The 2000 Chrysler Cirrus does
not have a fuel reset button in the traditional sense like some vehicles have for fuel economy calculations. There's no button to press to reset the fuel gauge itself, nor a readily accessible button to reset a trip computer related to fuel economy.
If you're experiencing fuel gauge issues, the problem likely lies with the gauge itself, the sending unit in the fuel tank, or a related electrical component. You'll need to have a mechanic diagnose the problem.
