Malfunction Records

NOTE: A fault mentioned below is an error Flag set in the PCM indicating a diagnostic test has run and failed. The Fault is designated by a DTC in malfunction history records, but does not suggest that the DTC is active.

The Scan tool displays vehicle malfunction history information located in the Diagnostic Trouble Code menu under the subheading Freeze Frame / Failure records. Freeze Frame / Failure records contain a maximum of 7 records; 1 FREEZE FRAME plus 6 FAILURE RECORDS.

Government regulations mandate that all emission related faults store freeze frame data, designated as failure record "0" on Scan tool, at time of the first failed test. 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 faults. All other emission related faults that set will not be stored in freeze frame unless the initial fault is cleared.

Failure records 1 through 6 on Scan tool store information at time of first fault and are updated every time the ECM runs a test and fails the diagnostic. If another fault were to occur, the DTC in record 1 would be moved to record 2 and the new DTC would be placed in record 1 (First in, first out). If a new failure is detected while all failure records are full, the number 6 record will be erased (oldest) and newest fault will be updated to failure record 1.

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 "0" stores DTC plus information, Failure Record 1 stores same record as freeze frame "0" and updates with every failed test, DTC becomes active, MIL illuminates.

Type B - First fault during first ignition cycle - Freeze Frame "0" stores DTC plus information, Failure Record 1 stores same record as freeze frame and updates with every failed test.

Second ignition cycle with same fault - Failure Record 1 updates, DTC becomes active, MIL illuminates.

NON-EMISSION RELATED
Type C - First fault during first ignition cycle - Failure Record 1 stores DTC plus information and updates with every failed test, DTC becomes active, Service Telltale Lamp Illuminates.

Type D - First fault during first ignition cycle - Failure Record 1 stores DTC plus information and updates with every failed test, DTC becomes active.

FREEZE FRAME 0 will store the following:
^ DTC#
^ Fuel System Status
^ Calculated Load Value
^ Engine Coolant Temperature
^ Short Term Fuel Trim - Bank 1
^ Long Term Fuel Trim - Bank 1
^ Short Term Fuel Trim - Bank 2
^ Long Term Fuel Trim - Bank 2
^ Intake Manifold Absolute Pressure
^ Engine RPM
^ Vehicle Speed

Failure records 1-6 will save the above information as well as:
^ Intake Air Temperature
^ Mass Air Flow
^ Throttle Position Angle
^ Pedal Position (Sensor #1)
^ Battery Voltage
^ Meters since last code clear
^ Average Injector Base Pulse Width
^ Ignition Timing Advance #1 Cylinder
^ Heated Air/Fuel Sensor Bank 1 Sensor I
^ Heated Air/Fuel Sensor Bank 2 Sensor 1
^ O2 Sensor Volts - Bank 1 Sensor 2
^ O2 Sensor Volts - Bank 2 Sensor 2
^ Fuel Level
^ A/C Pressure
^ EGR Feedback
^ Fuel Tank Vacuum Pressure
^ Engine Run Time

Failure records for the ECM will record all of this information failure record data will be erased from ECM memory during a code clear or after 40 warm-up cycles without any faults detected.