Now you’ve wired your MAP sensor as per my guide, it’s time to check it’s plumbed in properly and reading what it should. To check the reading we require a 3rd party tool called Testo. Testo is based the Ediabas API and provides realtime data.
In order to use Testo you will need the following:
- A copy of Testo, available to download here
- Working INPA installation
- An OBD2 cable that is compatible with INPA
- Visual Studio C++ redistributable package, this is only required if you receive an error regarding ‘MSVCP100.dll’.
- Extract Testo to a folder and run the ‘Testo.exe’ executable.
- Select ‘File’ and then ‘Detect ECU’. A new window will appear, press the ‘Detect’ button.
- MSS52/MSS54/MSS54HP fuer S54B32 will be highlighted in the ECU list. Scroll down once more and select ‘MSS54 (SERIAL).
- Double click ‘Vanos’ under ‘Jobs’.
- A new window will be launched. Resize the table headings so you can read the values correctly and ensure that ‘MAP pressure’ and ‘MAP pressure voltage’ is ticked.
With the engine off and the key at position 2 the MAP sensor should read atmospheric pressure, this will obviously vary depending on your altitude etc but should sit around 1000mbar / 4.9-5v.
With the engine running there will be vacuum and the value should be around 200-300mbar / 1-1.1V. This will obvious vary depending on idle speed.
If your results vary, please re-check your wiring and re-check the vacuum to your MAP sensor.