Freeze Frame and Failure Records

With all emission-related faults and when the PCM commands MIL (SERVICE ENGINE SOON) On, the PCM stores vehicle information into a memory called FREEZE FRAME. The freeze frame is a regulated requirement which allows for certain information to be stored. This information is data for a DTC that caused the MIL to illuminate for the first time. The Scan tool displays this information in the DTC MENU under the FREEZE FRAME FAILURE RECORDS directory as failure record "0". Failure Records record the same data plus additional information and stores it in failure records numbered one through five. When the total recorded failures exceeds six, the oldest failure will be removed and the most recent installed as #1 (first in, first out).

FREEZE FRAME 0 will store the following:
^ DTC#
^ Commanded A/F ratio
^ Calculated air flow
^ Calculated engine load
^ ECT
^ Barometric pressure
^ Base PWM Cyl. #1
^ Short Term FT
^ Long Term FT
^ MAP
^ RPM
^ Loop status
^ TP angle
^ Vehicle Speed
^ Odometer reading at FIRST failure (odometer is reset to 0 when codes are cleared)
^ Odometer reading at LAST failure (indicates the odometer miles the last time the DTC test failed).

If equipped with automatic transmission the following will also be stored:
^ TR switch - P/A/B/C
^ TFP switch - A/B/C
^ TFP Range
^ 1-2 shift solenoid
^ 2-3 shift solenoid
^ Trans. fluid temperature
^ TCC
^ Transmission ISS
^ Gear ratio

For most of the codes the freeze frame/failure record will also store:
^ O2S sensor 1
^ HO2S sensor 2
^ Ignition volts

Some DTCs, when set, will replace these parameters with specific data related to code stored. Those parameters will aid in specific DTC diagnosis.

The FREEZE FRAME/FAILURE records for PCM will record all of this information plus specific data related to the DTC. History record data will be erased from PCM memory during a code clear or after 40 warm-up cycles without any faults detected.