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Home >> Volvo >> 2003 >> S40 L4-1.9L Turbo VIN 29 B4204T3 >> Repair and Diagnosis >> Cruise Control >> Description and Operation >> Diagnostic Functions >> Overview
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Diagnostic Functions: Overview






Overview

General




The control module continuously monitors in and out signals using its own integral diagnostics, the Volvo On Board Diagnostic system. Information on system performance can be read off 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 DTC (Diagnostic Trouble Code) provided the car's road speed is over 35 km/h (22 mph) for at least 15 seconds.
The DTCs can be stored in the control module's memory only if the ignition is turned on. When the ignition is switched off these diagnostic trouble codes (DTCs) are erased. For the control module to detect DTCs again the car's road speed must be over 35 km/h (22 mph) for at least 15 seconds.

Miscellaneous
The control module will also store a code which indicates the most recent cause for cruise control disengagement. The code can be stored in the control module's memory only as long as the ignition is turned on.

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