What it means: a card fault, the tachograph isn't reading your driver card properly.
Try first: remove the card, check it, reinsert it.
Can you keep driving: yes, but log manually while the fault persists.
What fault 41 means
Fault 41 is a card fault. Unlike fault 40, which points at the tachograph unit itself, this one specifically means the connection between your driver card and the card reader isn't working correctly.
What you can try yourself
Before treating this as an equipment breakdown, check the obvious: remove the driver card, look at the chip for dirt or scratches, and reinsert it firmly. A dirty contact or a card inserted at an angle causes exactly this fault, and it often clears without a workshop visit. If it doesn't clear, treat it as a genuine malfunction under the same rules as fault 40.
The difference with 40
Fault 40 is a general equipment fault, independent of any card. Fault 41 is specific to the card connection. The distinction matters for diagnosis, but not for your obligations: both fall under the same article of the regulation.
Can you keep driving
In the event of the breakdown or faulty operation of a tachograph, the transport undertaking shall have it repaired by an approved fitter or workshop, as soon as circumstances permit. If the vehicle is unable to return to the transport undertaking's premises within a period of one week calculated from the day of the breakdown or of the discovery of defective operation, the repair shall be carried out en route.
Regulation (EU) No 165/2014, Article 37(1). Accessed 26 August 2026.
What to log right away
While the tachograph is unserviceable or malfunctioning, the driver shall mark data enabling him to be identified (name, driver card or driving licence number), including a signature, as well as the information for the various periods of time which are no longer recorded or printed out correctly by the tachograph: (a) on the record sheet or sheets, or (b) on a temporary sheet to be attached to the record sheet or to be kept together with the driver card.
Regulation (EU) No 165/2014, Article 37(2).
If reinserting the card doesn't clear the fault, start the manual record immediately: your name, driver card or licence number, a signature, and your driving and rest times from the moment the fault appeared.
Who has to fix it, and by when
If the card itself is damaged rather than the reader, the repair obligation shifts: a damaged driver card needs replacing, not the tachograph unit. If it's the reader that's at fault, the same repair deadline applies as for fault 40, before the vehicle returns to base, or within one week if it can't.
What it costs
A dirty contact costs nothing to fix yourself. A genuine reader fault or a damaged card is a workshop or replacement cost, which the regulation doesn't set a price for. Keep your manual record until the fault is resolved and logged.
Also read
Sources
- Regulation (EU) No 165/2014 on tachographs in road transport, Article 37, consolidated version. EUR-Lex
Legal text quoted verbatim from the consolidated English version published on EUR-Lex, accessed 26 August 2026. VDO does not publish an official fault-code glossary in English; the plain-language description above is our own, the legal citation is not.
Stuck? See where there is still room.
Drivers report what they see themselves. Parking full, traffic, hazard, roadworks. Open the app and stop driving alone.