Failure Records are records in the PCM that contain the engine operating conditions present when a trouble code is stored and the MIL is illuminated. On GM vehicles, the PCM can store multiple records (i.e., the Aurora 4.0L V8 engine can store up to three records while other vehicles can store up to five records) and can update the records at any time. As each record is updated, the first record is dropped and the new failure event is recorded. These records are an enhancement of the OBD II Freeze Frame capture feature, but they can store data for any fault in memory (not just data for a MIL fault)
GM vehicles can store up to 5 Failure Records on some models. Each record is for a different code. It is also possible that there will not be Failure Records for every code if multiple codes are set. The four types of codes and their related characteristics are shown below:
Failure records store data about the operating conditions when the code was stored and the MIL was illuminated. The PCM can store multiple records and can also update these records at any time. Some vehicles can store up to 5 failure records. However, the Aurora with the Northstar 4.0L engine will only store up to 3 failure records.
The current engine operating conditions are recorded in the Failure Records buffer each time a test fails. As each record is updated, the first record is dropped and the new failure event is recorded.
The operating conditions for a diagnostic test that failed may include one or more of the following engine operating parameters: