTCs.
Selecting FREEZE FRAME/FAILURE RECORD displays a “please wait” message while the
data is loading, then the freeze frame and failure record displays (Figure 8-16).
FREEZE FRAME/FAILURE RECORD DATA
** CODES & DATA. OK TO DRIVE. **
P0201 CYLINDER 1 - INJECTOR CKT PROBLEM
ENGINE LOAD(%)_____0 COOLANT(°C)_____100
Figure 8-16 Sample freeze frame and failure record display
History
The HISTORY selection displays any history DTCs that are stored in PCM memory since the
last time DTCs were cleared (Figure 8-17).
CODE LIST
** CODES & DATA. OK TO DRIVE. **
P0122 TP SENSOR OR APP SENSOR 1 CKT SHRT
*** END OF LIST ***
Figure 8-17 Sample history display when codes are present
MIL SVS or Message Requested
The MIL SVS OR MESSAGE REQUESTED selection displays DTCs that are currently turning
on the MIL, SVS lamp, or displaying a message on the message console.
Last Test Failed
The LAST TEST FAILED selection displays DTCs that were detected when the last test was
run.
Test Failed Since Code Cleared
The TEST FAILED SINCE CODE CLEARED selection displays DTCs that set since the last
time codes were cleared.
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