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Open/Closed Loop

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Hi all,

In the process of reflash tuning via HPtuners a 1GR-FE supercharged engine in my Toyota Hilux and whilst logging I've notice under "fuel system status" changing from closed to open loop which I understand but on decel OL Drive also appears.

So what is OL Drive?


Hello Phil

this will help you understand

ol is open loop

Fuel system status will display more than just Closed Loop (CL) or Open Loop (OL). You might find one of the following messages: OL-Drive, indicating an open-loop condition during power enrichment or deceleration enleanment; OL-Fault, indicating the PCM is commanding open-loop due to a system fault; CL-Fault, indicating the PCM may be using a different fuel control strategy due to an oxygen sensor fault.

Hi Ross,

I had a closer look and sure enough when OL Drive appears, both STFT fall to zero% and lamba risers to 1.23 indicating deceleration enleanment as you mentioned.

Thank you