Button kit
â–¶ How to fix
Locate the button which is causing the problem and check that it is not jammed in the depressed position. Attempt to reset the function. If the fault cannot be rectified or if it recurs, the tachograph must be renewed.
What you'll see
No driver-visible symptom recorded.
System reaction
No system-reaction text recorded.
Diagnostic depth
Detection
The tachograph button kit has given a constant signal.
Possible cause
One of the buttons in the button kit has been depressed too long or is constantly depressed.