In three easy test steps, this article will teach you how to test the 1995, 1996, 1997, 1998, 1999 Nissan Sentra 1.6L MAF sensor on the car.
Before jumping into the tests, read this section. Here you're going to find the basic working theory of the Nissan Sentra MAF sensor, its symptoms when it goes bad and what tools to use to test and diagnose it.
Now, case this is not the article you're looking for, there are several other Nissan MAF sensor test articles:
- How To Test The Nissan MAF Sensor Frontier, Quest, Pathfinder, and Xterra 3.3L V6 (1999-2004).
- How To Test The Nissan MAF Sensor Pathfinder 3.5L V6 (2001-2003).
- How To Test The Nissan MAF Sensor: Maxima 3.0L V6 (1995-1999).
- How To Test The Nissan MAF Sensor: Sentra 1.8L 4 cyl. (2000-2002).
You can find this tutorial in Spanish here: Prueba: Sensor de Flujo de Aire (MAF) Nissan Sentra 1.6L (1995-1999) (en: autotecnico-online.com).
Basic Working Theory
The Sentra MAF sensor measures the amount of air that the engine is breathing and converts this measurement into a DC voltage signal that ranges between 0.5 to 5 Volts DC. As you may already know, it's this signal that the computer uses to calculate how much fuel to inject.
The MAF Signal's voltage is directly related to amount of air the engine is breathing. Now, since the engine will breathe in more air at 2500 RPMs than at an idle of 900 RPMs, the sensor's voltage signal will be lower at idle than at a higher engine speed. And knowing this is the key to successfully diagnosing the MAF sensor.
Usually, at idle with the engine at its normal operating temperature, the Sentra MAF sensor produces a signal of 1.0 Volts to 1.7 Volts. Now, when testing this voltage signal, the important thing to know is not an actual Volts number at a specific RPM, but to look for crazy and extreme fluctuations in the voltage signal that do not correspond to the actual air intake (RPMs) of the engine or NO SIGNAL AT ALL.
In the TEST 3 section of this article, I'll show how you'll use a base voltage reading at idle from the MAF sensor that will help you to confirm that the MAF sensor is bad or not.
Symptoms Of A Bad Nissan Sentra MAF Sensor
The most common symptoms of a bad MAF sensor are:
- A MAF sensor code.
- Lean and/or Rich code(s).
- Fuel Trim code(s).
- A tremendous lack of power upon acceleration.
- Really bad gas mileage.
- Black smoke coming from the tail-pipe.
- Vehicle may idle rough and stall.
What Tools Do I Need To Test The MAF Sensor?
This MAF sensor can be tested without using expensive testing equipment. You don't even need a scan tool. Here's the list:
- A multimeter.
- Wire-piercing probe.
Test Info: A Description Of The Circuits
Unlike many of the MAF sensors out there, the Nissan Sentra MAF sensor uses only three wires to perform its magic.
As you've already noticed, the photo has the MAF connector numbered 1 thru' 3. I'll be using these numbers for the circuit descriptions. Here's the description of each circuit below.
- Number 1- MAF signal.
- Number 2- Ground provided by the ECM internally.
- Number 3- 12 Volt battery power.
The safest way to test these circuits, and the method I always use, is using a wire piercing probe. (Wire Piercing Probe). Using this probe, I don't have to disconnect the MAF sensor's connector to probe the front of the female terminal and possibly risk damaging it.
Independent of the method you use, be careful not to damage the wire or the female terminal. Take all safety precautions.