Mass air flow sensor
Mass Airflow Sensor cleaning is very straight forward, simply soak the end of the cotton buds and wipe the wires. Brake Cleaner which does not damage plastics can also be used. To show how dirty the Mass Airflow Sensor was, the lower wire is cleaned the top is not.Īcetone does not leave any residue behind when it dries and it does not effect electrical components so it is perfect for this use. In this case the wires were completely black, it was a surprise the engine ran at all! This sensor had been on the car for over 200,000 miles. Once you have the 2 pieces seperted you can see the 2 wires that make up the MAF sensor unit. On the G20/ Primera the Mass Air flow Sensor looked to be glued to the tube section/housing, so a flat head screwdriver was needed to prise apart the two components. Once the screws were removed the sensor housing itself had to be pried away from the housing. The head of the screws where severely corroded so a pair of pliers were necessary to remove them. In this case it was located with 2 screws. Once you have removed the section of the intake that holds the Mass Airflow Sensor you have to remove the sensor from the housing. When you have found it, remove the section of plastic that contains the sensor itself. Before the throttle body on normally aspirated cars and before the turbo (usually) on uh, turbo cars. It is located somewhere in the engine’s intake system. The location will vary depending on your car but it is usually pretty obvious where it is. In this photo the sensor is old and the screws which hold the MAF sensor unit in the main housing had corroded. We need to remove the sensor itself from the housing. Also, the problem may point to a bad self-cleaning circuit or relay.The Mass Airflow Sensor is usually enclosed in a hard plastic housing.
#Mass air flow sensor manual
Consult your vehicle repair manual for the correct specification for your particular vehicle model. The MAF sensor’s output should be about 30 hertz (Hz).See your meter user’s manual, if necessary, to connect the red lead to the correct jack on your meter. Plug in the MAF sensor’s electrical connector.Photo courtesy of Antonín Ryska on Wikimedia. Output signals from a hot-wire (red) and hot-film (black) type MAF sensors. If there’s no output response from the sensor, replace it.If dirt or contamination is the problem, this may suggest a bad self-cleaning circuit or relay. If the reading becomes erratic or output voltage seems slow, the hot-wire or sensing element may be dirty or contaminated.The sensor’s output signal should increase smoothly between 1.5 and 3.0 volts. If it fluctuates or the engine misfires or surges, there could be loose electrical connections inside the sensor and needs to be replaced.
On some models, this initial voltage at idle may be higher. Your meter should register 0.5 to 0.7 volts.Engage the parking brake and set your transmission to Park (automatic) or Neutral (manual).Make sure the meter’s leads are away from moving engine components.Backprobe the sensor’s signal (+) wire with your meter’s red lead, and the ground (-) wire with your meter’s black lead.Plug in the MAF sensor’s electrical connector.Turn the ignition switch to the Off position.