2002 Buick Lesabre FUEL LIGHT

Engine Mechanical problem
1999 Buick Lesabre 6 cyl Two Wheel Drive Automatic 180000 miles
No it is unlikely to be the pump itself but is the fuel level sensor. They are in the same assembly that is inserted into the tank from above.
MyEXPEREINCE: I have had this happen twice: on a 1999 LeSabre and on a 2001 Regal. The Fuel level indicator was pegged at Full, regardless of actual level. The level sensor is a float with an arm that rubs some very delicate, flat copper contacts. They were corroded ever so slighly. On the 2001 Lesabre I was able to easily remove the sensor/pump assemply through a access pannel in the trunk- without removing the tank. I lightly shinned the very delicate contacts to make it work. DO THIS: 1111-Check the fuse is OK. It it is OK then 2222- confirm the sensor is the problem without removing anything, - find the purple wire going to the sensor under the access pannel in the trunk. The pannel is a silver one about 6 inchesd square. This wire is in the bundle going to the sensor from the front of the car. Ground this purple wire (the side towards the front of the car), start the car. If the sensor is the problem, then the fuel guage will read Empty. If iit reads Empty then 3333 the sensor is not working. Your alternatives include replacing the whole pump/ sensor assemply (easy), replace only the sensor, or try shining the delicate flat contacts on the sensor like iI did. (They are easy to spot and their is nothing to lose). A new pump/sensor assembly costs 130$ and is easy to replace. If you remove the assemply. ALWAYS disconnet the battery and be careful igniting any spilled gas.