Testing Notes

NOTE: Intermittent concerns are the most difficult concerns to diagnose. Different techniques are required to resolve these issues without wasting repair time or replacing good components.

Three procedures are used to identify an intermittent condition as soon as possible so that efforts may be directed accordingly. These are:
1. Determining repeatability of DTC at the beginning of each pinpoint test. This step helps separate repeatable conditions from intermittent conditions at the start of diagnosis and results in the elimination of several unnecessary procedures. It also helps focus the technician's attention to the most likely issue at hand.
2. Drive tests over specific conditions aimed at intermittent failures in components and wiring. Solder joints, loose connections, and weak terminations are the most common sources of intermittent operation in components and wiring. Driving raises operating temperatures of components and vibrates both the wiring and the components. It also allows the technician to perform certain maneuvers which are more likely to cause the concern to repeat and locate the source of the concern.
3. Wiggle tests aimed at intermittent wiring concerns. This test is directly aimed at damaged terminations and loose terminals within connectors at circuit endpoints. It is not likely to detect an open or shorted condition of a circuit between two connectors.