UPDATE replaced MAF sensor, MAP sensor, still SES light P0101 code?? 02 2500 av

[themoneypit]

hi everyone, new here, so not sure if i couldve found a solution to this or not....  but anyways, my av (02 2500 4x4 54k miles) when i got it and was driving it home from colorado the service engine soon light came on.  i went to auto zone, scanned it and it said mass air flow sensor.  so i changed it, light went out, and stayed out for a few days.  then came on, scanned again, same code.  the idiot at auto zone says, well it could be the MAP sensor too.. so i replaced that, same thing off for a few days, then back on.  it ALWAYS comes on when climbing a hill, and getting into the throttle.  when the light is on, i also notice it shifts funny into overdrive (thought it was my imagination at first but its not).  it stays on for a couple days, then will go off at start up and stay off for a few days.  IM STUMPED

it never gave me an actual code number when it was scanned, but im sure someone knows which code it is here.  any help as to what i can try now or what this could be would sure be AWESOME!!!  anyone ever have this same problem??

[ItsStopher]

We need the code #

Do you have an after market oiled air filter?

[themoneypit]

ill have to go have it scanned again to get the code number.  im sure its a common code. its for the mass air flow sensor. 

there is no aftermarket air filter.  it also received complete tune up after i got it home in addition to the mass air flow and map sensors.  still to no avail.?.

[ItsStopher]

P0101
The actual frequency signal from the MAF sensor is not within a predetermined range of the PCM calculated MAF value for more than 0.5 seconds.

P0102
The PCM detects that the MAF sensor frequency signal is less than 1,300 Hz for more than 1.2 seconds.

P0103
The PCM detects that the MAF sensor frequency signal is more than 13,500 Hertz for more than 1.2 seconds.

[themoneypit]

gotcha.. theres more than one.  ill go tomorrow morning and see which one i have and post up here

[themoneypit]

P0101
The actual frequency signal from the MAF sensor is not within a predetermined range of the PCM calculated MAF value for more than 0.5 seconds.

P0102
The PCM detects that the MAF sensor frequency signal is less than 1,300 Hz for more than 1.2 seconds.

P0103
The PCM detects that the MAF sensor frequency signal is more than 13,500 Hertz for more than 1.2 seconds.

the fact that im getting one of these when the truck is under load, or going up a steep hill, does that ring a bell to anyone as to what the problem can be?  not to mention, i replaced the MAF sensor already, so im hoping that isnt the problem, that it has to be something stupid?!?

[MS03 2500]

We would only be guessing, sorry.

[themoneypit]

We would only be guessing, sorry.

im hoping someone has had the same problem with theirs, and can steer me in the right direction... ill get the proper code reading 2morrow thou, and see if that helps..

[MS03 2500]

You know you can buy a scanner and do it yourself. The small ones are cheap under 50 buck and will pay for themselves.

[themoneypit]

You know you can buy a scanner and do it yourself. The small ones are cheap under 50 buck and will pay for themselves.

yeah but its FREE to  go to advance auto, or auto zone or any of those chain stores and use theirs    which i just did and im getting

CODE P-0101   

[themoneypit]

OK. so i go back to autozone, they re-read the code. it shows p0101.  i tell them to warranty their MAF sensor, they hem and haw saying it could be something else causing the code such as a vacuum leak.  i tell them, that its showing the code for the MAF,  f---ing warranty it.  so finally, they agree to.  i R&R it with another one from them, reset the code, and all seems good.  today, i drive about 200 miles towing a trailer with a subaru on it, no problems so i think all is well.  i get home, unload the car, unhook the trailer, and head to the store.  the damn light came on AGAIN!!! i have it read (at advance auto this time cuz it was rite there) and sure enough P0101.... is it possible that i keep getting crap sensors from them?? or can my truck sort of eat them up for some reason??  i reset the code again, and as of now the light is off.  anyone have any kind of input or advice for me to try here?? PLEASE      this is a reman part that i put on there.. maybe i shouldve splurged for the "new" one

[ItsStopher]

Diagnostic Aids for P0101
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.

[ItsStopher]

More things to check......

Inspect for the following conditions:

A restricted air intake duct
A collapsed air intake duct
A misaligned air intake duct
A dirty air filter element
A deteriorating air filter element
Any objects blocking the air inlet screen of the MAF sensor
Any debris on the sensing elements of the MAF sensor
Any vacuum leak downstream of the MAF sensor
A poor vacuum connection at the MAP sensor
A restricted exhaust system

[MS03 2500]

Did a little searching here at at another site I trust.

It seems this is a problem with the 2500 series trucks many times after towing it comes on.

What I can suggest it to check for air leaks between the throttle body and the MAF.
Check the condition of the plug on the MAF for corrosion.
Try disconnecting the battery for 15 minute so it will reset the PCM, if you do this turn off all the electrical system first. A/C and radio

[themoneypit]

More things to check......

Inspect for the following conditions:

A restricted air intake duct
A collapsed air intake duct
A misaligned air intake duct
A dirty air filter element
A deteriorating air filter element
Any objects blocking the air inlet screen of the MAF sensor
Any debris on the sensing elements of the MAF sensor
Any vacuum leak downstream of the MAF sensor
A poor vacuum connection at the MAP sensor
A restricted exhaust system

air intake duct is aligned properly, and no restrictions, also shows no signs of a leak. 
air filter is new
MAF sensor is a new rebuilt from auto zone (second one had em warranty the first)
MAP sensor was replaced, no signs of vacuum leak there
exhaust is fine, just recently passed emissions

when i had autozone warranty the other sensor, the truck ran freakin great!!  i pulled my empty trailer from CT to NY to pick up a subaru with no problems, i was doing 75-80+ the whole trip there.  picked up the car, towed it home, again 75 avg speed, no problems.  im tellin ya, the truck ran better than ever.  then afterwards, the light came on again for no apparent reason. 

i think at this point, im going to take the MAF sensor out of our RV and try it on the av.  the RV has the same 8.1l big block as the av, albeit a few years newer, but i believe their the same.  im going to try this tomorrow, and will post results when i get them.  if i get no light with the GM sensor out of my RV, i will go back to autozone and demand my money back for the part, and tell em to stick it where the sun doesnt shine LOL..

[MS03 2500]

Just curious did you try the battery disconnect and make the PCM recalibrate

[themoneypit]

Just curious did you try the battery disconnect and make the PCM recalibrate

yes, ive done that more than once...

[Intimidatoruag]

check the wires in the harness to the MAF ... maybe you have a wire shorting out ....