2005 Chevy Malibu Check Engine Light/Fuel Indicater (Dash)

Here is a bulletin for this concern. Fuel Gauge Not Reading Full After a Customer Fill - keywords cap card cluster gas inaccurate inoperative IPC IP light low message P0455 resistor sensor SES tank - (Apr 10, 2006) The fuel gauge does not go above 7/8 on the IP gauge after a full customer fill or if the customer claims that they can only get about 12 or 13 gallons into the tank after the low fuel light comes on. The customer might also have a "Check gas cap" message or a P0455 in the PCM. Use this procedure:

Drain the fuel tank of all fuel.
Drop tank out of vehicle.
With tank sitting on its bottom, check the level sensor resistance - it should read at least 249 ohms.
Lip tank over onto its top-side, check the level sensor resistance - it should read 40 ohms Be sure tank is completely drained before doing this.
These last two steps are referred to as a 'flip-check'.

Remove sender from the tank and do a resistance sweep of the sensor to verify it reads from 249/250 to 40 ohms, from bottom to top, respectively.
If sensor does not verify correct resistance when it is outside of the tank, replace sensor.
If sensor checks out good, put sender into a BRAND NEW TANK and repeat flip-check to verify all is correct inside the tank.
If flip-check does not verify a good system, remove sender and install into a new tank until verified.
If flip-check is good, install tank Assy into vehicle, re-fuel to full and verify IP gauge is correct, and return to customer. Hope this helps.

If you take it apart look at the fingers on the contacts. If they are broken replace the level sensor. 90% of the time thats the problem. Also for the check engine light have it scanned and see what code it is. It might have something to do with the fuel level, but it could also be something else.