What is the component in the PCB photo labeled S4?

Question

Electronics

Good day!
It is necessary to determine what kind of component is on the printed circuit board. Marking on the case S4, the type of case is unknown to me. The housing has 5 pins visually visible: two on one side and one on each of the remaining sides. Help identify this component.
Additional information: the circled red component on the left of the photo - the left terminal and the lower one are called by the tester, the upper one is not connected to them, however, its lack of ringing may be due to varnish coating or there simply was no contact with the probe (it is difficult to crawl), the ZXMP6A17E6 transistor is located next to the right in the SOT-26 package - on the right, the upper output of the component of interest is connected to the source of the transistor, the track of the lower output goes down to the resistor and further in an indefinite direction.
A photo of the case below (the component of interest is marked with a red circle):

Answer 1

After cleaning the board from debris and dissolving the varnish, the possibilities for analysis increased. Studying the strapping, I managed to establish that I was dealing with a pnp transistor. True, at first this was an assumption, but later everything was confirmed: the knowledge that this transistor helped in determining the case unknown to me - it turned out that an extremely rare beast was before my eyes - MLP322 2x2 mm. Based on this and thanks to the almighty Google, I finally identified the component - this is the ZXT4M322 from Diodes Incorporated. Thanks to all!
For those who are interested, here is a link to the ZXT4M322 specification

Answer 2

www.s-manuals.com/ru/smd/s4
ecworld.ru/support/sdd/s4.htm
caxapa.ru/codebook/?search=S4
and so on and so forth...