Aurora V6-214 3.5L VIN H SFI (2001)
DTCs and the related data that was stored originally if multiple DTCs were stored.
Selecting this option on the scan tool allows the technician to record the Freeze Frame and Failure Records that may be stored in the PCM memory. This
can be useful if the PCM or the battery must be disconnected and later review of the stored information may be desired.
Storing and Erasing Freeze Frame Data
Government regulations require that the engine operating conditions be captured whenever the MIL is illuminated. The data captured is called Freeze
Frame data. The Freeze Frame data is very similar to a single record of the operating conditions. Whenever the MIL is illuminated, the corresponding
record of the operating conditions is recorded to the Freeze Frame buffer.
Each time a diagnostic test reports a failure, the current engine operating conditions are recorded in the Freeze Frame buffer. A subsequent failure will
update the recorded operating conditions. The operating conditions for the diagnostic test which failed typically include the following parameters:
^
The air/fuel ratio
^
The air flow rate
^
The fuel trim
^
The engine speed
^
The engine load
^
The engine coolant temperature
^
The vehicle speed
^
The throttle position angle
^
The manifold absolute pressure and barometric pressure
^
The base pulse width of the fuel injection
^
The loop status
The Freeze Frame data can only be overwritten with data associated with a misfire or a fuel trim malfunction. The data from these faults take precedence
over any data associated with any other fault. The Freeze Frame data will not be erased unless the associated history DTC is cleared.
Storing and Erasing Failure Records Data
When a PCM DTC sets, the PCM does several things including saving useful data and input parameter information for a service diagnosis. This
information is referred to as the Freeze Frame and Failure Records. You will see references to the Freeze Frame and Failure Records in many PCM DTC
diagnostic tables 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. The Freeze Frame and Failure Records data may be retrieved through the DTC menu on the scan tool. If more than one DTC is set review the
odometer or the engine run time data located in the Freeze Frame and Failure Records info to determine the most current failure.
Keep in mind that once the Freeze Frame or the Failure Record is selected, the parameter and input data displayed will look just like the normal PCM
data except the parameters will not vary since stored data is being displayed.
PCM Snapshot Using A Scan Tool
The scan tool can be set up to take a snapshot' of the parameters available via the serial data. The Snapshot function records live data over a period of
time. The recorded data can be played back and analyzed. The scan tool can also graph the parameters singly or in combinations of parameters for
comparison. The snapshot can be triggered manually at the time a symptom is noticed, or set up in advance to trigger when a DTC sets. An abnormal
value captured in the recorded data may point to a system or a component that needs to be investigated further. The snapshot will remain in the scan tool
memory even after the tool is disconnected from a power source. Refer to the scan tool user instructions for more information on the Snapshot function.
