How To Test The Ford Mass Air Flow (MAF) Sensor

Testing the Ford mass air menses (MAF) sensor on all of the Ford, Lincoln and Mercury cars and trucks is a very elementary test that can be done without a scan tool. All you need is a multimeter. I recommend using a digital multimeter merely an analog multimeter tin besides exist used.

Ford has used a Hot-Wire type mass air flow sensor for many years that either comes with or without an internal air temperature sensor. If the MAF sensor has six wires, then this is a dead giveaway that it has the air temp sensor integrated within. If the Ford MAF sensor on your car has 4 wires, and then it does not accept an air temp sensor integrated within it (the air temp sensor volition exist somewhere on the air duct that connects the MAF sensor to the throttle body or somewhere on the intake manifold.

NOTE: At that place are several different Ford MAF sensors types. These come in either a black or light greyness body and with 6 or 4 wires in the connector. Regardless of what colour body the MAF sensor has or the amount of wires in the connector, they are all tested in the aforementioned fashion!

En Español You can observe this tutorial in Spanish hither: Cómo Probar El Sensor De Flujo De Aire (Sensor MAF) de Ford (at: autotecnico-online.com).

If your Ford or Mercury vehicle uses the MAF sensor in the round Canister Air Filter associates, go here: Ford MAF In Round Canister Air Filter Associates.

Common Symptoms Of A Bad Ford MAF Sensor

This is not the most definitive list on the discipline, but does embrace the majority of symptoms I've seen on these types of Ford mass air flow sensors:

  1. MAF Codes that calorie-free up the check engine light (CEL) on your musical instrument cluster.
    1. P0102 MAF Signal Low Input to PCM.
    2. P0103 MAF Signal High Input to PCM.
    3. P1100 MAF Circuit Intermittent Voltage Input.
    4. P1101 MAF Sensor Circuit Output Voltage depression During KOEO Self Test.
  2. MAF sensor malfunction that DOES Non light up the check engine low-cal (CEL).
  3. Lean and/or Rich code(due south).
  4. Fuel Trim lawmaking(south).
  5. A tremendous lack of power upon acceleration.
  6. Blackness smoke coming from the tail-pipage.
  7. Bad gas mileage.
  8. Vehicle may idle crude and stall.

Is The MAF Sensor Just Muddied?

The about common gear up I've performed on the bulk of MAF sensor problems on Fords have been cleaning it. Now, the symptoms that accompany a dirty (contaminated) Ford MAF sensor are not that harsh or noticeable on engine functioning (of course this is non an absolute truth).

What I hateful is that a dingy MAF sensor doesn't wreak a lot of havoc on the car or truck. Usually the biggest complaints are bad gas mileage and/or a slight lack of power. So how do I diagnose a muddied/contaminated Ford MAF sensor? Well:

  1. I'll remove it (before I starting time any testing) and eye-ball the 2 'hot-wires' to see if they are covered in fuzz or other material (you lot can come across an case of this here: Dirty MAF Sensor Example).
  2. Or, I'll test it get-go following the guidelines set in this article, to come across if information technology'due south producing a MAF signal.
  3. If it is producing a bespeak, but the signal'south response is also slow to changes in throttle position, then I know to look into cleaning it.
  4. If yous need to clean it, here's the article: How To Make clean The Ford Mass Airflow Sensor (at troubleshootmyvehicle.com).

Why does it get muddy/contaminated? Well, this MAF sensor hands becomes contaminated with dirt and stuff from the air filter non performing its job or the box that holds the air filter is broken or not sealing correctly. The Ford MAF sensors are some of the easiest MAF sensor to clean. All it takes is to remove the two torx head screws that concur it in identify and spray-clean the ii hot-wires with a MAF sensor Cleaner.

Air Leaks

The second virtually common problem I have encountered on nearly Fords (Mercurys and Lincolns) over the years is air leaks betwixt the MAF sensor and the throttle torso.

Information technology is crucial, yep very critical that yous kickoff check that in that location are no air leaks betwixt these two. Air inbound after the mass air menses sensor into the engine volition negatively impact fuel injection. And will skew the results of your tests which could result in the replacement of a good MAF (and in the procedure throwing money away).

How do you check for air leaks? With your optics and hands. That's right, no special tools required. Just eyeball and physically shake/movement the ducting to see if it's loose or disconnected.

MAF Sensor Excursion Descriptions

Whether your Ford, Mercury or Lincoln car has a MAF sensor with iv or 6 wires (coming out of the connector) their circuits share the circuit descriptions.

Photo one of 2, in the image viewer, is that of a 4 wire MAF sensor. This is a non intake air temp (IAT) sensor MAF sensor.

Photo ii of two is of a MAF with vi wires, since it has the IAT sensor integrated with the associates.

Yous'll notice that the photos (in the paradigm viewer) have the MAF connectors lettered A thru' F (If you look closely at the MAF sensor housing, you'll see these letters on it likewise). I'll be using these letters for the circuit descriptions.

Here's the clarification of each circuit beneath:

  1. Letter F:
    1. Intake air temperature (IAT) sensor circuit (not applicable if you have a 4 wire MAF sensor).
  2. Alphabetic character D:
    1. MAF Signal.
  3. Alphabetic character C:
    1. Basis that the ECM provides.
  4. Letter B:
    1. Ground.
  5. Alphabetic character A:
    1. 12 Volts.
  6. Letter Eastward:
    1. Air Temp. sensor excursion (not applicable if you have a 4 wire MAF sensor).

Using a wire-piercing probe is the most effective and like shooting fish in a barrel way of getting to the MAF signal, since you don't risk damaging the female terminals of the connector by probing them direct. If you need to see what this tool looks like, click here: Wire-Piercing Probe. Contained of the method y'all utilise, be careful not to impairment the wire or the female terminal. Take all prophylactic precautions.

Another important thing to note is that the colour of the wires (coming out of your Ford, Lincoln or Mercury motorcar or truck) does not matter. In other words, the excursion description/job of the wire is the same regardless of Make/Model and color of the wire.

Of import: All of the tests are ON CAR TESTS, practice not remove the mass air menses sensor from the vehicle or from its plumbing.

Summary Of The MAF Sensor Tests

OK, you're gonna' starting time past checking the basics. These are 12 Volts and battery Ground to the MAF sensor. After that, we'll test the bodily performance of the MAF sensor as the engine is running. Use a digital multimeter for all tests where a multimeter is chosen for.

The MAF sensor produces an analog voltage signal. This MAF point's DC voltage is directly related to amount of air the engine is breathing. Therefore, if the engine is animate in more air at 2500 RPM's that at an idle of 900RPM's the voltage output volition be greater at 2500 RPM's than at idle.

Now, when testing this voltage signal, the important affair to know is not an bodily Volts number at a specific RPM, but to await for crazy and extreme fluctuations in the voltage signal that practice not correspond to the actual air intake (RPM'south) of the engine or no signal at all. For example: If at Idle the voltage reading starts to spike up and down without you lot accelerating the engine or if in that location's no signal at all.

In the TEST 4 section of this article, I'll show how you'll use a base voltage reading at idle from the MAF sensor that volition help y'all to confirm that the MAF sensor is bad or non.