Lifetime Premium Member
Date registered: Feb 2003
Vehicle: 1999 C-280. & 2000 SL500
Location: N/E Ohio, Rocky River
Mentioned: 0 Post(s)
Quoted: 1 Post(s)
FSS reset problems
MBCA Technical Library - Flexible Service System (Courtesy of Lynn Sorenson (R129)
"In doing research on oil quality throughout it's "life" in the engine, Daimler discovered that the breakdown in oil correlated directly with it's increased ability to conduct an electric current, or conversely, a decrease in the dielectric constant (less resistance to electrical current flow). They also determined that such driving habits as making frequent short trips, driving at high speed, and failure to replenish low oil levels can contribute to faster oil breakdown and the need for more frequent oil changes. Drum roll please....And so was born the Flexible Service System or FSS. With inputs from the oil sensor, coolant temperature sensor, engine control module and tachometer, the computer calculates the optimum interval for the next oil change and signals the driver accordingly. The exception to this system, I believe, is the 4-cylinder cars which do not have the oil sensors but utilize all other inputs to the computer. In practice, average "recommendations" are between 10- 12,000 miles, but, as always, your mileage may vary."
Just maybe the reason many people have a problem resetting the FSS after an oil change, including me, is the system needs to taste the new oil to verify that the oil has indeed really been changed. I tried to reset my FSS 8-10 times without success right after I changed the oil, came back 3-4 hours later after a drive and tried to reset it and it worked. What do you all think about that theory???