Hi,

I recently bought my 2013 Nissan Rogue used and have just realized that it does not produce any Long Term Fuel Trim data for my scan tool. When I use my scan tool to read for LTFT it's always 0. It does produce Short Term Fuel Trim data. I have already tried resetting ECU and been driving the car for more than 100 miles since the reset, but still no sign of LTFT data.

What is the meaning of this? How do I get my LTFT readout?

Thank you.

I don't know exactly how long it took for my LTFT to read after I reset the ECU, but it did take a while. I had the same question, I stopped checking, at some point I checked again and it was reading.

I have read somewhere online that usually it takes only about 50 miles for LTFT to pop up again after reset. I have also read somewhere that LTFT stuck at 0 may have to do with EVAP problems (somewhere a sensor is not sending signal to the ECU), which can cause bad mileage because a bad EVAP valve can have the effect of a vacuum leak (air-fuel mixture gets vented outside instead of being routed back to the combustion chamber, thus creating a lean condition). I am still hunting for the source of my bad fuel economy.

I have just cleaned my PCV valve yesterday. Next I am going to look into my canister purge valve, which is quite accessible. If that's not it then maybe there is an issue with the vapor canister purge solenoid, which is less accessible as it is behind the left rear wheel.

I will get to the bottom of this and I am not giving up.

My LTFT definitely took longer than 50 miles to come back. I drove for 50 miles trying to get rid of the permanent code and then had to do a drive cycle. Doing a drive cycle may have brought back the LTFT, not sure though.