[F1 [F25.2. Treatment of secure messaging errors U.K.
[CSM_026] When the tachograph card recognises an SM error while interpreting a command, then the status bytes must be returned without SM. In accordance with ISO/IEC 7816-4, the following status bytes are defined to indicate SM errors:
′66 88′
:
verification of cryptographic checksum failed,
′69 87′
:
expected SM data objects missing,
′69 88′
:
SM data objects incorrect.
[CSM_027] When the tachograph card returns status bytes without SM DOs or with an erroneous SM DO, the session must be aborted by the VU.] ]