This board is a transmission control module from a mercedes van which I have been told by a garage needs to be replaced because of a "short". For the cost of the part, it's worth taking a look at it to see if the fix may be easy, but I can't identify a few components on the board.
Firstly, are a number of these small surface mount boxes which are a light grey color. I have tried a number of multimeter tests on them. They do provide 0.5nF capacitance, so does that mean its a capacitor?
Above is a component labeled "934 U1D." (branding looks to say "ON"). I can find no information about this component online. There are several of these components on the board, and the only measurement I can get is a resistance reading, which for some of these parts is 214 Kohm, and for others only 2Mohm, but I think this variance is just due to the fact that I was measuring them in circuit. What is this component?
Lastly, there are 9 of these transistors. I tested them all thoroughly to the best of my ability using my multimeter's diode test mode. All displayed the same readings for all tests (I tried every combination of probe positions on every leg), except for one test on ONE transistor alone, which when placing one probe on the large "heatsink" part (sorry I don't know what to call it. the metal leg which runs the length of the component at the top) and the other on the bottom left leg, it displayed a voltage drop of 1.9V, where the rest of the transistors for the same test had displayed an open circuit. Could this be an indication of a faulty transistor, or might this be a problem with testing these components in circuit?
How is one meant to identify components like these when they are not labeled on the board, and or, there is seemingly no datasheets online?