October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

Open Loop

When engine is cold and engine speed is greater than 400 RPM, PCM/VCM operates in "open loop" mode. In "open loop" mode, PCM/VCM calculates air/fuel ratio based upon coolant temperature and MAP or MAF sensor readings. Engine remains in "open loop" mode until O2S reaches operating temperature, coolant temperature reaches a preset temperature and a specific period of time has elapsed after engine starts.