Circuit Description
WARNING: This page is about a different car, the 2000 Pontiac Firebird, 2000 Chevrolet Corvette, and 2000 Chevrolet Camaro. However, it is still accessible from the selected car via links, so may be relevant.
PCM uses a common 5-volt reference circuit as a sensor feed to left tank fuel level sensors. PCM monitors voltage on 5-volt reference circuit. If voltage is out of range, DTC will set.