When to use closed loop or open loop?
Open loop is when the ECU is not referring to the o2 sensor for feedback. Meaning that the o2 sensor might as well not be there, because the ECU is not using it to modify its timing and fuel maps. Closed loop is when the ECU does refer to the o2 sensor for feedback.
When to use open loop or closed loop fuel control?
Open loop STFT is used on some PCM’s when the O2 sensors are showing signs of operation (O2 Readiness), however the closed loop enable ECT has not been reached. In this mode the STFT’s may function. The final mode is Closed Loop and in this mode the full closed loop fuel controller is operational.
What happens when a car is in closed loop?
If the computer is in closed loop and it’s not getting the expected readings from the oxygen sensors, it will self adjust and add or subtract more or less fuel to achieve the expected emissions readings. Fuel trim readings can be short term or long term. Fuel trim readings are constantly changing.
How to tune closed loop and open loop O2?
1. The Percent (%) of fuel that can be added or subtracted from the fuel map. 2. The coolant temperature when closed loop o2 will begin. 3. The engine RPM when closed loop o2 will begin. 4. Conditions when closed loop o2 should be turned off. 5. The target A/F value based on load or MAFcfm, and engine speed.
Open loop STFT is used on some PCM’s when the O2 sensors are showing signs of operation (O2 Readiness), however the closed loop enable ECT has not been reached. In this mode the STFT’s may function. The final mode is Closed Loop and in this mode the full closed loop fuel controller is operational.
Open loop is when the ECU is not referring to the o2 sensor for feedback. Meaning that the o2 sensor might as well not be there, because the ECU is not using it to modify its timing and fuel maps. Closed loop is when the ECU does refer to the o2 sensor for feedback.
1. The Percent (%) of fuel that can be added or subtracted from the fuel map. 2. The coolant temperature when closed loop o2 will begin. 3. The engine RPM when closed loop o2 will begin. 4. Conditions when closed loop o2 should be turned off. 5. The target A/F value based on load or MAFcfm, and engine speed.
If the computer is in closed loop and it’s not getting the expected readings from the oxygen sensors, it will self adjust and add or subtract more or less fuel to achieve the expected emissions readings. Fuel trim readings can be short term or long term. Fuel trim readings are constantly changing.