If you have the component and cannot find a datasheet:

Q: What is the collector-emitter voltage rating of the NEC B58944? A: The collector-emitter voltage rating of the NEC B58944 is 80V.

From service records and component-level repair logs (2020–2021), the NEC B58944 has been found in:

Search for 2SB589 or B589 transistor instead.

If a real 2021 NEC datasheet for B58944 existed, it would include:

The NEC B58944 is a type of NPN Silicon Transistor. Here are some general specs and characteristics that might be helpful:

If you are performing a repair, ensure you are referencing the specific variant if your board uses the combined NEC/BOSCH chip architecture. If you'd like, let me know: The specific vehicle or ECU model you are working on. The fault symptoms (e.g., no start, specific error codes).