Freeze Frame Data
Government regulations require that engine operating conditions be captured whenever the MIL is illuminated. The data captured is called the 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 operating conditions is recorded as the Freeze Frame data. A subsequent failure will not update the recorded operating conditions.The Freeze Frame data parameters stored with a DTC failure include the following:
^ 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 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 takes precedence over any data associated with any other fault. The Freeze Frame data will not be erased unless the associated history DTC is cleared.