You can figure this answer out by noting the values with engine off and with engine on.

With engine off you should have about ~1000 kpa mbar ( 1 bar =atmospheric pressure).
If the sensor is reading zero with the engine off, then the diesel engine only works under boost, meaning atmospheric pressure + x.

That would be pressure relative to atmospheric.
I'm leaning to this as there should definitely not enough vacuum in a modern diesel intake to produce the numbers you were seeing.

Ok makes sense. Will have a look.

The values that are read by MES are absolute, i.e. 1,5 bar is actually 0,5 bar higher than atmospheric pressure (1 bar).
Attache is what I read from my 1.3mjt...

BRs, Bernie

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