Where is the oil sensing unit on a 2007 Chevy silverado with 5.3 liter engine?

The oil level sensor on a 2007 Chevy Silverado 5.3L is not a separate, easily identifiable unit like an oil pressure sensor. Instead, the oil level is detected indirectly by the PCM (Powertrain Control Module) using various inputs, primarily from the oil pressure sensor. There isn't a dedicated "oil sensing unit" for level in the traditional sense.

The oil pressure sensor itself is located on the engine block, near the oil filter. Its reading helps the PCM estimate oil level, although not directly. Low oil pressure is often an *indication* of low oil level, but not a direct measurement.

If you're having issues with oil level readings, you'll likely need to consult a repair manual or a mechanic to diagnose the problem. It could be a faulty oil pressure sensor, a wiring issue, or a problem within the PCM itself.