Reading Off Volvo on-Board Diagnostic (OBD) System

Reading off Volvo on-board diagnostic (OBD) system

General





Using the Volvo Scan Tool (ST) it is possible to:
- Read off and erase diagnostic trouble codes (DTCs) stored.
- Check input signals to the control module.
- Read off the cause of the last cruise control disengagement.

Activating the Volvo on-board diagnostic (OBD) system:
- ignition on
- normal battery voltage.

Reading and erasing diagnostic trouble codes (DTCs)
Used for reading off and erasing diagnostic trouble code (DTC)s stored in the control module.
The on-board diagnostic (OBD) system can identify four types of fault in the form of diagnostic trouble codes (DTCs).
For a list of diagnostic trouble codes (DTCs) and fault-tracing, see Response and Diagnostic Trouble Code (DTC) tables Response and Diagnostic Trouble Code (DTC) tables.

Hint:
The cruise control on-board diagnostic (OBD) system differs from most other systems' diagnostic functions in that diagnostic trouble codes (DTCs) are only stored in the control module until the engine is turned off. So it is important not to switch off the ignition after a test drive until any diagnostic trouble codes (DTCs) that have been stored have been read off.
Another difference is that the control module must receive a vehicle speed signal (VSS) above 35 km/h for at least 15 seconds before it will store diagnostic trouble codes (DTCs).

Note! Diagnostic trouble code (DTC) 1-1-2 will always be stored if the engine is turned off after a test drive. The test drive must then be carried out again.

Erasing diagnostic trouble codes (DTCs):
- by turning the engine off
- using the Volvo Scan Tool (ST) when the diagnostic trouble code (DTC) has been read off at least once.