DougRaymond
New member
What is the feedback parameter for closed vs open loop operation?
The O2 Sensor provides the feedback signal in closed loop operation ("control"). The Motronic uses it for more precise control of the Air-to-Fuel ratio whenever possible. A feedback variable is said to "close the control loop".
When conditions make feedback not possible, the Motronic runs 'open loop', providing a calculated amount of fuel for a given throttle position. This gets the job done, but less efficiently. In Open Loop Control the Motronic does not look at the results of combustion, the amount of O2 in the exhaust.