Check Engine Light

[Greggo63]

P0101 (MAF) Mass Air Flow or (VAF) Volume Air Flow Sensor Circuit Range/Performance Problem

I’ve been getting this code, I changed the sensor and checked connections and wiring!
I’m stumped!

 

[Doubeleive]

be sure the intake & pcv system assembly is properly installed from filter housing to throttle body (no gaps or any way for outside air to enter) if that is all good then you either have a bad new maf or bought a cheapo re-pop or there is a wiring short, you can try jiggling the harness with the vehicle running and see if it triggers the code.

 

[PNWYukon]

DTC P0101 Mass Air Flow (MAF) Sensor Performance

CONDITIONS FOR RUNNING THE DTC

• DTCs P0068, P0102, P0103, P0106, P0107, P0108, P0120, P0220, P0442, P0443, P0446, P0449, P0452, P0453, P0455, P0496, P2135 are not set.
• The engine is cranking or running.
• The ignition 1 signal is between 11-18 volts .
• The throttle position (TP) indicated angle is less than 95 percent .
• The change in the TP indicated angle is less than 5 percent .
• The MAP sensor is less than 80 kPa .
• The change in the MAP sensor is less than 3 kPa .
• The above conditions are met for 1.5 seconds .
• DTC P0101 runs continuously when the above conditions are met.

CONDITIONS FOR SETTING THE DTC
The PCM detects that the actual MAF sensor frequency signal is not within a predetermined range of the calculated MAF value for more than 4 seconds .

DIAGNOSTIC AIDS

• Inspect the harness of the MAF sensor 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 at idle or during deceleration may cause this DTC to set. Inspect for any vacuum leak downstream of the MAF sensor.
• Inspect for any contamination or debris on the sensing elements of the MAF sensor.
• Inspect the air induction system for any water intrusion. Any water that reaches the MAF sensor will skew the sensor and may cause this DTC to set.
• A wide open throttle acceleration from a stop should cause the MAF sensor parameter on the scan tool to increase rapidly. This increase should be from 3-10 g/s at idle to 170 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.
• A high resistance of 15 ohms or more on the ignition 1 voltage circuit may cause this DTC to set. A high resistance may cause a driveability concern before this DTC sets.
• The barometric pressure (BARO) that is used to calculate the predicted mass air flow value is initially based on the MAP sensor at key ON. When the engine is running the BARO value is continually updated near wide open throttle. A skewed MAP sensor will cause the calculated mass air flow value to be inaccurate and may result in a no start condition. The value shown for the MAP sensor parameter varies with the altitude. With the ignition ON and the engine OFF, 101 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 5-volt reference circuit of the MAP sensor may cause this DTC to set.
• A high resistance on the low reference circuit of the MAP sensor may cause this DTC to set

 

[nofaz]

I've been noticing a rough idle for just a minute or so at startup. Slight hesitation during cold acceleration and now I'm getting the P0101 code intermittently. I've erased the code 3 times and each time it comes back in less time. Just drove (2 days ago) 400 mile round trip. All was well on the way out but at my 1st stop on the way back the code set upon restarting the vehicle. I've read somewhere long ago and far away that cleaning the detecting element in the MAF sensor is a legitimate 'try' for repair. Worth my time or just order a new one? I'll make the checks suggested in the list but I have my doubts. 137k miles.

 

[nofaz]

2013 GMC Yukon Denali

 

[nofaz]

Removed the MAF sensor today and discovered it was very coated on the inlet side and bare metal on the down stream side. I tried some compressed air from a computer duster but no joy.
Next I tried some rubbing alcohol in a pump sprayer. Again, no joy. Next I took the computer duster to clean off the alcohol. I bumped the small sensor wire with the plastic tip of the computer duster and the dark coating came off. I continued to 'rub' the coating off of both sensor loops until the bare metal was exposed on both elements. I blew off any residue with the computer duster and reinstalled the sensor. Attached are two pictures of the sensor prior to my cleaning. Wishing now I would have taken a picture of the cleaned sensor. Performance has improved and after 3 separate trips today the code has not reappeared. I've ordered a new GM sensor from Rock Auto, not trusting this simple repair.

 

[nofaz]

New MAF sensor showed up yesterday. A day early to boot! Installed it when I got home from work. Ran some errands in the evening and I am definitely noticing improved acceleration when leaving from a stop. Also less hesitation on acceleration. Pleased with the results and happy that I didn't just stick with the old sensor after cleaning it solved the P0101 problem.