Cruise Control: Description and Operation

Overview

General

The control module has a built-in diagnostics system (Volvo on-board diagnostic (OBD) system), which monitors input and output signals continuously. Information about system performance can be obtained using the Volvo Scan Tool (ST) connected to the data link connector (DLC).

Diagnostic trouble codes (DTCs)

When a fault occurs it is stored in the control module as a diagnostic trouble code (DTC) provided that road speed has been above 35 km/h for at least 15 seconds.

Diagnostic trouble codes (DTCs) can be stored in the control module memory only as long as the ignition is on. When the ignition is switched off these diagnostic trouble codes (DTCs) are erased. The control module will detect diagnostic trouble codes (DTCs) again when vehicle speed has been above 35 km/h for at least 15 seconds.

Miscellaneous

The control module also stores a code indicating the most recent cause of cruise control disengagement. This code is stored in control module memory only as long as the ignition is on.