TEST 1: Testing The Power (12 V) Circuit

Making Sure That The MAF Sensor Is Getting Power. Mass Air Flow (MAF) Sensor Test Nissan Sentra 1.6L (1995-1999)

Unlike many of the MAF sensors out there, the 1995, 1996, 1997, 1998, 1999 Nissan Sentra 1.6L mass Air Flow (MAF) sensor uses only three wires to perform its magic. In this section we'll test each one to see if the right signal is present.

The very first thing that we'll do is check that the MAF sensor is receiving 12 volts.

The wire that feeds these 12 Volts is the one labeled with the number 3 in the photo above.

Let's get started:

  1. 1

    Place your multimeter in VOLTS DC mode.

  2. 2

    Disconnect the MAF sensor connector from the MAF sensor.

  3. 3

    With the red multimeter test lead and an appropriate tool, probe the MAF sensor wire labeled with the number 3 shown in the photo above.

  4. 4

    With the black multimeter test lead probe battery negative (-) terminal.

  5. 5

    Turn the key on but don't crank or start the engine.

  6. 6

    You should see 12 Volts on the multimeter if the MAF sensor is being fed power.

Let's examine your test result:

CASE 1: The multimeter registered 12 Volts -All is good in the neighborhood. The next step is to make sure your Nissan Sentra's MAF is getting Ground. Go to: TEST 2: Testing The Ground Circuit.

CASE 2: The multimeter DID NOT register 12 Volts -The MAF sensor is not the problem. Without this voltage the MAF sensor will not work.

Although it's beyond the scope of this tutorial, your next step is find out why power is missing and restore it.

TEST 2: Testing The Ground Circuit

Making Sure That The MAF Sensor Is Getting Ground. Mass Air Flow (MAF) Sensor Test Nissan Sentra 1.6L (1995-1999)

In the previous test we checked that the sensor was receiving 12 Volts. Now we'll check that the MAF sensor is getting a good ground. This ground is provided by the ECM internally.

The wire that supplies ground to the MAF sensor is the one labeled with the number 2 in the photo above.

Be careful and take extreme care not to short-circuit this wire to ground or power as you're probing it.

Let's get started:

  1. 1

    Place your multimeter in VOLTS DC mode.

  2. 2

    Disconnect the MAF sensor connector from the MAF sensor.

  3. 3

    Probe the MAF sensor wire labeled with the number 2 with the black multimeter test lead (and the appropriate tool).

  4. 4

    Connect the red multimeter test lead probe battery positive (+) terminal.

  5. 5

    Turn the key on but don't crank or start the engine.

  6. 6

    You should see 12 Volts on the multimeter if the MAF sensor is being fed power.

Let's interpret your Ground test result:

CASE 1: The multimeter registered 12 Volts -This is the correct and expected test result.

Now for the last test, which is testing the MAF signal itself. Go to: TEST 3: Testing The MAF Signal With A Multimeter.

CASE 2: The multimeter DID NOT register 12 Volts -The MAF sensor is not the problem. Without this ground the MAF sensor will not work.

Although it's beyond the scope of this tutorial, your next step is find out why this Ground is missing and restore it.