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DME 405 IAT value map

Posted: Sun May 21, 2023 2:58 am
by Skeoph
Hi,
My MAF is dead on my M50b25 nv and a new one cost around 650€.. so i'm planning to swap it for a M54 MAF that is 55€.
My problem is, it's a 6 Pins MAF with air temperature sensor, so i need to change this value too in my file for the M54 ones.
I have the MAF adress map but not the IAT one.. if someone have it ?

Or maybe if someone have an alpha'n table tunned for stock M50b25 ? cause base alpha'n is very small and not for all RPM range..

Thanks

Re: DME 405 IAT value map

Posted: Sat Jun 17, 2023 12:06 pm
by olafu
Header starts at 0x6F00, table starts at 0x6F0D. Problem is it's shared for coolant temperature sensor and air temperature sensor. Tables are identical between vanos engine and non vanos engine.
I think M50B25NV has no air temperature sensor in MAF. Air temp sensor is located under intake manifold like vanos engines.
NV engine has older "hot wire" type MAF. It needs regular cleaning and it's done by glowing the metering wire. These extra wires coming to MAF are for cleaning function. If i remember, DME cleans metering wire once of ten power off cycles.

---- EDIT ----
According some other information, DME cleans metering wire in every power off cycles.

Re: DME 405 IAT value map

Posted: Fri Oct 18, 2024 12:21 am
by alicent23
To replace your M50B25 MAF with an M54 unit, you'll need to adjust the IAT mapping in your tuning files; unfortunately, specific IAT address maps for the M54 aren't widely available, so community forums like e34.net or e30tech.com may be helpful.

Re: DME 405 IAT value map

Posted: Wed Mar 12, 2025 1:52 pm
by Baltica
Buy a Chinese maf from Steelox. It works great, the car flies like an airplane)