P0101 (Intake Air Volume: Low) Warning after replacing dirty air filters

[josiahgarber]

I'm getting a P0101 error (Intake Air Volume: Low) after replacing my air filters on my Kubota L4701. I'm curious if I should send it in for service or if there are some lower cost things I should try first.

Out of curiosity I put back in the dirty air filters and cleared the code. The code did not come back with the dirty air filters. Once I put the new filters back in, the code came back fairly quickly.

I tightened up hose clamps to try to prevent any air leaks. I also removed the MAF sensor and cleaned it. P0101 code still returns.

I did have some fairly frequent regens prior to replacing the air filters as I was discing in dusty conditions. Perhaps it's possible the DPF is restricting airflow?

I am considering having the tractor picked up for service or replacing the MAF sensor, but would appreciate anyone's opinions about what the problem might be or additional troubleshooting steps I could take. Thank you.

 

[Russell King]

One question for you to be 1000% sure of:

Are there any plastic wrappers on the new filters that are restricting the air flow?

 

[josiahgarber]

One question for you to be 1000% sure of:

Are there any plastic wrappers on the new filters that are restricting the air flow?

Just checked and I'm sure there are no plastic wrappers on the filters. I was hoping I would see that.

 

[Hugo Habicht]

The error is intake air flow, hence the new filters have higher air flow resistance than the old dirty ones. Are they genuine and the correct Kubota filters?

 

[josiahgarber]

The error is intake air flow, hence the new filters have higher air flow resistance than the old dirty ones. Are they genuine and the correct Kubota filters?

Yes, as far as I can tell they are genuine and the correct ones. I purchased them from the dealer. Perhaps I should purchase again and test as I can use the filters in the future.

 

[mikester]

Check the intake and ducts for critters building nests

 

[josiahgarber]

Check the intake and ducts for critters building nests

Remove the intake and tubing all the way to the air flow sensor and everything looks good.


Is it unlikely that the maf sensor is bad?

 

[Hugo Habicht]

Remove the intake and tubing all the way to the air flow sensor and everything looks good.

Is it unlikely that the maf sensor is bad?

If the sensor is bad (i.e. sensing differential pressure too high) it would do that with both filters. That the electronics thinks the new fliter is more blocked than the dirty old filters does not make any sense. Weird...

 

[lynnmor]

Shine a light thru the new and old filters to see if the new ones were made of a more restrictive paper.

 

[TheOldHokie]

If the sensor is bad (i.e. sensing differential pressure too high) it would do that with both filters. That the electronics thinks the new fliter is more blocked than the dirty old filters does not make any sense. Weird...

I suspect the filter is a red herring and the problem lies elsewhere.

Dan

 

[McMXi]

If the sensor is bad (i.e. sensing differential pressure too high) it would do that with both filters. That the electronics thinks the new fliter is more blocked than the dirty old filters does not make any sense. Weird...

Those two air filters (inner and outer) are used on a lot of Kubota models including some excavators. My MX6000 uses the same filters. I would switch the old filters and new filters in and out a few times and see if the error code tracks 100% of the time. If it does, it would imply an issue with the new filters. Stranger things have occurred in this world.

If you look at the Messick's website you can see that many parts replace earlier parts and the filters are no exception. Who knows what the differences are but could be dimensional changes, different vendor, different materials etc. If nothing else, the OP should verify that the part numbers match the latest versions as listed by Messick's.

 

[JasonW]

If it happened right after you installed new filters what are the chances you damaged a sensor or wiring?

 

[McMXi]

If it happened right after you installed new filters what are the chances you damaged a sensor or wiring?

I would say extremely low given the OP's following statement:

"Out of curiosity I put back in the dirty air filters and cleared the code. The code did not come back with the dirty air filters. Once I put the new filters back in, the code came back fairly quickly."

We're often relying upon the accuracy of the information being supplied and the the integrity of the person posting, but I see no reason at this point to have any doubts. It'll be interesting to learn the actual cause of this issue.

 

[JasonW]

I would say extremely low given the OP's following statement:

"Out of curiosity I put back in the dirty air filters and cleared the code. The code did not come back with the dirty air filters. Once I put the new filters back in, the code came back fairly quickly."

We're often relying upon the accuracy of the information being supplied and the the integrity of the person posting, but I see no reason at this point to have any doubts. It'll be interesting to learn the actual cause of this issue.

True I completely missed that part.

 

[josiahgarber]

Unfortunately, I don't have the old filters anymore. The new ones match the correct part numbers.

Yes, I was able to use the tractor by putting the old filters back in. I was trying to finish planting before the rain came so I cleared the code, put the old filters back in and was able to use the tractor without it throwing a code.

Now that the new filters are back in, code comes back. Seems like it happens after engine warms up or rpms are increased.

I agree that it doesn't seem to make much sense. The old dirty filters should restrict airflow, so why would I only get the code p0101 (low airflow) when I have the new filters in. I have no idea.

I may have Messicks bring the tractor in for service, and see what they find.

I was hoping for a low cost solution, but everything I've tried so far hasn't worked. I'm tempted to get some painters tape and wrap it around half the outer air filter to restrict airflow (simulating the dirty filters), clear the code and see if it comes back or not.

I thought about buying the mass airflow sensor and replacing it (already cleaned it once), but I've been in situations in the past where I've spent too much money guessing at repairs.

FWIW Messicks said they thought it was the air slow sensor. I would expect the code to appear right away if it was a bad air flow sensor, but I'm not really a mechanic.

 

[josiahgarber]

I suspect the filter is a red herring and the problem lies elsewhere.

Dan

That is my suspicion as well.

 

[josiahgarber]

If it happened right after you installed new filters what are the chances you damaged a sensor or wiring?

Seems possible. The air flow sensor is fairly far downstream from the airbox, but it could have been a dust or dirt contamination issue.

My best guess is a bad sensor or a DPF issue since I was having frequent regens prior to this code.