Diagnostic trouble codes (DTCs)
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2006 Volvo S80, 2005 Volvo S80, 2004 Volvo S80, 2003 Volvo S80, and 2002 Volvo S80. However, it is still accessible from the selected car via links, so may be relevant.
Diagnostic trouble codes (DTCs) are stored in the control module if the climate control module (CCM) detects a fault. Every diagnostic trouble code (DTC) has a counter which records the number of cycles which have been "fault-free" since the diagnostic trouble code (DTC) was stored. A fault which is detected in each operating cycle is defined as permanent. A fault which is detected in one or more operating cycles (although not the present one) is defined as intermittent.
An operating cycle is the period from when the ignition was switched on, remained on for at least 10 seconds and was finally switched off for at least 10 seconds.