The 2000 Buick LeSabre’s fuel pump relay can be found under the rear passenger-side in the bussed electrical center (BEC), and is labeled as mini relay #39.
The fuel pump relay in your 2000 Buick LeSabre powers the fuel pump, which then pumps gas into your engine for combustion. The fuel pump relay is controlled by the LeSabre’s ignition/powertrain control module (PCM). When a fuel pump relay stops working, gasoline won’t get to your engine, which will make driving difficult—if not impossible.
Luckily, fixing a broken fuel pump relay is relatively inexpensive. Take your LeSabre to a qualified, trusted mechanic, who will be able to replace the part for around $25. You’ll likely have to pay for an hour or so of labor, but resolving this issue is pretty easy.