MSB map switching

Posted: 
Wednesday, April 17, 2019 - 07:00

I was having a look at the MSB diagnostics a couple of days ago and came across the request for switching between maps.
Some MSB ECU's - most often the Auto versions - come with tunes former than one market and the switching function provides a method for selecting the correct tune.

NOSELECT "Tune"

The NOSELECT tune is default on a new spare ECU. The tune provides just enough functionality to start an engine.
The duration maps are 2 x 2 tables that have rows for 0 and 750 rpm, so should allow the engine to idle.

The remaining tunes are full market specific fuel maps.
In this case the ECU is an MSB1011191 and has tunes for European and Japanese Auto D2s.

European Auto Tune

Japanese Auto Tune

With some minor modifications to the .bin this ECU should support at least one additional fuel map.
The NOSELECT "tune" seems to be referenced in several places during startup so possibly needs to be retained as is.

Even so this opens up the possibility of software switching between two or three maps without resorting to additional hardware to perform address line switching hacks.