Diagnostic Trouble Codes (DTCS)
WARNING: This page is about a different car, the 2010 Volvo V70, 2009 Volvo V70, and 2008 Volvo V70. However, it is still accessible from the selected car via links, so may be relevant.
A diagnostic trouble code (DTC) is stored if the control module detects a fault. A fault which is detected in the most recent operating cycle is defined as permanent. Other faults which are detected are defined as intermittent.
If for some reason a fault disappears after being stored in the control module as a permanent diagnostic trouble code, the information remains stored in the control module. If a fault is no longer permanent, the diagnostic trouble code remains as intermittent.