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How Does it Work /
Mass
Air Flow Sensor
Mass Air Flow Sensor
The
mass air flow sensor works in conjunction with the
oxygen sensor and the
engine control system. While the oxygen sensor determines the oxygen levels
in the exhaust system, the mass air flow sensor is used to monitor the amount of
air passing through the engine while running. A vehicles mass air flow sensor delivers
a signal to the ECM (engine
control module). 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 ECM can not detect a problem.
Mass Air Flow Sensor
What has occurred is the sensing element or "hot wire" that is used to give electronic
feedback to the ECM for processing has become contaminated by air partials. The
mass air flow sensor is reporting to the ECM that less air is running through the
engine than actually is. The ECM will then lean the fuel mixture down to the point
of run ability problems. There is not enough variance in the system to trigger a
MIL (malfunction indicator light) - "Check
Engine" light so this particular repair problem can be difficult to detect through
normal trouble shooting 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 vary
responding 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
Check Manufacturer Specific Mass Air
Flow Sensor Questions and Answers
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