Your Evolution MAF Sensor in your 4G63 powered Mitsubishi is what your ECU uses to provide the right amount of fuel to your 2.0 liter engine. Mounted to your air intake box with four 10mm bolts, this Karman sensor analyzes the incoming air volume. This air charge is used as the basis for your engine operation.
Today I’ll be showing you how to test the mass air flow meter in a 2006 Mitsubishi Evolution MR. There is a failing Evolution MAF Sensor in this 4G63, and we’ll be using a digital multimeter to test the operation of this airflow meter.
This vehicle belongs to a customer equipped with several modifications, including an aftermarket MAF intake kit. This makes testing the Evolution MAF Sensor significantly easier on this particular vehicle. However if you happen to own a stock or factory Evolution, you’ll need to disconnect the MAF from under your airbox.
Whichever way you unplug your Evolution MAF Sensor, just depress the locking tab. Now you’ll have to get into the driver seat and turn the ignition to the “ON” position. This enables the 4G63 sensors to be powered up, and from here you’ll use the multimeter to test for function.
Symptoms of a bad Evolution MAF Sensor
There are many symptoms but one of the first warning signs is your Mitsubishi check engine light. When this is Malfunction Indicator Lamp is turned on in your instrument cluster, it’s an early sign that something is wrong.
- Bad gas mileage
- Boost won’t build
- Sluggish performance
- Check Engine Light ON
Use an OBDII scan tool to check and retrieve the code in question. If it comes up as a MAF sensor related check engine code, this guide will help.
Testing the Evolution MAF Sensor for Power
The mass air flow meter in your Mitsubishi is a 7 pin unit that also houses your Intake Air Temperature sensor. Because of this there’s several wires that you will be checking, first of which will be for power. To do this you will need to unplug your MAF sensor, and place the red lead of your multimeter gently to the metal pin inside the metal connector.
Now put the black lead of the device to the negative terminal in your battery. The first wire to check is PIN 4 and this wire should be 12 volts straight from the ECU. Once you’ve confirmed this wire, the next pin to check is PIN 7, which should return 5 volts of DC power with the key turned to the “ON” position.
The next wire to check is PIN 2, which should show a DC voltage between 4.6 volts and 4.9 volts of DC signal. If you see this signal the next set of wires to check is the low reference ground signal.
Now reverse the digital multimeter leads, and check for ground at PIN 3. This should be a ground wire, which will show you that the Evolution MAF Sensor is getting power and ground.
Testing the Evolution MAF Sensor Signal
If you have power and ground at your mass air flow sensor, the last step is to check the airflow signal wire, which is PIN 5. However to test this you’ll need to plug the harness back into the MAF and start your engine. Because of the MAF sensor’s proximity to the cooling fans, it’s best to do this with either a wire extension or a wire piercing tool.
You can also trace this wire back, and it should be a GRAY wire with a RED stripe. By using a capable reader, you should be able to read the karman values directly from your MAF sensor. The readings aren’t quite as important as your Evolution MAF Sensor ability to smoothly sweep up in voltage to match the engine speed.
If you see any gaps, spikes or other issues with voltage, you’ll need a replacement Evolution MAF Sensor.
This is of couse assuming that your digital multimeter has the capability to read Hz. If it doesn’t you can opt to stick to the DC voltage and test how your Evolution MAF Sensor reacts. You can also do this through your OBDII scan tool and by reading the Live Data feeds from your MAF sensor.
Replacing your Evolution MAF Sensor is easy to do by removing the 10mm bolts that connect to your air filter or airbox. Have any questions about this Evolution MAF Sensor guide? or want to learn more about the 4G63 engine or the Mitsubishi mass air flow meter? Subscribe for all the latest tech tips, How To Guides and tutorials.
I have found that this article’s Air Flow Meter “pin out” is in direct conflict with the official Mitsubishi factory configuration of the 7 pin jack (B105)….looking at the wiring harness jack from the end as shown in the article, the “pin out” should read 1 thru 7 from right to left NOT left to right….the #1 terminal is therefore on the right and #7 terminal is on the left of the B105 connector.