Gas gage is gaga!

Yeah i have a 2005 mecury montego all wheel drive car. In the last year, sometimes the gas gage will drop from a quarter tank to nothing sometimes on a sharp right turn. once i have ran out of gas because the message says i have for instance, 30 miles to empty. so my fianc?e got the book that came with car and there was actual reset instructions which he did. But it didnt work. Called my dealership and the mechanic said he had never heard of this, although its in the car manual. so whats your thoughts on this strange behavior? Or is because i am a true nascar fan and always want to go left…lol

Most cars today have a digital interface between the sending unit in the tank and the gauge in the dash. That is, the analog measurement provided by the sending unit is digitized and sent to a computer. This is where the “miles to empty” and other info is calculated. Then it goes to the dashboard where it is converted back to a voltage level to power the gauge.

This happens to me on occasion but it usually resets itself the next time I start up the car. If it happens when I’m low on gas, I just fill up. That should reset everything when the float in the tank goes to its topmost position.

When the gauge drops to zero, you have a data freeze so you cannot depend on the miles to go display. If you understand this, you should not run out of gas. Use your odometer trip function to keep track of when you need gas. You will probably find the cost to repair a lot higher than you want to spend, car computer prices have not followed the PC price trend.