Diagnostic Trouble Codes (DTCs)

WARNING: This page is about a different car, the 2002 Volvo C70, 2001 Volvo C70, 2000 Volvo C70, 1999 Volvo C70, and 1998 Volvo C70. However, it is still accessible from the selected car via links, so may be relevant.

When the control module detects a fault it stores the information in the form of a diagnostic trouble code (DTC) and the orange REC button indicator LED flashes once. Every time the ignition key is turned to position I or II the orange LED will flash once.

If the fault disappears (becomes intermittent) the diagnostic trouble code (DTC) is automatically erased from the control module. In principle the diagnostic trouble codes (DTCs) are erased in the operative cycle after the control module has registered that the diagnostic trouble code (DTC) has disappeared. Depending on what the diagnostic trouble code (DTC) was that was stored this can occur in different ways. If the indicator LED does not flash there are no DTCs stored and no read out is required.

Diagnostic trouble codes (DTCs) 2-3-1, 2-3-2, 2-3-5 and 2-3-6 detect the control signal function directly with ignition on. This means that the diagnostic trouble code (DTC) is erased the next time the ignition is turned on in the operating cycle after the cycle where the fault disappeared or was corrected.

For other diagnostic trouble codes (DTCs) the control module detects the signal/function first when the function is activated, as for example when a motor is activated, or self-adjustment is carried out. This means that diagnostic trouble code (DTC) is erased in the operating cycle after that during which the function was activated and registered as OK, in other words the second operating cycle.

Only when the diagnostic trouble code (DTC) is erased will the orange indicator LED stop flashing when the ignition is switched on.