You can easily and quickly test the mass airflow (MAF) sensor with a multimeter on the 3.4L V6 Chevrolet and Pontiac vehicles.
In this tutorial, I'll explain the three tests you'll need to perform to find out if it's bad or not. All of which are described in a step-by-step manner.
If you need to just clean the MAF sensor, this tutorial will help: How To Clean The GM Mass Air Flow (MAF) Sensor.
NOTE: This is an ON CAR test -no need to remove the MAF sensor from its place to test it.
Contents of this tutorial:
- Common Symptoms Of A Bad MAF Sensor.
- What Tools Do I Need?
- Circuit Descriptions Of The MAF Sensor Connector.
- Where To Buy The MAF Sensor And Save.
- How Does The MAF Sensor Work?
- TEST 1: Making Sure The MAF Sensor Is Getting 12 Volts.
- TEST 2: Making Sure The MAF Sensor Is Getting Ground.
- TEST 3: Testing The MAF Signal With A Multimeter.
- More 3.4L V6 Chevrolet, Pontiac Tutorials.
APPLIES TO: This tutorial applies to the following vehicles:
- 3.4L V6 Chevrolet Impala: 2000, 2001, 2002, 2003, 2004, 2005.
- 3.4L V6 Chevrolet Lumina Minivan: 1996.
- 3.4L V6 Chevrolet Monte Carlo: 2000, 2001, 2002, 2003, 2004, 2005.
- 3.4L V6 Chevrolet Venture: 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005.
- 3.4L V6 Pontiac Aztek: 2001, 2002, 2003, 2004, 2005.
- 3.4L V6 Pontiac Grand Am: 1999, 2000, 2001, 2002, 2003, 2004, 2005.
- 3.4L V6 Pontiac Montana: 1999, 2000, 2001, 2002, 2003, 2004, 2005.
- 3.4L V6 Pontiac Trans Sport: 1996, 1997, 1998.
Other MAF sensor test tutorials:
- How To Test The GM MAF Sensor (3.1L, 3.4L, 4.3L, 5.0L And 5.7L)
- How To Test The MAF Sensor (GM 3.8L V6 1996-2005)
- How To Test The MAF Sensor (GM 4.8L, 5.3L, 6.0L, 8.1L)
- How To Test The GM MAF Sensor Express And Savana Van (2003-2008)
Common Symptoms Of A Bad MAF Sensor
The fuel injection computer needs to know how much air is entering the engine as it runs, and the one tasked with this job is the MAF sensor.
So when this bad boy fails, engine performance and driveability will suffer. The fuel injection computer will set one of the following diagnostic trouble codes:
- P0101: MAF Sensor Performance Problem.
- P0102: MAF Sensor Circuit Low Frequency Signal.
- P0103: MAF Sensor Circuit High Frequency Signal.
You'll also see one or more of the following symptoms:
- Check engine light illuminated on your instrument cluster.
- Lack of power when accelerating the engine/vehicle.
- Black smoke coming out of the tailpipe.
- Bad gas mileage.
- Engine idles rough.
- Engine starts but immediately stalls.
- Extended engine cranking. In other words, you've got to crank the engine a long time for it start.
What Tools Do I Need?
Although you don't need any expensive or exotic diagnostic test equipment to test the MAF sensor, you will need a few things.
Here's what you'll need:
- A multimeter that can read Hertz frequency. If you don't have one and would like to buy one, check out my recommendations here: Buying A Digital Multimeter For Automotive Diagnostic Testing.
- A wire piercing probe or a back probe to be able to access the signal within the MAF sensor's output signal wire. To see what this tool looks like, click here: Wire Piercing Probe.
- Although not an absolute must, a code reader or a scan tool to be able to extract any codes registered in the fuel injection computer's memory.
As you can see, there's nothing in the list above that will break the bank!
Circuit Descriptions Of The MAF Sensor Connector
The mass airflow sensor is a simple three-wire component that needs 12 Volts and Ground to produce its output signal.
To successfully test the MAF sensor, we need to know what each wire does. So, here's a brief description of each:
|A||Yellow (YEL)||MAF Signal|
|B||Black with white stripe (BLK/WHT) or Black (BLK)||Ground|
|C||Pink with black stripe (PNK/BLK) or Pink (PNK)||12 Volts DC|
To test the MAF signal circuit, I recommend you use a wire-piercing probe or a back probe. You can see what this tool looks like here: Wire Piercing Probe.
IMPORTANT: All of the tests are ON CAR TESTS, do not remove the mass airflow sensor from the vehicle or its plumbing.
Where To Buy The MAF Sensor And Save
The following links will help you to comparison shop for a known automotive name-brand MAF sensor (no knock-offs) for your 3.4L V6 Chevrolet or Pontiac vehicle:
How Does The MAF Sensor Work?
The mass airflow sensor can measure the amount of air flowing past it and send that information to the fuel injection computer.
Here are some more specific details:
- When you turn the key, 12 Volts are provided to the MAF sensor by the wire labeled with the letter C (see photo above).
- The wire labeled with the letter B provides Ground.
- Once the engine starts and air flows through the MAF sensor, the wire labeled with the letter A carries the frequency signal (that the MAF sensor creates) to the fuel injection computer.
- When engine RPMs increase, like when you step on the accelerator pedal, the MAF Hertz frequency signal increases.
- When you step off the accelerator pedal, and engine RPM decreases, the MAF Hertz signal decreases.
When the MAF sensor fails, it'll usually always stay stuck, producing a single Hertz frequency value or none at all when engine RPMs increase or decrease.
You can find out more about the MAF sensor here: What Does The MAF Sensor Do? (3.4L V6 Chevrolet, Pontiac).