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.
If the control module detects a fault, it stores a diagnostic trouble code. A fault detected during the most recent operating cycle is defined as permanent. Other faults are defined as intermittent. If a fault should disappear after a permanent diagnostic trouble code is stored in the control module, the control module retains information on the fault.