Case of recording unit opened
â–¶ How to fix
* Check the sealing (housing) of the tachograph. * If the error message appears repetitively, replace the tachograph.
What you'll see
No driver-visible symptom recorded.
System reaction
MC26/EV401: * Warning message with error text "security breach" together with Memory Code 26 is shown in the tachograph display. * The warning message will be displayed repetitively every hour until the cause is withdrawn. * Event stored in the tachograph memory * Event stored and in the inserted tachograph card. * System event in TCO1 CAN message is set to active. * Tachograph warning (amber T) is displayed in the instrument cluster.
Diagnostic depth
Detection
The tachograph housing was or is opened.
Possible cause
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