OBDII trouble code P0101 has to do with your mass air flow (MAF) sensor, and the code refers to the ECU receiving a signal from the MAF it’s not expecting. The specific verbiage of this error code is Mass or Volume Air Flow Circuit Range/
The mass air flow sensor in your 3.5 liter VQ35DE Nissan or Infiniti engine is mounted to the intake pipe, as part of your airbox. You can access the MAF plug by simply locating your intake pipe, the MAF adapter and sensor and unplugging the six pin connector.
Your trouble code P0101 can also have some company, with other OBDII trouble codes, such as P0174 or P0330. That’s why it’s a good idea to know how to test a VQ35 MAF when you have these types of errors.
Possible causes of P0101
- Intake leak
- Tear in intake snorkel
- Failed Mass Air Flow Sensor
- Problem in Harness
- Failed ECU
We’ll begin our how to test a VQ35 MAF by unplugging the MAF connector and referencing the diagram below.
Before we begin replacing our MAF, we’ll be testing the connector to make sure that your MAF is receiving power, ground and that your incorporated air intake temperature sensor and ambient temp sensors also receive power.
How To Test a VQ35 MAF
Begin testing your 3.5 liter MAF to resolve the P0101 OBDII trouble code, by using a multimeter to test the pins in question. If you are not familiar with a multimeter or voltmeter, use our guide to help you figure things out.
The first part of our DIY How To Test a VQ35 MAF guide will be testing the intake air temperature sensor, that’s part of your MAF. Begin by putting the black lead of your multimeter to the negative battery terminal, and use the red probe to gently test PIN 6, which should provide you a low refence ground signal.
Your VQ35 ECU provides ground to this circuit, and if you have grounds at this pin, move onto PIN 5. PIN 5 should be a switched 5 volt signal. Again this is the power wire for your Intake Air Temperature circuit.
Now we’ll begin testing our VQ35 MAF itself, by checking for power and ground at the MAF terminal. The next wire you’ll be checking is PIN 3 which is the ground wire or low reference for your mass air flow sensor. If you have ground here, the next wire to check is PIN 2 which is switched 12 volt power for your MAF. If you do not have these values at these wires or terminals, remember to have your G35 or 350Z turned to the “ON” position while testing.
The final wire for your MAF is PIN 4 which is the MAF signal wire. This wire sends the KARMAN or MAF wire voltage to your ECU, which will then turn that frequency or voltage to the corresponding air volume, which will help the ECU operate your engine. You can opt to test this wire for the correct signal, but chances are if you have power and ground at the terminals listed above, you will require a replacement MAF for your VQ35.
How To Replace your VQ35 MAF
Replacing your MAF is a simple and straightforward process that can be completed by any shadetree mechanic. Undo the 10mm bolts that secure the airbox and the intake air piping to the chassis of your VQ.
Make sure to check the accordion like snorkel that connects the upper plastic intake plenum to the outlet of your MAF adapter or housing. This accordion intake piece can easily become ripped or suffer an intake leak. Because this leak would be located AFTER your MAF, this is unmetered air that is causing your VQ35 to run lean or have the P0101 OBDII trouble code.
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