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The theory & operation of the oil pressure & fuel level circuits differs from the previous two circuits in only one way [in my car]: both senders are transducers, which means they directly output a voltage, 0-5V specifically. For oil pressure, the GM ECU documentation provides a formula for oil pressure vs voltage: V = (PSI+16)/32. For fuel level, I opted for a capacitive sender where 1V = empty and 5V = full. Because the output on both senders is a voltage, the sender doesn't need a voltage divider, which is why you don't see the pull-down resistor on the input of these senders.

I put the oil pressure formula into Excel and calculated the resulting voltage at various PSI levels, then picked the limits for both the bar graph & High & Low thresholds, and calculated the resistors just like before.




For the Fuel Level, as I said, it's nearly the same. There is no high threshold; only a low threshold is required. Other than that, the resistor values are different for both the LM2903 & LM3914.