Check Engine Light and P04DB code - 3rd occurrence

[capetomb]

Hi everyone. I bought my 2025 2.7 Lariat in late November. Since then, the CEL has come on twice showing P04DB and been back to the dealership both times. The first time they tightened the dipstick tube and cleared codes. The CEL came on again about a week after that. They replaced the crankcase pressure sensor and cleared codes codes. All was well for a couple months. I got my first oil change and a week later the CEL is back on for the third time. It’s going back to the dealership on Thursday. In the meantime, I had AutoZone pull the code and it is P04DB again. It seems to drive okay, as best I can tell. MPGs might be dropping slightly if anything.

Anyone had experience with this? Is it safe to drive on (I get mixed feedback from Google searches)? I’ve checked the obvious loose hoses and such, with no luck. This will be the third occurrence of the issue so I’m getting close to Lemon Law status. I really don’t want to go that route, but also don’t want to be worrying about my truck failing every time I get in it.

Thanks in advance.

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[Arsenall11]

Sounds like they are moving down the items that can cause the issue. Not advisable to drive with the issue, next they may replace the filter. It’s a pain but hope they give you a loaner, take it back again.

 

[AugPal]

If they can't get it fixed the next time you bring it in, check and see what Massachusetts Lemon Law says

 

[MasterCylinder]

Hi everyone. I bought my 2025 2.7 Lariat in late November. Since then, the CEL has come on twice showing P04DB and been back to the dealership both times. The first time they tightened the dipstick tube and cleared codes. The CEL came on again about a week after that. They replaced the crankcase pressure sensor and cleared codes codes. All was well for a couple months. I got my first oil change and a week later the CEL is back on for the third time. It’s going back to the dealership on Thursday. In the meantime, I had AutoZone pull the code and it is P04DB again. It seems to drive okay, as best I can tell. MPGs might be dropping slightly if anything.

Anyone had experience with this? Is it safe to drive on (I get mixed feedback from Google searches)? I’ve checked the obvious loose hoses and such, with no luck. This will be the third occurrence of the issue so I’m getting close to Lemon Law status. I really don’t want to go that route, but also don’t want to be worrying about my truck failing every time I get in it.

Thanks in advance.

Actually your getting their standard run down for the code. Replacing parts that are cheap for them to do instead of doing an hands on diagnostics with a real technician that knows his stuff because it's time consuming. This code relates to the crankcase ventilation system seeing pressure (lack of vacuum) instead of when the pcm wants to see vacuum. Tell them in a nice voice. I've been reasonable in my attempts to get this fixed. This is the third time I've been in and X amount of days and time away from my job. If I can't get it fixed on this attempt I will be investigating our lemon laws for my other options. It'll get fixed!

 

[capetomb]

Thanks all. I spent a fair amount of time researching the lemon law option this weekend, along with buyback and BBB Auto Line. I’m not there yet—MA requires a formal notice then a fourth chance before lemon law kicks in. But I’ll definitely take @MasterCylinder advice and nicely let them know I’m prepared for the next step. It’s tough cuz I recognize it could me multiple causes and it just takes time to go through those with process of elimination. But this is my only vehicle, so it’s a pretty big disturbance each time it goes down.

 

[MasterCylinder]

Thanks all. I spent a fair amount of time researching the lemon law option this weekend, along with buyback and BBB Auto Line. I’m not there yet—MA requires a formal notice then a fourth chance before lemon law kicks in. But I’ll definitely take @MasterCylinder advice and nicely let them know I’m prepared for the next step. It’s tough cuz I recognize it could me multiple causes and it just takes time to go through those with process of elimination. But this is my only vehicle, so it’s a pretty big disturbance each time it goes down.

Good luck, hope it turns out for you, especially being your only ride!!

 

[Grand Nat]

Did the technician check the PCV valve on the 2.7 it's possible it could be faulty. You might think it's not likely to be the problem however is easy to check.

 

[capetomb]

Did the technician check the PCV valve on the 2.7 it's possible it could be faulty. You might think it's not likely to be the problem however is easy to check.

Good question, I’m honestly not sure. I remember seeing some discussion of PCV when I googled the code. I checked some of the lines running to/from the PCV but didn’t see any obvious issues. Not sure about the valve itself. I’m hoping they’ll check that (and everything else) on this next visit.

 

[capetomb]

The dealership finally got my truck in today. They found that there is a TSB out for this issue:

https://static.oemdtc.com/NHTSA-PDFs/MC-11028839-0001.pdf

It looks like the TSB just came out February 2026, which is probably why they didn’t catch that on my prior two visits. Fingers crossed this will solve it. At least with a TSB out, I know I’m not the only one getting it. I suppose that makes me feel better?

 

[Grand Nat]

The dealership finally got my truck in today. They found that there is a TSB out for this issue:

https://static.oemdtc.com/NHTSA-PDFs/MC-11028839-0001.pdf

It looks like the TSB just came out February 2026, which is probably why they didn’t catch that on my prior two visits. Fingers crossed this will solve it. At least with a TSB out, I know I’m not the only one getting it. I suppose that makes me feel better?

Hope that solves the problem. The bulletin did say that a modified PCV system or air intake system could cause inaccurate results. I would guess that you did not modify anything.

 

[capetomb]

I would guess that you did not modify anything.

Correct—mine is all stock.

 

[Jason B]

Should be a quick fix, then, and be back on the road soon.

I see that they always add this statement when PCM has to be reprogrammed:

Notice it says, 'learn transmission unique parameters', not 'learn drivers' habits'.

 

[capetomb]

Should be a quick fix, then, and be back on the road soon.

I see that they always add this statement when PCM has to be reprogrammed:

Notice it says, 'learn transmission unique parameters', not 'learn drivers' habits'.

Yep, it was a quick fix. I sure felt the difference in the transmission. The first few shifts were pretty clunky, but already getting smoother after a couple short drives.

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