AEM 30-71XX Infinity Stand-Alone Programmable Engine Mangement System Full Manual - Manual (Page 308)

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© 2014 AEM Performance Electronics
Infinity User Manual
FCS (Fuel Composition Sensor)
The Fuel Composition Sensor (FCS) is used for "flex" fuel. These vehicles can run on a more
environmental friendly ethanol based fuel which is commonly made from sugar cane or corn. It
has roughly 30% less energy than standard pump gas, depending on the blend. E85 is the most
common blend, which consists of 85% ethanol and 15% petroleum. This lack of energy does a
couple things: It causes an increase in fuel consumption, but increases the air/fuel cooling
characteristics as more fuel is required. Furthermore, ethanol has a much higher latency heat of
evaporation than gasoline which also increases the cooling efficiency properties.
The Infinity flex fuel system is based around the use of GM sensor P/N: 12570260 (shown below)
which outputs a varying frequency signal depending on the fuel composition and temperature.
This information can then be used to add more injector pulse width, advance the ignition timing,
and add boost pressure, if applicable.
For more information, go to Flex Fuel
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