Nec B58944 Datasheet | Free Upd

The is a specialized automotive integrated circuit, frequently used as a memory chip in Bosch Engine Control Units (ECUs) . It is functionally equivalent to the μPD43256BGU-70L , a 256 Kbit CMOS static RAM.

Parts are sometimes available via specialist electronics brokers like Jotrin Electronics Ecufixtool

Based on internal structure and common search patterns, the is most likely one of two things:

This site specializes in obsolete components. If NEC stopped making the B58944 in 1995, this is your best bet.

Ensuring correct orientation and soldering during the replacement of a damaged IC.