VCDS, Charge air pressure, specified vs. Actual

[sannouni]

At idle, normal operating temperature, I'm getting charge air pressure reading of 320hpa specified vs. 1055hpa actual.
Is that normal ?

I'm hunting down a cold start misfire, I've been playing around with VCDS engine measuring values, and came across this finding.

[A4x]

Yes normal. The actual reading includes atmospheric pressure.

[JLAllroad]

Take the same reading ignition on without the car running and you will get the atmospheric value for your altitude.


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[sannouni]

Thank you for the quick responses

[bb-tt]

Take the same reading ignition on without the car running and you will get the atmospheric value for your altitude.


Sent from my iPhone using Audizine

Or you can include ambient pressure in your log (see example below). I usually record and save before i start logging then remove the "ENG106228 Ambient air pressure" parameter and start logging.

Address 01: Engine (8K2 907 115 AG)

14:58:32
IDE00021 Engine speed 946 /min
IDE00083 Throttle valve position (absolute) 12.5 %
IDE00190 Charge air pressure specified value 320 hPa
IDE00191 Charge air pressure: actual value 994.84 hPa
IDE00347 Air mass: actual value: 3.22 g/s
IDE00559 Current of oxygen sensor bank 1 sensor 1 (broadband sensor) 1.000 Lambda / -0.016 mA
IDE00593 Ignition timing adjustment cylinder 1 0.0 Degrees
IDE01900 Charge press. ctrl.: spec. value 1.6 %
ENG106228 Ambient air pressure 987 hPa