Open and Closed Loop Operation

In addition to promoting efficient combustion and catalyst operation, a stoichiometric air/fuel ratio also promotes excellent fuel economy. This relatively lean mixture is desirable during cruise and idle operation; however, other operating conditions often require a richer air/fuel ratio. When the electronic control system ignores signals from the oxygen sensor and does not correct the air/fuel ratio to 14.7:1, the system is said to be operating in open loop.

In order to prevent overheating of the catalyst and ensure good driveability, open loop operation is required under the following conditions:

• During engine starting

• During cold engine operation

• During moderate to heavy load operation

• During acceleration and deceleration

During open loop operation, the ECU ignores information from the exhaust oxygen sensor and bases fuel injection duration calculations exclusively on the other input sensors.

Simple Car Care Tips and Advice

Simple Car Care Tips and Advice

Put an End to All Your Car Troubles. Does Your Car Break Down Often? Are You Spending More On Fuel Than You Thought You Would? Is Maintaining Your Car Eating Into Your Budget? Make Your Car Last Longer with Some Simple Do It Yourself Tips.

Get My Free Ebook


Responses

  • tom
    How to fix fault open loop in fuel system of camry?
    1 year ago
  • Ilaria
    What sets closed loop fuel toyota?
    4 months ago

Post a comment