Code 83 relates to a GNSS (satellite positioning) signal fault. This means the tachograph is not receiving a valid GNSS signal, or it is unable to obtain position data.
GNSS is used by the tachograph to record location information, so if the signal is missing or interrupted, the unit may not be able to log position events correctly.
In most cases, Code 83 is not a complete tachograph failure, but it does indicate that the system cannot reliably detect a satellite signal.
Common causes include:
No GNSS signal being received (poor satellite coverage)
No position data available
Incorrect DTCO 4.1x configuration
Faulty GNSS antenna or related components
What to do if Code 83 appears:
Drivers should first check whether the vehicle is in an area with limited satellite reception (such as tunnels, underground parking, or dense urban areas). If the fault continues when the vehicle is back in open sky conditions, further checks may be required.
Recommended actions include:
Checking GNSS function
Checking and correcting DTCO 4.1x configuration if required
Replacing any defective components
If Code 83 remains active, the vehicle should be referred to an approved tachograph centre for diagnosis and repair, as GNSS faults may require inspection of the antenna, wiring, or internal tachograph system.
🔗 Find an approved tachograph centre:
https://www.gov.uk/find-approved-tachograph-centre-atc