How to Tell if a Mass Air Flow Sensor Is Bad

One of the mechanisms you will find in a vehicle’s electronic fuel injection system is the mass air flow sensor. This component measures how much air is admitted into the engine. Usually located between the air filter and the car’s engine within the intake air duct, the mass air flow sensor does its job, which is in turn used by the engine computer to gauge the correct quantity of fuel injected into the cylinders to produce the least emissions and the most combustion. It is not uncommon to have trouble with the mass air flow sensor. One problem is a bad or dirty mass air flow sensor. This can cause a vehicle to stall, usually when the car’s engine is cold, reduced acceleration, or misfiring, to name a few. Because of the several things this particular problem could lead to, it is always important to determine if your MAF is in proper working condition. By knowing how to detect the signs, you can determine how to get the component to work properly and avoid unfortunate incidents later on. Here are some ways you will be able to know if your mass air flow sensor has gone bad.

• Retrieve trouble codes from the vehicle’s computer. With a scanning device, get your car’s trouble codes from its computer. You may also ask any auto supply store to retrieve this code for you, in case you do not have the tools to do so. Many of these stores offer this service for free.
• Use a voltmeter. A voltmeter is a gadget that measures the potential voltage between two points in an electrical circuit. With your car running idle, measure your MAF sensor’s power output with this device. The initial reading you should see on the meter should be a voltage of about 2.5. Observe if this reading remains consistent after tapping the sensor with your finger. This voltage should go up smoothly as you try to increase the rpm of your car’s engine. If you notice that the voltage readings are irregular, then the MAF sensor is not producing the suitable signal.
• Examine your MAF sensor’s self-cleaning circuit relay. The engine computer of your car uses this relay to clean the wire of your MAF sensor. Once a relay that is responsible for a particular circuit has been damaged, the vehicle’s computer is no longer capable of cleaning the wire, which leaves it exposed to all sorts of impurities and dirt. When that happens, the MAF sensor is not able to perform its job properly. When in doubt about how to check your relay, always read through the service manual of your vehicle.

There are a number of benefits you can enjoy by using a perfectly conditioned mass air flow sensor, including an increase in the fuel efficiency of the car, a more reliable and much smoother engine reaction when making quick changes on the throttle, and better engine performance overall. By being able to recognize the signs of MAF sensor problems, you will also be able to best determine your course of action to find a solution and restore it to its fully operational state.