Code 12 indicates that a communication fault has occurred while downloading data from a driver card or the vehicle unit (VU).
In simple terms, the tachograph and the download equipment were unable to communicate properly during the download process.
What this means for Transport Managers and Operators:
This code commonly appears during routine card or vehicle downloads. It does not automatically mean the tachograph is faulty, but it does mean the download was unsuccessful and must be repeated to remain compliant.
You should:
• Repeat the download process
• Check the connection cable for loose fitting or visible damage
• Try a different download lead or download device if available
If the issue continues:
Further checks of the tachograph download interface or internal components should only be carried out by an approved tachograph centre.
🔗 Find an approved tachograph centre (ATC):
https://www.gov.uk/find-approved-tachograph-centre-atc
Consistent download failures can put your compliance at risk, so always act promptly and escalate to an ATC if basic checks do not resolve the issue.