So we are going to remap 8D0 907 401 H ecu. This ecu are used in infamous 2.5 tdi v6 audi engines. These engines comes with VP44 fuel distributor pump who often goes bad. This ecu are late MSA15 . As i tuner i can say that this engine and its software was made in big hurry. Basically Audi needed to design new TDI engine with less emissions, more friendly to nature to replace old 2.5 I5. VP44 pump was fitted cause commonrail was still in development and it did not felt like it was ready to come out. Pump offers nice injection pressure.
Also ecu software as i said seems like unfinished. Like final tunes were not made. But atleast we can do it now. Pump are limited to around 50-55mg. Pump voltage calibration map are located in pump itself and not in ecu like it usually are. Safe boost for turbo are 1.3-1.4 bar. Can do that boost really stable and for long time. So i have located basic maps and done basic remap. It have been tested and car runs ok. Be sure that cars Mass Air Flow sensor are working good(850mg/hub air at full load). Otherwise i would advice to do mafless tune. I will write about mafless tune later.
Things we need to do basic remap for this ecu :
- Drivers wish map. This map basically converts accelerator pedal % to IQ (injection quantity in mg). % vs rpm = IQ.
- Torque limiter. This map limits your engine torque at various rpms and atmosphere pressure. rpm vs atm. pressure = IQ
- Smoke limiter. Takes readings from MAF sensor and depending from rpm transfers it to iq.
- SOI(start of injection) maps. These maps advance or retard pump timing depending on rpm and iq. rpm vs iq = SOI . There are also SOI limiter by temperature.
- Boost maps. There are basically 2 maps. Boost target( IQ vs rpm = mbar (boost) ) and boost limit ( atm pressure (mbar) vs rpm = mbar (boost) ).
As you might saw there are no SVBL. There might be one value that i think are SVBL, but its really not working in this ecu. As i said this ecu seems to be made in hurry. All you need to do is edit boost target and limit map. You are ready to go.
Attached file list : Ori file, WinOls map pack, tuned ori file, seperated and checksumed hi and low files ready to put in ecu.
Here are .rar file : A4 2.5tdi 8D0907401H remap
8D0 907 401H Map addresses :
- 05024 Boost target
- 053D2 Boost limit by atmosphere pressure
- 01AFA Drivers wish
- 03E44 Torque limiter
- 04228 Smoke limiter(MAF)
- 05C3A Soi limiter by temperature
- 05D2A SOI target