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Hello,

As of this morning my car has been in engine maintenance all day. 45 min drive in to work (20+miles) and 45 min drive back same distance. It said maintenance required, but is not giving me a % Complete at all, the engine will not stop running and battery is full.

Any thoughts?

Thanks,

Adam
 

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Discussion Starter #2
Hello,

As of this morning my car has been in engine maintenance all day. 45 min drive in to work (20+miles) and 45 min drive back same distance. It said maintenance required, but is not giving me a % Complete at all, the engine will not stop running and battery is full.

Any thoughts?

Thanks,

Adam
 

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Are you sure it's Engine Maintainence, often called EMM here on the forum, and not Fuel Maintenance ( FMM)? I

f the car thinks the average age of your gasoline is more than 1 year, it will run the engine to deplete it, and get you to add enough fresh fuel to get the average age less than one year.

Where was the last time you added gas? How old do you think the fuel is in your car?

-Lumos
2014 gen 1
 

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My first guess would also be the car is running fuel maintenance not EMM.
How much gas is in the fuel tank? Once running the gas engine has used up some of the gas in the fuel tank to where the remaining fuel is half a tank or less fill the tank with an equal amount of fresh gas. The Volt will record that a sufficient quantity of fresh fuel was added to the fuel tank so that the average age of the fuel in the tank is now 6 months age. This should suspend the Fuel Management Mode from running for approximately 6 months.
 

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If you bought your car about a year ago and haven’t put gas in your tank since then, it is possible your Volt is running a Fuel Maintenance Mode (FMM), rather than an Engine Maintenance Mode (EMM) procedure.

If it’s an FMM, you can confirm it by starting the car. Each time you start the car, a message should come up on the driver’s display saying the car is undergoing an FMM episode.

The FMM runs when the average age of the gas in the tank is ~12 months old to make sure your gas doesn’t get too old. During the FMM, the engine will run at all times to use up the "old" gas (even with a full charge, you won’t be able to run on battery power). The FMM ends when you run out of gas or you do something to lower the average age of the existing gas. Some people drive until they run out of gas, and then decide if they want to fill the tank or only put a little in because they don’t use much. This gas is now all "new" gas, so the next FMM is postponed for about 12 months. Others don’t want to drive far enough to use up the old gas, so instead they add some gas to the existing amount. This will lower the "average" age and end the FMM, but the timing for the next FMM depends on how much new was added to how much old gas. If you add enough new gas to double the existing amount (for example, adding 2 fresh gallons to 2 gallons of 12 month old gas), the "average age" is reduced from 12 to 6 months, postponing the next FMM for only 6 months.
 

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Agreed on the FMM not EMM. The 6 week Engine Maintenance Mode (EMM) only operates for a few minutes but Fuel Maintenance Mode (FMM) runs the old gas out (~1 year old) until about 1 gallon remain and prompts you to add fuel. Most 95%+ EV mode drivers usually only add a gallon or two when that occurs since they almost never burn a whole tank in a year.
 

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I generally wait tell the car offers to direct me to the closest gas station before adding gas.
 
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