Diagnostic Aids

Using FREEZE FRAME and/or FAILURE RECORDS data mode may aid in locating an intermittent condition. If DTC cannot be duplicated, information included in the FREEZE FRAME and/or FAILURE RECORDS data can be useful in determining how many miles since the DTC set. The FAIL COUNTER and PASS COUNTER can also be used to determine how many ignition cycles the diagnostic reported a pass or a fail condition. To isolate when DTC failed, operate vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.).

Fig 1: DTC P1641 Schematic - Fleetwood

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC P1641 Schematic - Except Fleetwood

Courtesy of GENERAL MOTORS CORP.