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Old 11-29-2010, 09:07 AM   #98
Poolside OP
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Joined: Apr 2003
Location: Long Beach, CA
Oddometer: 11,865

The chart above is how the EFI on the 1100/1150 and 1200 operates. Most EFI systems operate very similar to this.

Start at the top of the blue column and work your way down. The blue column lists a common sequence of rider inputs. Traveling at a constant speed, rolling on the gas, speed increase, rolling off the gas, speed decrease.

The green boxes are the ECU subroutines, or algorithms if you like, that 'execute' based on what the rider is doing with the throttle. The subroutines are a set of instructions and procedures to carry out a particular task.

The white boxes are what the subroutines do.

As you can imagine, the chart somewhat generalized, but all the significant functions are there. The parts relevant to the BMW ECU are included. (That is, except for 'Start' and 'Idle'. I'll fill them in later.)

JJ and I will go into more detail about the chart, and explain more about the rider inputs and ECU subroutines.

[Edit] Regarding the empty boxes on the table. The boxes aren't empty per se. Rather, it's simple how EFI works. For example, Tip-in doesn't trigger the Overrun Fuel Cutoff subroutine, so that box is 'ghosted'.


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Poolside screwed with this post 12-04-2010 at 10:36 PM Reason: Clarify 'empty boxes'
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