My car is running fine. But several weeks ago I started getting random P0101 codes with the CEL coming on. It stopped happening and then started again today. Seems to come on shortly after cold starts.

Could someone list the causes of this code please....

DH

 

Often on a decent cammed car it is set off by the knock sensors picking up the lope of the cam, itll often come and go randomly. Solution is desensitizing the knock sensors

 

My cam is only a 224/228 @114 XER COMP

But my tuner did recently (I think) increased the sensitivity to help get rid of some pinging issues...along with adding fuel. Ping is gone!!!!

DH

 

motorbuilt,

Why would knock sensors set off a maf sensor code?

 

P0101 is MAF Sensor Performance in my PCM. What would that have to do with the knock sensors?

There is a MAF rationality test that the PCM performs. If it isn't within the ranges defined in the PCM when compared to MAP/VE, it might throw that code. I bet that's where the problem lies.

 

Are you saying my PCM is crazy ????

Seriously.....my PCM has been tuned MANY times over the last 3 years ..... could it be dying !!!!!

DH

 

Are we talking about a stock MAF?

 

A picture may be a little more helpful. You see those numbers in the cells under the "Value" column? They represent the allowable difference between the airflow calculated by the MAF vs the airflow calculated using the MAP (speed density). If the difference between the two calculations is greater than this value, I believe it will set a P0101.

 

Yes stock/screened MAF with IAT sensor !!!!!

DH

 

Thank you for the help. This will make a lot more sense to my TUNER than to me. I am just getting started in learning tuning and will be getting HPT shortly.

So I was looking for a list of possibilities for P0101. I read all the related posts in this forum. What I have found so far is:

1. broken/shorted wires to MAF
2. dirty MAF
3. failed MAF
4. Bad MAP sensor
5. Failed rationality test

Is there more.......

DH

 

Here's some info that might be useful. I have also seen a few cars set this code due to a vaccum leak from bad intake gaskets. When cold, mostly in the winter time, on start-up the engine will draw unmetered air past the gasket creating a lean condition. Sometimes, it will go away when the vehicle warms up and the gasket heats and expands. Though the p0101 is usually accompanied with p0171, p0174, and sometimes p0300 dtc's, and mostly on trucks and suv's. It's possible your issue is what the PI is talking about below. Hope this helps.

Subject: Service VME - 4.8 5.3 6.0 LM4 LM7 LR4 LQ4 LQ9 GEN III Engines with MAF Sensor Code P0101 - kw driveability fluctuation idle intermittent MAP rough stall surge hesitation #PI01624A - (04/05/2004)


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When servicing the vehicle with the VIN you entered, the following diagnosis might be helpful if the vehicle exhibits the described symptoms.

SERVICE VME
This message applies to all 1999 through 2004 Chevrolet, GMC, Olds, Buick and Cadillac pick-ups and utilities that are equipped with either the 4.8 liter, 5.3 liter or 6.0 liter Gen 3 V-8 engines. Recent warranty analysis indicates that both the MAF, or mass airflow sensor, and the MAP, or manifold absolute pressure sensor, are being replaced for a MAF sensor code P0101. The cause may actually be a MAP sensor failure causing the MAF sensor code. One of the MAP sensor’s primary functions is the calculation of the speed density formula, which is compared to the MAF sensor reading. Should the MAP sensor fail, the PCM may interpret this as a MAF sensor concern and set a P0101 code. If diagnostics are followed thoroughly the technician may find a MAP sensor failure causing this condition. In conclusion, when a MAF sensor code of P0101 is found the technician needs to verify the proper operation of the MAP sensor before concluding that the MAF sensor requires replacement.

MODELS:

(00-04 Chevrolet Silverado Truck C1,C2,C3) and (00-04 Chevrolet Tahoe C1,C2,C3) and (00-04 Chevrolet Suburban C1,C2,C3) and (00-04 GMC Sierra Truck C1,C2,C3) and (00-04 GMC Yukon C1, C2, C3) and (00-04 GMC Yukon XL C1, C2 C3) and (02-04 Cadillac, Escalade, C6) and (03-04 Cadillac, EXT, C1) and (02-043 Chevrolet, Avalanche, K1, K2) and (02-04 Chevrolet Silverado Truck K1, K2, K3) and (02-04 GMC Sierra Truck K1, K2, K3) and (02-04 Chevrolet Tahoe, K1, K2, K3) and (02- 04 Chevrolet Suburban, K1, K2, K3) and (03 Chevrolet Camaro) and (02-04 Chevrolet Corvette) and (03 Pontiac Firebird) and (02-04 GMC, Yukon, K1, K2, K3) and (02-04 GMC, Yukon XL, C1,C2, C3) and (00-04 GMC, Yukon XL, K1, K2, K3) and (03-04 GMC S1 T1) and (03-04 Chevrolet S1 T1) and (03-04 Chevrolet Express G1, G2) and (03-04 GMC Savana G1, G2)

.

 

Also see www.gearchatter.com/viewtopic10728.php

 

This is very good info !!

As a matter of fact I have a Fast Intake and I have heard they have two issues:

1. warpage---------therefore leaking
2. rubbing the MAP sensor against the firewall


DH

 

I got the code again today. About 10 minutes after startup and it was cold out.

CEL came on. Checked the DIC and it listed the P0101 as H only no C ...... does that make any sense??


DH

 

No code for 9 days then out of the blue I get it again.

DH

 

Did you have your tuner change that table I posted???

 

No I did not !!!!!

But I will print that info out this weekend and go over it with him.

Thanks again

DH

 

its under engine diagnostics-airflow if i remember correctly fwiw.

 

Thanks

I can't wait to get my HPTuner so I can check this stuff myself !!!!!

DH