Keeping Flexible with New Electronics

What your technicians need to know about electronic controls on clean diesels and flex-fuel vehicles.

The system makes converting fleet vehicles to E85 a long-term cost-saver, Sremac says.

“First of all, there’s the (reduced) cost of fuel—E85 is around 50 cents a gallon cheaper than gasoline in the Midwest,” he says. “There’s always been this stigma that you lose 25 or 30 percent fuel economy with E85, and we found you get anywhere from 0-5 percent loss, and we have that on our emissions testing. If you’re putting on 25,000 miles a year, you’ve paid for that kit in the first year.”

With many states offering incentive programs to “green” fleets, the cost could be even less.

“You could put a kit on in the state of Illinois and you’d get an 80 percent rebate back,” Sremac says. “You’d probably get a return on your investment in about two months.”

The company invested more than a million dollars in the system, including certifying each vehicle model as required by the EPA.

“For us to certify 80 percent of the fleets out there, we have to go in and certify 30 different models,” he says. “You have to be able to keep a certain emission level for 100,000-plus miles, so it’s very complicated, very difficult and very expensive.”


The Flex Fuel U.S. system looks quite simple, with a processor, injector, alcohol and flex fuel sensors, as well as other sensors that connect to the engine. It’s designed that way so technicians can install it without problems, Sremac says, and troubleshooting is also supposed to be basic.

“If something goes wrong with the system, the car’s either going to go rich or lean, depending on whether you’re running gasoline or ethanol, so you would automatically get a check engine light,” he says. “So if you kick off a light, you bring it into your technician and he plugs in an OBD-II scanner and he sees it’s too lean or rich, you know maybe there’s something wrong with the system.

“And then you can go check it and see if there’s power, and you can take one of those little noid lights and plug it right into one of the test ports we have to make sure the light is flicking on and off to make sure the injector is working,” he says. “There are ways to check the system out; it’s not very complicated.”


Curtis Lacy, president of marketing and distribution for the Boise, ID-based Full Flex International, said the relatively low cost of ethanol conversion systems like theirs can help fleets save serious cash.

“If you want to convert to CNG or LPG, you’re looking at anywhere from $1,500 to maybe $15,000, depending on the vehicle,” Lacy says. “With our system, you can convert from anywhere from $350 to under $500, depending on the size of your engine. And the conversion time takes 15-20 minutes. It’s a lot easier solution than buying a whole new fleet of vehicles.”

Lacy says the system’s cold start feature is another advantage for fleets that operate in freezing temperatures.

“Ethanol is water-based so it makes it kind of funny in the winter to startup, but our cold start senses the different temperatures and will make necessary adjustments to bring in more fuel or to help warm the fuel up from the engine, so when you start the vehicle, it starts with no problem,” Lacy says.

Full Flex will fly its staff around North America to train technicians how to properly install and maintain the systems, though Lacy says there is not much to know outside of being able to understand an electronic code reader.

“If you can change your oil, you can install this,” he says.


Higher quality diesel fuel, advanced engines and better emission controls have brought “clean diesel” to many fleets, and new technologies have made diesel engines cleaner, quieter and more powerful. The electronic controls on these engines are also more sophisticated, with computers controlling the amount of fuel that flows from the injector.

Donn Frincke, assistant chief engineer for GM’s Duramax engine, says the 2007 emission standards prompted the company to tweak its electronic control system just a bit.

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