P0102 is a very common trouble code in the Toyota Sequoia. It means the the Mass Air Flow (MAF) circuit is low, and that it is not performing within its specified operating range.
We will cover exactly what that means and potential fixes for it below. It should be considered a high priority to fix, as the MAF sensor not reading properly can really make an impact on the performance of the vehicle.
It’s important to understand what the MAF sensor does. It measures the air density and volume between the air filter and the intake manifold. The engine’s computer uses this reading to determine the exact amount of fuel that the engine needs for optimal combustion. When it is not getting the proper reading, it can really cause some issues with your Sequoia.
Related: Toyota Sequoia P0101 Diagnosis: MAF Sensor
P0102 Symptoms: Toyota Sequoia
Since P0102 has to do with the Mass Airflow Sensor, which is a huge part of the Sequoia’s engine combustion process metering, it is going to cause noticeable symptoms.
Usually, one or more of these symptoms will occur, but it’s not uncommon to have no symptoms other than the check engine light.
P102 symptoms include:
- Service engine soon light
- Poor idle
- Stalling
- Hard starts
- Poor performance
- Improper air/fuel mixture
Toyota Sequoia P0102 Causes
Here are the most common causes of P0102 in the Toyota Sequoia. They are presented loosely in order from most to least likely:
- MAF Sensor Dirty– Over the course of its life, the MAF sensor will often get so covered in grime that it’ll no longer get an accurate reading. They can be cleaned, but it’s easy to mess one up, and you don’t want to use a wire brush. Here’s a great article on exactly how to clean one from Family Handyman. MAF Sensor Cleaning
- MAF Sensor Failure– While it is very likely that the MAF sensor itself could be the problem, it’s absolutely necessary to test it before you replace it. Here’s a video on how to test one without pulling it. This is important for two reasons. The first is that they are expensive. The second is that it only takes a few minutes to test it with a multimeter. If you do need one, they are pretty reasonable on Amazon. Just make sure you check to make sure it fits your year Sequoia before purchasing.
- Intake Manifold/Vacuum Leak– If there is a leak in the intake manifold, it will be impossible for the MAF sensor to get an accurate reading. Without knowing how much air is really getting into the engine, P0102 will be thrown.
- MAF Sensor Wiring– Make sure to check around the MAF sensor for opens or shorts. Start by inspecting the wiring harness for obvious damage. If you don’t see any you can use a multimeter to test the wiring. At this point if you use the YouTube video above in the MAF sensor dirty section, and there turns out to be no voltage at all, try checking out How to Find an Electrical Short on Most Any Vehicle from BackYardMechanic
- Clogged Catalytic Converter– If you are getting P0102 in your Sequoia accompanied by a noticeable lack in power at speed, it may very well be that you have a clogged catalytic converter
Conclusion
Whatever the reason for P0102 in your Toyota Sequoia, ignoring it is a bad idea. Good luck figuring it out, and if there is anything you’d like to ad, please leave a comment below!