How To Test The MAF Sensor (2002-2003 3.5L Maxima)

You can easily test the mass air flow (MAF) sensor on your 2002-2003 3.5L Nissan Maxima with a multimeter and in this tutorial, I'll explain how.

I've also included an easy to read MAF sensor wiring diagram at the end of this tutorial to further help you.

Common Symptoms Of A Bad Nissan MAF Sensor

Here's a basic list of symptoms that your 3.5L Nissan Maxima will experience when the mass air flow sensor goes bad:

1. MAF Codes that light up the check engine light (CEL) on your instrument cluster.
   • P0100,
2. MAF sensor malfunction that DOES NOT light up the check engine light (CEL).
3. Lean and/or Rich code(s).
4. Fuel Trim code(s).
5. A tremendous lack of power upon acceleration.
6. Black smoke coming from the tail-pipe.
7. Bad gas mileage.
8. Vehicle may idle rough and stall.

Circuit Descriptions Of The Nissan MAF Sensor Connector

The mass air flow sensor, on the 2002-2003 3.5L Maxima has the intake air temperature (IAT) integrated into its assembly.

For this reason, you'll see 5 wires sticking out of its connector. You can see the MAF wiring diagram here: MAF Sensor Wiring Diagram 2002-2003 3.5L Maxima.

Here's a brief description of each one:

MAF Sensor Circuits (2002-2003 3.5L Nissan Maxima)
Pin	Wire Color	Description
1	WHT	MAF Signal
2	RED	5 Volts DC
3	BLK	MAF Ground
4	RED/GRN	Battery Power
5	YEL/GRN	IAT Signal

I recommend using a wire-piercing probe to test the signals in the wires, since this method will be the most effective and easiest way of getting to the signal. If you need to see what this tool looks like, click here: Wire-Piercing Probe. Independent of the method you use, be careful not to damage the wire(s). Take all safety precautions.

TEST 1: Making Sure The MAF Sensor Is Getting Power

The first thing we're gonna' do is make sure that the MAF sensor is getting battery power.

This battery power come's from your Maxima's ECM power relay and is fed to the MAF sensor thru' the red with green stripe (RED/GRN) wire of the harness connector.

This RED/GRN wire is labeled with the number 4 in the photo above.

OK, these are the test steps:

1. 1

   Place your trusty multimeter in Volts DC mode.

2. 2

   Probe the MAF sensor wire, that's identified with the number 4 in the photo, with the red multimeter test lead.

3. 3

   Connect the black test lead of the multimeter to the battery negative (-) terminal.

4. 4

   Turn Key On but don't crank or start the engine. This will power up the fuel injection system.

5. 5

   Your multimeter should read 10 to 12 Volts DC if power is available at the RED/GRN wire.

Let's take a look at what your test results mean:

CASE 1: Your multimeter registered 10 to 12 Volts. This result indicates that the Maxima's MAF sensor is getting juice (power). The next step is to test the Ground circuit, go to: TEST 2: Making Sure The MAF Sensor Is Getting Ground.

CASE 2: Your multimeter DID NOT register 10 to 12 Volts. Recheck all of your multimeter connections and retest. If still no voltage, then this result exonerates the Maxima's MAF sensor as the cause of the MAF code or MAF issue, since without this voltage, the MAF sensor will not produce a signal to the computer.

Finding and repairing the source of this missing voltage will resolve the MAF sensor issue with your Nissan Maxima.