Hard Failures

On Fox, the Digifant I electronic control unit used in California vehicles is equipped with a permanent fault memory. If a fault occurs in monitored sensors and components, they store a fault in memory.

If malfunctions are present for more than 5 seconds, they are stored as Diagnostic Trouble Codes (DTCs) and will be displayed as a permanent malfunction even though the malfunction is not occurring at the time DTCs are displayed. Malfunctions that affect oxygen sensor control can only be read accurately after a test drive of at least 5 minutes.