Loop Status Bn 1 Sen. 1

OPEN/CLOSED
A Closed Loop operation displayed indicates that the ECM is controlling the fuel delivery according to the oxygen sensor voltage. In an Open Loop operation, the ECM ignores the oxygen sensor voltage and bases the amount of the fuel to be delivered on other input sensors. At extremely high ambient temperatures or when towing a trailer, it is possible for the system to remain in an Open Loop operation in order to control the catalytic converter temperatures.