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Discussion Starter #1
I have a 2012 3.5 after Ford did the reflash of the transmission I started getting the MAF sensor code. Changed the sensor in the air cleaner and cleaned the other two. seamed to run good no codes. Stopped and fueled up and the codes are back. Any ideas what to check. Do I need to change the other two sensors?
 

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I have a 2012 3.5 after Ford did the reflash of the transmission I started getting the MAF sensor code. Changed the sensor in the air cleaner and cleaned the other two. seamed to run good no codes. Stopped and fueled up and the codes are back. Any ideas what to check. Do I need to change the other two sensors?
You have no MAF on your truck... what codes are you getting?
 

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Discussion Starter #3
I am getting P0104 and P0446. According to the code reader P0104 is a MAF sensor and P0046 EVAP control system. I changed the sensor in the air cleaner.
 

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I am getting P0104 and P0446. According to the code reader P0104 is a MAF sensor and P0046 EVAP control system. I changed the sensor in the air cleaner.
P0104 definitely is a MAF code, but your sensor at the filter is only used for air temp monitoring. Check the condition of wiring and connector. (there is a code that pops up in regards to this, but I don't believe it's P0104).
2011 was the only year that used a MAF, and even that one is debatable if the sensor is even used as a MAF.

P0446 is EVAP related... could be caused by vacuum leak, dirty fuel filler neck (flap), purge solenoid, etc.

If everything was fine before the reflash, I wonder if the new calibration is corrupt.

Good luck, and report back with update.
 

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Discussion Starter #5 (Edited)
Just to let you know there are three MAF sensors on the 2012 3.5. The one in the air filter may be a air temp but there is one on the intake pipe on the front of the engine and one on top of the engine. I have cleaned the filler cap door and checked for vacum leaks. Can't find the Purge valve but will continue to look. Thanks for the input,correct
 

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Just to let you know there are three MAF sensors on the 2012 3.5. The one in the air filter may be a air temp but there is one on the intake pipe on the front on the front of the engine and one on top of the engine. I have cleaned the filler cap door and checked for vacum leaks. Can't find the Purge valve but will continue to look. Thanks for the input,
Which one of these does your sensor at the airbox look like? MAP sensor.jpg MAF sensor.jpg
 

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MAF sensor (2011) is not used to read air flow, but rather Air Temp. I've even "heard" of a few 2012's with the MAF as well.

Eventually Ford completely switched to only MAP and IAT sensors.

These are speed density vehicles, so the MAF (even if it exist), is only used for reading air temp, not flow. Just fyi.
 

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MAF sensor (2011) is not used to read air flow, but rather Air Temp. I've even "heard" of a few 2012's with the MAF as well.

Eventually Ford completely switched to only MAP and IAT sensors.

These are speed density vehicles, so the MAF (even if it exist), is only used for reading air temp, not flow. Just fyi.
I concur. Thanks for elaborating.

The one in the air box looks like the top one as well the other two look the same.
The top picture is a MAP sensor. FYI, Boostking is a professional tuner for SCT, so he knows the parameters of these engines pretty well.

Good luck, and please Keep us updated on progress.
 

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Discussion Starter #11
Thank you for clarifying that. It's funny the parts guy a Ford said it was a MAF sensor when they ordered a new one for me.
 

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I'm sorry if I wasnt clear. You may very well have a MAF sensor. However, a MAF sensor also traditionally houses an IAT sensor. In the early production of the F150 Ecoboost, Ford used a MAF sensor, but really only utilized the IAT sensor built in. Kinda a waste. MAF is usually used to measure airflow, but this PCM doesnt utilize that.

From a tuning perspective, your PCM should have zero MAF signal, but always have an IAT sensor signal. Perhaps I'm a bit out of my realm here because mine is a 2013 with only MAP/TIP sensors with integrated IAT sensors. I am a bit confused on how it would trip a MAF related code if the PCM is only pinned for the IAT sensor to be of any use. I know there is no MAF transfer function on any EcoBoost calibration I've ever seen.

Point is I was merely making sure it was understood that the MAF does not actually read airflow on these trucks, seems like Ford was borrowing from the parts bin in the early F150 Eco's. Who knows really. Hope you do find a solution and post it back here.
 

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I'm sorry if I wasnt clear. You may very well have a MAF sensor. However, a MAF sensor also traditionally houses an IAT sensor. In the early production of the F150 Ecoboost, Ford used a MAF sensor, but really only utilized the IAT sensor built in. Kinda a waste. MAF is usually used to measure airflow, but this PCM doesnt utilize that.

From a tuning perspective, your PCM should have zero MAF signal, but always have an IAT sensor signal. Perhaps I'm a bit out of my realm here because mine is a 2013 with only MAP/TIP sensors with integrated IAT sensors. I am a bit confused on how it would trip a MAF related code if the PCM is only pinned for the IAT sensor to be of any use. I know there is no MAF transfer function on any EcoBoost calibration I've ever seen.

Point is I was merely making sure it was understood that the MAF does not actually read airflow on these trucks, seems like Ford was borrowing from the parts bin in the early F150 Eco's. Who knows really. Hope you do find a solution and post it back here.
The OP just had his trans recall flash performed. From what I gather, he's getting the codes after the re-flash... I wonder if it's possible the new calibration is corrupt.
 

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I know it sucks, but since it happened following the recall reflash, I would take it back and ask that they help figure it out. This is quite the odd one to have.

Generally speaking, there really cant be a "corrupt flash" and you still drive your vehicle. The data is checksummed in several areas and the PCM has to see that all check sums are correct or it will not even let the engine run. For example, if I write you a custom tune, the checksums are corrected by the device and entered in. If we didnt do that, the custom tune would load, but the PCM would say NOPE and not allow you to start.
 

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Discussion Starter #15
ok I give up replaced the MAP sensor in the air cleaner, cleaned the two remaining MAP sensors and replaced the Purge valve. Cleaned the gas filler door, drove it for about 60 miles codes went away got to a 1/4 tank of gas came back on. Filled up came on for about 20 miles reset the codes and now it off. Going to make an appointment with Ford and find out what is going on. Thanks for the info.
 

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Discussion Starter #16 (Edited)
Update we'll after several hours of chasing wires to no avail I purchased the Purge valve that is in the box under the truck at $78. Pulled the old one and put in the new one reset the codes and after 700 miles the codes have a not come back keeping my fingers crossed.
 

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Discussion Starter #18 (Edited)
Yes the Purge selonid as Ford calls it is located on the driver's side under the door on the frame in a black box. The part number is 9U5Z 9F945F. Simple to remove it twists to unlock, pull it out it does take some effort to get it out. Unplug the connector install in reverse order.
 
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