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Master
1,986 Answers
- Posted on Nov 11, 2009
Re: I got a check engine light and now it's gone. Code...
Mass Air Flow (MAF) Circuit Range/Performance Problem
The simplest thing to do is to reset the code and see if it comes back. Then
start with the cheapest, easiest repair procedures:
- Inspect for the following conditions:
An incorrectly routed harness--Inspect the harness of the MAF sensor in order
to verify that it is not routed too close to the following components:
- The secondary ignition wires or coils
- Any solenoids
- Any relays
- Any motors
- A low minimum air rate through the sensor bore may cause this DTC to set
at idle or during deceleration. Inspect for any vacuum leaks downstream
of the MAF sensor.
- A wide open throttle (WOT) acceleration from a stop should cause the MAF
sensor g/s display on the scan tool to increase rapidly. This increase
should be from 6-12 g/s at idle to 230 g/s or more at the time of the
1-2 shift.
If the increase is not observed, inspect for a restriction in the induction
system or the exhaust system.
- The barometric pressure (BARO) that is used in order to calculate the predicted
MAF value is initially based on the MAP sensor
at key ON.
- When the engine is running the MAP sensor
value is continually updated near WOT. A skewed MAP sensor will cause the
calculated MAF value to be inaccurate. The value shown for the MAP sensor
display varies with the altitude. With the ignition ON and the engine OFF,
103 kPa is the approximate value near sea level. This value will decrease
by approximately 3 kPa for every 305 meters (1,000 feet) of altitude.
- A high resistance on the ground circuit of the MAP
sensor can cause this DTC to set.
- Any loss of vacuum to the MAP sensor can cause this DTC to set.
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