Seat Tarraco electrical fault and navigation failure

A general electrical malfunction alongside a navigation system failure, especially with a stored error, does suggest a software-related issue could be at play. Given your Tarraco's mileage, a software bug seems plausible, though unusual. Have you tried any preliminary steps yourself, such as checking the battery voltage or looking for any obvious signs of water ingress near any of the control units? It's also worth checking all the fuses related to the affected systems before assuming the worst. Did the error code point to a specific module or a more generic system fault?

Battery voltage is fine and I couldn't find any water damage. Fuses all look good too. The error code wasn't specific, just something about 'control unit programming implausible'. Could a simple software reset potentially fix it, or is it more serious than that?

Given the 'control unit programming implausible' error, and the fact that basic checks haven't revealed any hardware issues, it does strengthen the argument for a software problem. While a software reset might resolve the issue, the implausibility suggests a deeper problem than a simple glitch. Recalibration could be a solution. It would be prudent to consult with a workshop that has expertise in your vehicle's specific software version.

The dealer did a software reset and recalibration. It cost me 240€, but everything seems to be working fine now. Thanks for confirming my suspicions!