Open Loop and Closed Loop Conditions

[WRL69]

I'm trying to do "On Borad Diagnostic System", from the Service manual, but I don't understand what are "Open Loop Condition" and "Closed Loop Condition".

 

Could anyone explain me?

 

Regards,

Edited November 5, 2006 by WRL69

[sw]

Open loop defines the engine operation when the fuel ratio is calculated with consideration to only input signals from the main sensors in the program style (MAF / SD / VAF / AN). Programmable fuel management systems can be operated in 100% open loop very effectively.

 

Closed loop defines the engine operation when the fuel ratio is calculated with consideration taken from the main sensors and feed back sensors like the exhaust oxygen sensor. Closed loop operation is devoted to emissions, economy, and a Stoichmetric fuel ratio of 14.7:1.

Edited November 5, 2006 by sw

[WRL69]

O.K. But, how can I operate the engine on each of both Open Loop Condition and Closed Loop Condition? What I have to do?

 

Regards,

[88pathoffroad]

I don't think you can selectively change modes like that. You could probably just disconnect the O2 sensor, after warm-up it'd just run in open loop by itself.