How To Test The MAF Sensor (2.4L, 3.0L Mitsubishi 1999-2004)

The mass airflow sensor on your Mitsubishi vehicle (or Chrysler Sebring or Dodge Stratus) can be tested without a scan tool and in 4 easy steps. All you'll need is a digital multimeter that can read Hertz frequency.

Since quite a few Mitsubishi vehicles use this MAF sensor (and Chrysler Sebring and Dodge Stratus), at the bottom of this page, you'll find a complete list of vehicle that use this type of MAF sensor. By the way, this sensor is known as the volume air flow sensor in Mitsubishi tech speak.

You can find this tutorial in Spanish here: Cómo Probar El Sensor MAF (2.4L Mitsubishi) (at: autotecnico-online.com).

Symptoms Of A Bad Mitsubishi MAF Sensor

The most obvious one is that the CHECK ENGINE light (CEL) will be on on your instrument cluster and driving you nuts. Here are a couple of others:

1. A MAF sensor diagnostic trouble code (DTC) stored in your vehicle computer's memory.
   • P0101: Volume air flow circuit range/performance problem.
   • P0102: Volume air flow circuit low input.
   • P0103: Volume air flow circuit high input.
2. Lean and/or Rich Diagnostic Trouble Code(s).
   • P0171, P0174
3. Fuel trim diagnostic trouble code(s).
4. No power when you accelerate the car or truck.
5. Black smoke coming from the tail-pipe.
6. Your car or truck or SUV may idle rough and stall.

What Tools Do I Need?

You'll need a digital multimeter that can read Hertz (Hz) frequency (don't have a digital multimeter that can read Hertz frequency? Click here to see my recommendations: Buying A Digital Multimeter For Automotive Diagnostic Testing). As mentioned earlier, you don't need an automotive scan tool to test the MAF sensor. Having said that... a scan tool is one of those MUST have tools to be able check and diagnose today's modern cars and trucks, but for the tests in this article you don't need one.

Circuit Descriptions Of The MAF Sensor Connector

This Mitsubishi mass air flow (MAF) sensor has a total of 7 wires coming out of the connector. Although you won't be testing every single circuit, I've included the Circuit Descriptions of all them anyway for your viewing pleasure.

• Circuit labeled 1:
  • 5 Volt Reference Voltage
• Circuit labeled 2:
  • Barometric Pressure Sensor Circuit
• Circuit labeled 3:
  • MAF Signal Output.
• Circuit labeled 4:
  • Power (12 Volts) Circuit.
• Circuit labeled 5:
  • Sensor Return (Ground) Circuit.
• Circuit labeled 6:
  • Intake Air Temp Sensor Circuit.
• Circuit labeled 7:
  • MAF Reset Signal Output Circuit.

I did not include the color of the wires because as long as you're able to identify them by the number in the photo, you'll be OK. Also, the color of the wires in the photos may not be the color of the wires of the MAF on your specific vehicle and again this is no cause for concern.

TEST 1: Testing The Power Circuit For 12 Volts

The very first thing that has to be checked is that the MAF sensor on your Mitsubishi vehicle (or Chrysler Sebring or Dodge Stratus) is getting power (10 to 12 Volts), since without this voltage it won't work.

You can use a 12 Volt test light or a multimeter for this test, although the following test steps assume you're using a multimeter:

1. 1

   Place the multimeter in Volts DC mode and disconnect the MAF sensor from its connector.

2. 2

   Connect the red multimeter test lead to the wire identified with the number 4 (see photo above) using an appropriate tool.

3. 3

   Connect the black test lead of the multimeter to a good Ground point on the engine or to the battery negative (-) terminal.

4. 4

   Turn the key to the ON position and observe the voltage value the multimeter registers.

5. 5

   The multimeter should register between 10 to 12 Volts DC.

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

CASE 1: The multimeter registered 10 to 12 Volts DC (or the if the test light came on), then this indicates that the MAF sensor is getting juice (12 Volts). The next step is to verify that it's also getting a good Ground, go to: TEST 2: Testing The Ground Circuit.

CASE 2: The multimeter DID NOT register 10 to 12 Volts DC (or the if the test light DID NOT come on), your next step is to find out why this voltage is missing since without power, the MAF won't work. Repairing the cause of the missing voltage will solve the MAF issue/problem lighting up the check engine on your car.