Diagnostic Aids

Use the Freeze Frame and/or Failure Records data in order to locate an intermittent condition. If you cannot duplicate the DTC, the information included in the Freeze Frame and/or Failure Records data may aid in determining the number of miles since the DTC set. The Fail Counter and Pass Counter can also aid in determining the number of ignition cycles that the diagnostic reported a pass and/or fail. Operate the vehicle within the same freeze frame conditions (RPM, load, vehicle speed, temperature, etc.). This will isolate when the DTC failed.
Refer to TESTING FOR INTERMITTENT AND POOR CONNECTIONS in Wiring Systems.

Fig 1: DTC P1663 Diagnostic Table (1 Of 2)
Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC P1663 Diagnostic Table (2 Of 2)

Courtesy of GENERAL MOTORS CORP.