On-Board Diagnostic Tests

A diagnostic test is a series of steps which has a beginning and an end. The result of which is a pass or fail reported to the Diagnostic Executive. When a diagnostic test reports a pass result, the Diagnostic Executive records the following data:
- The diagnostic test has completed since the last ignition cycle.
- The diagnostic test has passed during the current ignition cycle.
- The fault identified by the diagnostic test is not currently active.

When a diagnostic test reports a fail result, the Diagnostic Executive records the following data:
- The diagnostic test has completed since the last ignition.
- The fault identified by the diagnostic test is currently active.
- The fault has been active during this ignition cycle. The operating conditions at the time of the failure.