Diagnostic Trouble Codes
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2009 Volvo S60, 2008 Volvo S60, 2007 Volvo S60, 2006 Volvo S60, and 2005 Volvo S60. However, it is still accessible from the selected car via links, so may be relevant.
If the control unit detects an error, it stores a diagnostic trouble code. There are 36 diagnostic trouble codes in total. An error that was detected the last time the engine was running is defined as permanent. Other detected errors are defined as intermittent.