2015 nissan sentra mass air flow sensor problems

“Long-term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation of the short-term fuel trim from the central value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an increase in fuel volume if it is lean.

The signal from air-fuel ratio (A/F) sensor 1 indicates whether the mixture ratio is RICH or LEAN compared to the theoretical value. “Short-term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical value. Fuel trim includes short-term fuel trim and long-term fuel trim. “Fuel trim” refers to the feedback compensation value compared to the basic injection duration. This is then computed in terms of “injection pulse duration” to automatically compensate for the difference between the two ratios. Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic changes during operation (i.e., fuel injector clogging) directly affect the mixture ratio. However, the basic mixture ratio is not necessarily controlled as originally designed. The ECM controls the basic mixture ratio as close to the theoretical mixture ratio as possible. This feedback signal is then sent to the ECM. The mixture ratio feedback control system monitors the mixture ratio signal transmitted from air-fuel ratio (A/F) sensor 1. If you don't have one, you can perform the 'HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION' procedure manually, or you can just disconnect the battery and wait.Įxtracts from the Engine Control (EC) section of the 2006 Xterra service manual Note that steps 6 through 8 are easy if you have a language. I haven't checked the manuals for other years yet, but I would ASSUME (as in maybe YOU shouldn't) that the procedure is the same. Here are the relevant excerpts from the 2006 service manual. I would appreciate a second opinion from somebody, please, in case I'm sadly mistaken!

It takes a bit longer than that, but the basic trick is to disconnect the MAF for at least 5 seconds. Here's how to reset the 'air-fuel ratio self-learning control value' (discussed along with 'ECU relearning' as 'reset the ECU' or 'ECU reset' in other threads) without disconnecting the battery, waiting for some unknown number of minutes or hours, and losing other settings as the radio station presets in the process. I was looking in the service manual for information about the mass air flow sensor when I stumbled upon a handy procedure.

2015 nissan sentra mass air flow sensor problems