In a nutshell, a P0102: MAF Sensor Circuit Low Frequency tells you that the MAF sensor is stuck producing a low frequency signal.
In this tutorial, I'll go into detail what this trouble code means -all in plain English. I'll also talk about some of the tests you can perform to find its cause and solution.
Contents of this tutorial:
You can find this tutorial in Spanish here: Código P0102 ¿Qué Significa? (1996-1999 3.8L V6 Buick, Chevrolet, Pontiac, Olds) (at: autotecnico-online.com).
APPLIES TO: This tutorial, on the P0102 OBD II trouble code, applies to the following vehicles:
- 3.8L Buick LeSabre: 1996, 1997, 1998, 1999.
- 3.8L Buick Park Avenue: 1996, 1997, 1998, 1999.
- 3.8L Buick Regal: 1996, 1997, 1998, 1999.
- 3.8L Buick Riviera: 1996, 1997, 1998, 1999.
- 3.8L Chevrolet Lumina: 1998, 1999.
- 3.8L Chevrolet Monte Carlo: 1998, 1999.
- 3.8L Oldsmobile 88 (Eighty-Eight): 1996, 1997, 1998, 1999
- 3.8L Oldsmobile 98 (Ninety-Eight): 1996
- 3.8L Oldsmobile Intrigue: 1998, 1999
- 3.8L Oldsmobile LSS: 1996, 1997, 1998, 1999
- 3.8L Oldsmobile Regency: 1997, 1998
- 3.8L Pontiac Bonneville: 1996, 1997, 1998, 1999
- 3.8L Pontiac Grand Prix: 1997, 1998, 1999
What Does Trouble Code P0102 Mean?
A trouble code P0102: Mass Air Flow Sensor Circuit Low Frequency lets you know that the mass air flow sensor's signal frequency is stuck at a frequency of less than 1200 Hz for more than two seconds when the throttle plate angle is between 0 and 50%.
To better understand why this is a problem, take a look at the section: What Does The Mass Air Flow Sensor Do?
Common Symptoms Of A P0102 Trouble Code
The mass air flow sensor is a mission-critical component of the fuel injection system.
It is the principal sensor that the fuel injection computer uses to calculate the amount of air entering the engine.
As such, when it fails, engine performance will suffer. You'll see one or more of the following symptoms:
- Rough or low idle.
- Very high idle.
- Engine may start and stall.
- Little to no acceleration
What Does The Mass Air Flow Sensor Do?
The mass air flow sensor's job is to inform the fuel injection computer the amount of air entering the engine when it's running.
When the throttle plate is at rest (unopened) such as when the engine is idling, the signal frequency that the MAF sensor produces is low.
Now, as the throttle plate opens and the engine accelerates (which means more air is entering the engine), the mass air flow sensor signal frequency increases.
As the throttle plate closes and the engine returns to idle (due to the decrease in air entering the engine), the mass air flow sensor signal frequency decreases.
As long as the fuel injection computer sees the MAF signal frequency increasing/decreasing, it knows more/less air is entering the engine.
What Causes A P0102 Trouble Code?
The most common cause of a P0102 trouble code is a bad mass air flow sensor.
Other things that can cause a P0102 trouble code are:
- An open-circuit or short-circuit problem in the MAF signal wire between the MAF sensor and the fuel injection computer.
- A bad MAF sensor connector.
- Bad fuel injection computer (although very rare).
How To Diagnose And Repair A P0102 Trouble Code
Troubleshooting and resolving a trouble code P0102 involves testing the mass air flow sensor.
The test involves confirming, with a multimeter, that the mass air flow sensor's frequency signal is stuck at or below 1200 Hz as you open/close the throttle plate (with the engine running of course).
Then making sure that the mass air flow sensor is getting power and Ground from the fuel injection computer.
Now, if the MAF sensor test results confirm that the signal frequency DOES NOT increase as you open the throttle plate and that the sensor is getting power and Ground, then you can conclude that the sensor is bad and needs to be replaced.
You can find the MAF test explained in detail here: How To Test The MAF Sensor (GM 3.8L V6 1996-2005).
Where To Buy The MAF Sensor And Save
The following links will help you comparison shop MAF sensor trusted brands (no cheap knockoff parts that only last a few days):
25%Not sure if the above MAF sensor fits your particular vehicle? No worries, once you get to the site they'll ask you for the particulars of your vehicle and make sure it fits. If it doesn't fit, they'll find you the right one.
More 3.8L V6 GM Tutorials
You can find a complete list of 3.8L GM V6 tutorials in this index:
Here's a small sample of the tutorials you'll find in the index:
- How To Test The MAF Sensor (GM 3.8L V6 1996-2005).
- How To Test A Does Not Crank Condition -Case Study (GM 3.8L).
- GM 3.8L Ignition Control Module And Crank (3X, 18X) Sensor Test.
- How To Test The Ignition Coil Pack -Misfire Troubleshooting Tests (GM 3.8L).
If this info saved the day, buy me a beer!
