If the engineers who did the ECU had half a brain put together they would have covered that very early in the design phase. It should be fine, have you tried it?
Mats Strandberg -Scuderia Rosso- Now burned to the ground... -onemanracing.com- -Strandberg.photography-
GTV 2000 -77 - Died in the fire.
155 V6 Sport -96 - Sold!
Mats should be right, one diode on the power supply would protect against that. Bosch hopefully would have done it as there is a high probability of a reversed battery happening in any car. But, life's not like that.
Just a point to be careful about - the positive battery cable in my car has a green sheath. As an Electrical Engineer green to me means earth, which often means negative. Every time I go to the battery I fall for it. I have been meaning to put some red heatshrink over the positive cable for months.