When you experience problems with your GMC Yukon MAF, your mass air flow sensor could be going bad or there may be another issue causing an issue. When this happens, your check engine light will illuminate on your GMC dashboard, and you’ll need to use a scan tool to retrieve the OBDII code.
The OBDII check engine trouble code P0101 refers to a problem with your mass air flow sensor in your GMC Yukon. The specific language for this trouble code is Mass Air Flow Sensor Performance. This trouble code can come from a variety of different causes, such as loss of operation from your MAF, or an intermittent wiring problem.
Today we’ll be showing you how to test your GMC Yukon MAF in a 2015 GMC Yukon XL. This is one of the newer style GMC trucks, and the MAF incorporates the use of an Intake Air Temperature sensor.
The mass air flow sensor in your Yukon is there to tell your PCM all about the air that’s heading into your engine. Using this data, your PCM can then control and deliver the right amount of fuel and spark to operate your engine. When your mass air flow sensor isn’t working right, your engine will run roughly, idle poorly and could get horrible gas mileage.
When the dreaded OBDII P0101 becomes a problem in your GMC, try to clean the air filter before attempting to do anything else. You can get a scan tool or even rent one from your local auto parts store. Use it to clear and erase the stored code in your PCM, and then clean the air filter element thoroughly.
Many times your air filter can become clogged, preventing the right amount of air flow to reach your hotwire mass air flow sensor. When this occurs your PCM thinks that your MAF is at fault, and thus triggers your code. Clear the code and see if your cleaner air filter fixes your problem.
If your check engine trouble code has not gone away, chances are you have an issue with your MAF.In the 2015 model year, the GMC Yukon MAF is a hot wire style of sensor. As previously stated, this MAF in question combines Manifold Absolute Pressure (MAP) sensors with the Intake Air Temperature (IAT) sensor and refers to the engine speed to provide the correct speed density value.
How To Test GMC Yukon MAF
Before you begin this DIY guide on testing your Yukon MAF, you will need an multimeter to properly test the power and ground circuits of your mass air flow sensor. If you are not sure what a multimeter is, or how to use one, try our quick guide here. Once you are ready to test your MAF, locate the wiring connector that’s secured by way of a red locking tab.
Pull up on this red locking tab and then disconnect your MAF and flip the wiring connector to face towards yourself. The actual mass air flow sensor in your Yukon is secured by two hex screws as shown below. But you won’t be testing the MAF itself, instead you will be testing the wiring harness you just disconnected.
You will be using your multimeter to test the wiring of your Yukon MAF, by measuring for power and ground at the wires we’ll be showing you. Because the 2015 GMC MAF is a hot wire style, we only care about power and ground in this testing scenario.
Why is that you may ask? It has a lot to do with how a hot wire MAF works. Because this is a hotwire style of sensor, the way the MAF works is that your GMC Yukon powers the wires internal to the device. These wires are the air flow sensing elements inside your hotwire MAF, and the way your PCM “reads” the incoming air is to determine how much these wires are being cooled.
If the MAF sensor requires more current to keep the wires hot, this signifies a greater amount of incoming airflow. This frequency is used by your Yukon PCM to calculate the airflow based on the signal sent by the MAF.
How To Test for Power
Take the black probe of your multimeter and connect to the negative terminal of your Yukon battery. The wire you will be testing for power is both PIN 2 as well as PIN 6 shown below in the diagram and labeled as 1.
You should have 5 volts of power at either of these two wires, and this combination ensures that your IAT sensor is working as well. The next step in testing the MAF is to measure for a low reference ground signal.
The ground wires for your Yukon are PIN 5 and PIN 7, labeled in the diagram above as the number 2. Switch your probes on your multimeter and measure for ground at these wires. When testing your MAF connector, never push or shove the multimeter probe into the front of the connector.
This can cause severe damage and even crack or cause the internal pins from not making contact. You don’t want this to happen to your Yukon. Instead use the tip of the probe and gently touch the metal pin internal to the MAF connector to measure for power and ground.
If these wires do not return the power and ground you are looking for, chances are you have a blown fuse or another underlying issue. Try to trace back your wires and check for any areas of the wire that’s exposed or may be rotting from the inside out. Cut away the damaged segments and repair to restore the normal operation of your mass air flow sensor.
To replace your Yukon MAF, make sure you get the right one for your 6.2 liter Flex Fuel GMC Truck. Install your new MAF by unscrewing the hex bolts and removing the bad MAF in question.
Use your scan tool to clear your OBDII P0101 trouble code, and you should be good to go! You have now learned how to fix a OBDII P0101 check engine code in your GMC! Have any questions about our guide? Leave them for us below and let us know!