But sometimes the fuel level sensor contacts are too far gone to be fixed by a cleaning. If the fuel additive did not fix the problem, a failing or failed fuel sending unit is the most likely cause.

Within the fuel level sensor are small metal parts which send the readings to the driver’s dashboard and cause the light to flash.

It depends on how much you drive. The mass airflow sensor is a critical player in determining fuel mileage and exhaust emissions and one of the most important sensors in the vehicle in that respect.

The fix: GM will notify owners, and dealers will replace the rear tank fuel pump or update the fuel-level sensor software.

General Motors has agreed to pay to repair the fuel gauges in several GM SUVs, following a defect investigation by the National Highway Traffic Safety Administration.

Documents posted Thursday by the U.S. government say that the low-fuel-level sensor in the front tank can stick, causing the rear tank to over-fill the front tank.