Currently driving a 58 plate Actros with the above digi tach in it, however the clock is 4 minutes slow.
Now I’m aware that you can alter the time, but it’s only by +/- 30 minute blocks, and the fact it’s slow is bugging the hell out of me.
Had a look online and I can only confirm what I know about the +/- scenario.
Surely there must be a way to have an accurate time reading?
Ken.
I am sure you can only correct it by 1 minute per week so 4 minutes out will take 4 weeks i will dig out the manule and get back to you on this.
you can change the UTC by one minute per week in the menu so it will be ok in four weeks time 
When you say “the clock” presumably you mean the UTC time that’s recorded on the driver card and VU not the local time which is shown on the display.
The UTC time can be changed by 1 minute per week but the local time which is on the unit display can be corrected to whatever you want it to show.
Quinny:
Currently driving a 58 plate Actros with the above digi tach in it, however the clock is 4 minutes slow.Now I’m aware that you can alter the time, but it’s only by +/- 30 minute blocks, and the fact it’s slow is bugging the hell out of me.
Had a look online and I can only confirm what I know about the +/- scenario.
Surely there must be a way to have an accurate time reading?
Ken.
The 30 minute blocks you mention is for altering the displayed time. To correct UTC time you can, as already mentioned, only do it by 1 minute a week, unless you take it to the workshop. They can correct the 4 minutes for you.