Reading and Clearing Diagnostic Trouble Codes

Reading off Volvo on-board diagnostic (OBD) system

General




Information about faults and other information can be read off using the Volvo Scan Tool (ST) connected to the data link connector (DLC). Connecting the Volvo Scan Tool (ST) is described in.
The Volvo Scan Tool (ST) communicates with the cruise control using a standard communications interface.
The data link connector (DLC) is located on the left of the center console under the dashboard.

The Volvo Scan Tool (ST) can be used to:
- Read and erase the diagnostic trouble codes (DTCs).
- Check input signals to the control module.
- Read out the last reason that the cruise control was disengaged.

Activating Volvo on-board diagnostic (OBD) system:
- Ignition ON
- normal battery voltage.

Reading and erasing diagnostic trouble codes (DTCs)
Used for reading out and erasing DTCs stored in the control module.
The OBD system can identify four types of fault and assign diagnostic trouble codes (DTC) to them.
Connect Volvo Scan Tool (ST). See.

Hint:
The diagnostics on the cruise control system differ from many of the other diagnostic system functions in that the DTCs are only stored until the engine is turned off. So it is important not to turn off the ignition after a test drive until any DTCs that have been stored have been read off using the Scan Tool (ST).
Another difference is that the control module must receive a vehicle speed signal (VSS) above 35 km/h (22 mph) for at least 15 seconds before it will store any DTCs.

Note! If the engine is turned off after a test drive the DTC 1-1-2 will always be stored when the ignition is turned on. The test drive must then be carried out again.

Erase diagnostic trouble codes (DTC)
- by turning the engine off
- by using the Scan Tool after the DTCs have been read.