How To Test a Ford Fiesta MAF

How To Test a Ford Fiesta MAF


The Mass Air Flow (MAF) sensor in your 1.6 liter turbocharged Ford Fiesta is a very important piece of your Ecoboost EFI puzzle. Providing real time data to your Ford PCM or ECU that’s essential to the operation and longevity of your engine, your car will run rough if there’s a problem with your MAF.

Today we’ll be showing you how to test a Ford Fiesta MAF by checking the wiring and making sure that power, ground and signal wires are all working. Our test vehicle is a 2014 Ford Fiesta with the 1.6 liter turbo engine in it. When you have MAF problems, OBDII trouble codes like P0174 or P0171 can arise, lighting your Malfunction Indicator Lamp (MIL) or causing your car to run poorly.

Before beginning our DIY How To test a Ford Fiesta MAF guide, you should make sure you know how to operate a multimeter or voltmeter. If you don’t know what those tools are, or how to use them, check out our DIY guide here.

How To Service Your Ford Fiesta MAF
How To Service Your Ford Fiesta MAF

If you know that your mass air flow (MAF) is already bad, go ahead and check out our DIY How To Service a Ford Fiesta MAF located here.

To gain the proper clearance in your Ford Fiesta engine bay, remove your plastic engine cover by pulling down and upward to lift off the tabs. With that removed, locate your MAF sensor which is mounted to the MAF housing inline with your Ford airbox.

Pull up on the red retainer clip so that you can disconnect the Fiesta MAF. Once you have the MAF connector removed, go ahead and inspect the wiring as shown and labeled below.


You will be using your multimeter to check the wiring of your MAF connector. You will be checking for switched power, low reference ground signal to see if your MAF is receiving power. Because your Ford Fiesta MAF is six pin connector, your air intake temperature sensor is the next component we’ll be testing in your MAF sensor.

Testing your Ford Fiesta MAF for Power


The first wire you’ll be checking is PIN 4 of your Ford Fiesta MAF connector. Your ignition key should be inserted into your steering column and turned to the “ON” position so that your engine sensors receive power and ground.


Put the black negative lead of your multimeter to your battery, and use the other lead to check this pin for switched power.  You should have 12 volts here at this pin. When checking the front of your MAF connector, never shove or forcefully put the multimeter probe to the front of the connector. Doing so may cause damage to the plastics, which may compromise the connection quality to your sensor.

Testing your Ford Fiesta MAF for Ground

The next wire on our how to test a Ford Fiesta MAF DIY guide is PIN 3. This is the low reference ground wire that is provided by your ECM and grounds the MAF sensor so it’s working properly.


The next wire we’ll be checking is the 5 volt switched power to PIN 2, and this is the power for your air intake temperature sensor.


Problems with this wiring can lead to AIT issues, which could trigger OBDII trouble codes on your Ford dash. If your MAF connector checks out with these wires, chances are your MAF is bad and must be replaced. Check our How To DIY on replacing your Fiesta MAF for further instructions.

You now know how to Test a Ford Fiesta MAF using our DIY How To Guide. Have any questions about this guide? Leave them for us below!