Unfortunately, fault codes are a normal part of owning a car. In a perfect world we wouldn’t have codes, but all cars and engines are prone to the occasional fault. An engine fault code – or code for short – is more formally known as a diagnostic trouble code (DTC). P0102 code is a common DTC for many different vehicles. In this guide, we discuss the meaning, symptoms, causes, and fixes for DTC P0102.
P0102 – Mass or Circuit Airflow (MAF) Circuit Low Voltage Input
This code applies to any vehicles equipped with a mass airflow (MAF) sensor. The mass airflow sensor measures the volume and density of air entering the engine. Some MAF sensors also measure the intake air temperature (IAT). The sensor is often located after the air intake and before the throttle body. DTC P0102 indicates the MAF is reading a low airflow value. There are a number of different symptoms, causes, and potential fixes for this fault.
Common Associated Codes
- P0100 – MAF Circuit Malfunction
- P0101 – MAF Circuit Range/Performance
- P0103 – MAF Circuit High
- P0104 – MAF Circuit Intermittent
Also look for other codes present, especially things along the lines of O2 sensors, misfires, and air-fuel ratios. When airflow entering the engine is low it can affect air-fuel ratios (AFR’s). In turn, this may lead to fault codes related to the O2 sensors or AFR. Additionally, low airflow can cause misfires.
Depending on the exact issue at hand there are a number of potential symptoms. Look for the following signs if you experience DTC P0102:
- Check engine light (CEL / MIL)
- Rough engine operation (rough idle, hiccups/stuttering)
- Engine stalling
- Long cranking / issues starting
- Poor performance (reduced power)
Once DTC P0102 is detected by the cars computer (PCM, ECM, ECU) it should also trigger the check engine light. Some manufacturers refer to this as the malfunction indicator lamp. Other symptoms can vary quite a bit depending on the actual issue causing the code.
If it’s a sensor or circuit error then airflow entering the engine is likely normal and the signal just isn’t reading correctly. In these cases, you may not have other symptoms of P0102 code or they may be minor.
However, if air-flow is actually low then you’ll likely notice worse symptoms. The severity of symptoms depend on how much airflow is lacking. With significantly reduced air-flow you can notice extreme symptoms like engine stalling, long cranking, or no start. Otherwise, look for rough engine operation and poor overall performance.
How Serious Is Fault Code P0102?
Severity Rating: Low to Moderate
P0102 generally is not a serious issue that puts the engine or occupants at risk. As long as symptoms aren’t severe this issue should not cause the need to tow the vehicle or pull over immediately. However, if P0102 code comes with major symptoms then use your own judgement and err on the side of caution.
Stalling or other severe performance issues can pose a safety risk. You likely don’t want to stall in the middle of the freeway. A serious lack of power can also pose danger. Again, these symptoms generally mean the engine has a major lack of airflow. It’s less common than most other causes, so most won’t experience this.
Regardless of the severity of symptoms, it’s still a good idea to track down the cause and fix the problem as soon as possible. Symptoms and issues may become worse if you don’t address DTC P0102 in a timely manner.
Common causes of P0102 include:
- Dirty air filter
- Intake hoses loose or cracked
- Dirty MAF sensor
- Faulty MAF sensor
- Circuit problems
The actual issue at hand often relates to the MAF sensor itself or a signal error. However, don’t forget to consider some of the basics. If airflow is actually low then it may be a dirty air filter or issue with intake piping. Intake piping can be a common cause on turbo engines when a boost leak is present. This will usually be accompanied by a low boost code, such as 30FF.
In this section we will discuss diagnosing fault code P0102 when it’s the only code present. We will also cover diagnostics below for other codes present. Anyways, to diagnose DTC P0102 start with the following:
- Use a code reader to clear the check engine light and fault code. Test drive for about 15-30 minutes. If the code comes back then it’s time to diagnose the issue at hand
- Check the basics. Is the air filter or airbox dirty? It may be time to replace the filter or clean it. Also check that any accessible intake piping is intact and securely attached
- Next move onto the MAF sensor itself. Check the connection and wiring. If all looks in order then remove the MAF sensor.
- Clean MAF sensor and re-install. Clear DTC P0102 and test drive to see if the code comes back.
- If so, you may need to replace the MAF sensor or there may be another signal or circuit issue. Reference the below video
Occasionally engines have minor hiccups that trigger fault codes. As such, it’s always a good idea to try deleting the code and test driving to see if it comes back. If not, then you may not have any actual pressing issues that need fixing. Don’t forget the basics. If your air filter or air box are dirty that may affect airflow enough to trigger P0102.
MAF sensors often get dirty and gunked up with age and mileage. Cleaning the MAF sensor is a step that often works, so try using some mass airflow sensor cleaner. If this doesn’t work you may need a new sensor or there might be another issue at hand. The above video is a helpful resource to actually test the sensor grounds.
Other Fault Codes Present
It’s impossible to break down all of the steps since it can vary depending on any other codes present. Diagnosing P0102 code with others present may require a bit of ingenuity. Could the codes be related in any way? If so, start with that code as it may point you in a better direction. For example, if you have a 30FF low boost code then the issue at hand may be related to the turbocharger system.
Fix & Repairs
Talking about how to fix P0102 code may be a bit repetitive with the above. Following those steps should help track down the issue and point towards the necessary fix. The main purpose of this section is to touch on some basic concepts. If you can’t track down a simple fix and aren’t confident or mechanically inclined to proceed then a repair shop may be the best bet.
It sucks to spend extra on labor, but it could help save money. Costs may add up if you attempt to DIY the repair and end up replacing parts that aren’t the actual issue. We do think checking the basics and at least cleaning the MAF sensor are good steps. Just about anyone can accomplish this in their driveway, and chances are these easy fixes solve the problem.
P0102 Repair Cost
Repair costs for DTC P0102 can also vary quite a bit dependent upon the actual problem. Below are some ballpark costs for the common fixes:
- MAF Cleaning: $0-20
- MAF Replacement: $40-300+
- Air filter: $0-50
- Electrical issue: $0-200+
If you have the right products then you may be able to clean the MAF sensor virtually for free. Otherwise, buying MAF cleaner products can run about $10-20. The sensor itself will usually cost about $40-150. It’s a simple replacement most can likely do at home, but if you end up at a mechanic you may shell out $50-150+ for diagnostics and labor.
Otherwise, cleaning the air filter may mitigate P0102 code. Some filters aren’t cleanable, so you might have to buy a new filter. These often cost about $10-20, but can be more expensive for some vehicles. Lastly, electrical issues can sometimes be tough to track down and lead to expensive costs, but it’s cheap if you’re able to DIY the fix. You can also check our post on symptoms, causes and repair methods of code P1014 .
DTC P0102 FAQ’s
Much of this information is likely duplicate with the above topics in the article. However, we’ll list a few frequent questions regarding DTC P0102 as an easy resource.
What Does Fault Code P0102 Mean?
P0102 refers to Mass or Circuit Airflow (MAF) Circuit Low Voltage Input. The MAF sensor reads the volume and density of airflow entering the engine. If airflow is low or their is a sensor/signal error then it will trigger DTC P0102.
How Do I Fix P0102?
The fix for P0102 code is usually something as simple as cleaning the MAF sensor or the air intake. It’s a good idea to start with these basics as cleaning the air filter and mass airflow sensor are cheap and easy. Otherwise, you may need to replace the MAF sensor or track down electrical/wiring issues.
What Causes a P0102 Code?
Primary causes of P0102 are a lack of airflow into the engine or a mass airflow (MAF) sensor signal error.