P0101-Please help

[jah81592]

I have a guy with a Duramax who is from out of town. Went to the dealer and had the vehicle updated. The biggest problem is the truck was flashed from someone else before. It doesn't have a particulate filter and employs a 5" exhaust and K&N cold air intake. After turning off the egr and particulate switches we are getting a p0101. Unfortunately I am not a Diesel guru so I need help with this one. Anyone know what I need to do to get this corrected? I have attached the file. The truck is a 2008 Duramax with an Allison tranny. Attached is the tunefile.

[mecanicman]

Oil from the k and n filter can contaminate the maf. Try cleaning with nonclorinated brake clean or alcohol with qtip. Be careful/gentle. I dont know if your tune is big enough, but log your maf and make sure you are not pegging it.

[jah81592]

Cleaned the MAF and the p0101 code is always set at an idle, I appreciate the information. More ideas and suggestions? I am very open.

[mecanicman]

Dont know if it will help, but my only other suggestion is try playing with the clocking of the sensor. The k&n system will have changed the airflow through it, maybe changing clocking will bring it closer?

[jah81592]

new update-replaced the maf drove 20 miles at idle the reduced engine power light came on and the dreaded p0101 code back in effect. Back to the drawing board, does anyone know what actually sets this code with a diesel?

[mecanicman]

DTC P0101
Circuit Description
The mass air flow (MAF) sensor is an air flow meter that measures the amount of air entering the engine. The engine control module (ECM) uses the MAF sensor voltage signal to provide the correct fuel delivery for a reduction in emissions. The ECM uses the MAF sensor signal to control fuel delivery until a calibrated amount of engine air flow is attained. The MAF sensor has an ignition 1 voltage circuit, a signal circuit and a low reference circuit. The MAF sensor produces an output voltage based on the inlet air flow through the air induction system. This output voltage will display on the scan tool as a voltage parameter and as a grams per second (g/s) parameter. The ECM will calculate a predicted MAF value. The ECM compares the actual MAF sensor voltage signal to the predicted MAF value. This comparison will determine if the signal is stuck, or is too low or too high for a given operating condition. If the ECM detects that the actual MAF sensor voltage signal is not within a predetermined range of the calculated MAF value, DTC P0101 sets.

DTC Descriptor
This diagnostic procedure supports the following DTC:

DTC P0101 Mass Air Flow (MAF) Sensor Performance

Conditions for Running the DTC
DTC P0016, P0102, P0103, P0112, P0113, P0116, P0117, P0118, P0234, P0237, P0238, P0299, P0335, P0336, P0340, P0341, P0370, P0374, P2227, P2228, P2229 are not set.
The ignition 1 signal is between 9-18 volts.
The intake air temperature (IAT) is more than -20°C (-4°F).
The engine speed is less than 3,500 RPM.
The engine speed is steady within a range of 50 RPM.
The engine coolant temperature (ECT) is more than -20°C (-4°F).
The above conditions are met for more than 2 seconds.
DTC P0101 runs continuously within the enabling conditions.
Conditions for Setting the DTC
The ECM detects that the MAF sensor voltage signal is not within a predetermined range of the calculated MAF value for more than 12 seconds.

Diagnostic Aids
Any unmetered air that enters the engine downstream of the MAF sensor may cause this DTC to set.
A short between the signal circuit of the MAF sensor and the signal circuit of the intake air temperature (IAT) sensor will skew the MAF sensor higher than normal at idle and less than normal at higher air flows.
A malfunctioning MAF sensor can cause excessive engine emissions.
The MAF display should increase from 24-50 g/s at idle to 320 g/s or more at the 2-3 shift during a wide-open throttle (WOT) acceleration. If not, inspect for a restriction in the induction system or the exhaust system.
If the vehicle condition is intermittent, refer to Inducing Intermittent Fault Conditions in Wiring Systems and Intermittent Conditions .

[jah81592]

With the attached tune in the 1st post, is there a scaler that isn't being shown or where do I start to adjust this problem? Is there a tuneable correction which can be made to prevent the issue?-j

[jah81592]

Done a little more research, there is obviously a MAF test scaler missing in the tune template. This is a common problem, and raising the value is normal. Can the maf transfer function be adjusted to accomodate the K&N intake? HPT, Diesel tuners please assist. -j

[jah81592]

Got the problem fixed, used another software to adust the scaler and the problem was solved.