Free Auto Repair Advice by Professional Mechanics
How Does it Work /
Mass
Air Flow Sensor
Mass Air Flow Sensor
The mass air flow sensor (MAF) is used to monitor the
amount of air going into the engine while running. Mass air flow sensors work in
conjunction with the oxygen sensor and the engine control system to maximize
performance and economy. A vehicles mass air flow sensor delivers a signal to
the PCM (engine control module) telling the amount of air coming in, this is
compared with oxygen levels in the exhaust to determine the efficiency of the
engine. It is usually difficult to detect when a mass air flow sensor fails, the
"check engine light" or engine symbol will probably
not be illuminated. Your car, truck or SUV may have a poor idle quality, stall,
low power or all three. Your PCM may have no trouble codes
because the PCM cannot detect a problem since the sensor is working but is out
of range.
Mass Air Flow Sensor
What has occurred with most MAF failures is the sensing element or "hot wire"
that is used to give electronic feedback to the PCM for processing has become
contaminated by air particulates. The mass air flow sensor is reporting to the
PCM that less air is running through the engine than actually is. The PCM will
then lean the fuel mixture down to the point that it will cause performance
issues. There is not enough variance in the system to trigger a MIL "Check
Engine" light so this particular repair problem can be difficult to detect
through normal troubleshooting methods.
A mass air flow sensor is most common in newer vehicles,
this sensor is used to help maximize efficiency and reduce emissions. One of the
benefits of the mass air flow sensor is that it can respond to changes in
air intake flow. There are no moving parts in a mass
air flow sensor. Most vehicles mass air flow sensor locations are in the air
intake for the engine, this allows easy replacement. It is recommended that the
sensor be replaced approximately every 60,000 miles.
How Does it Work
/ Mass
Air Flow Sensor
Purchase Engine OBD2 Scanner
Check Manufacturer Specific Mass Air
Flow Sensor Questions and Answers
Related Subjects
GET AN ONLINE
REPAIR MANUAL
FOR YOUR CAR Get instant access to your vehicles drive belt routing, wiring diagrams,
trouble code information, updates and factory bulletins.
| 
