Freeze Frame and Failure Records
FREEZE FRAME/FAILURE RECORDSThe Scan tool displays vehicle malfunction history information accessed through the Diagnostic Trouble Code menu under the subheading Freeze Frame/Failure Records. A maximum of 10 records can be stored in the controller at any time; only one of which can be a freeze frame 'F0:' for an emission related DTC. Each diagnostic trouble code (DTC) will store two records for a maximum of five different DTC failure records. One failure record is the initial data parameters at the initial time the DTC set. and the second record is a record that updates every time the ECM passes the diagnostic, then fails it again.
NOTE: If a fault occurs and the ECM never passes the diagnostic (fault never corrects itself). the first record will be identical to the second. Once all of the Scan tool failure records are full, the records will NOT shift positions even if another DTC sets.
Government regulations mandate that all emission related DTCs store freeze frame data, designated as F0: FREEZE FRAME on the Scan tool at the time of the first failed test when a DTC initially sets. The first emission related fault that sets after a code clear or battery disconnect is stored in freeze frame and can only be overwritten by Fuel Trim and Misfire codes. All other emission related DTCs that set would not be stored in freeze frame unless the initial code is cleared.
NOTE: If a non-emission related DTC sets with no other codes set. the initial failure record at the time the non-emission related code sets will be displayed as Failure Record '0' on the Scan tool. However, the F0 position would be overwritten if an emission related fault occurred and a Freeze Frame was not already sitting in the F0 position.
The following is an overview of DTC types and how information is stored in memory.
EMISSION RELATED
TYPE A First fault during first ignition cycle Freeze Frame (F0) immediately stores DTC plus information, Failure Record 1 (F1) (same information as freeze frame) immediately stores information, Failure Record 2 (F2) (same information as failure record 1) immediately stores information updates with every passed then failed ECM test, DTC becomes active. MIL illuminates after 5 seconds with the fault occuring (L81).
TYPE B - First fault during first ignition cycle - Freeze Frame (F0) immediately stores DTC plus information, Failure Record 1 (F1) (same information as freeze frame) immediately stores information and updates with every passed then failed ECM test, DTC becomes active. Second ignition cycle with same fault - MIL illuminates.
NON-EMISSION RELATED
TYPE C - First fault during first ignition cycle - Failure Record 1 (F0) immediately stores DTC plus information, Failure Record 2 (F1) (same information as failure record 1) immediately stores information and updates with every passed then failed ECM test. DTC becomes active. SERVICE telltale illuminates.
TYPE D - First fault during first ignition code - Failure Record 1 (F0) immediately stores DTC plus information, Failure Record 2 (F1) (same information as failure record 1) immediately stores information and updates with every passed then failed ECM test. DTC becomes active.
It is important to remember that the DTC as well as any stored failure record information will be erased if the vehicle battery has been disconnected or a clear DTC command is issued to the ECM. DTCs and failure record information will also be erased if 40 passes (only one pass per ignition cycle is counted) have been recorded without any faults. All emission (DTC type A or B) and non-emission (DTC type C and D) codes require this pass criteria.
FREEZE FRAME or any FAILURE RECORD will store the following:
^ Engine Run Time
^ Engine Speed
^ Vehicle Speed
^ Engine Load
^ ECT
^ IAT
^ MAP
^ MAF
^ TP Angle
^ APP Sensor 1
^ Loop Status Bank 1
^ Loop Status Bank 2
^ Short Term FT Bank 1
^ Short Term FT Bank 2
^ LT FT Bn. 1 Cruise/Accel
^ LT FT Bn. 2 Cruise/Accel
^ HO2S Bank 1 Sensor 1
^ HO2S Bank 1 Sensor 2
^ HO2S Bank 2 Sensor 1
^ HO2S Bank 2 Sensor 2
^ Injector Pulse Width
^ Fuel Level
^ Fuel Tank Pressure
^ Fuel Tank Press. Sensor
^ EGR Sensor
^ A/C High Side Pressure
^ Spark
^ Battery Voltage
^ Mileage since DTC clear