error code 26 control-unit supply b+
 

my vehicle has this error 26 control-unit supply b+. cna anyone give advice as what to look at? we have check the battery supply, ground cables of wiring harness to body, engine to body, alternator and starter connection and everything seems to be ok. is there anything that i am missing? this error came out when we swapped our engine froma 4 cyl. to a 6cyl engine. we repplaced the engine, tranny, harness and dme.

hope someone can give us some light on our situation.

what kind of car???

its a 1995 e36 316. the engiine we placed was a 1995 S50 US version 3L M3.