What's inside a DPFE Sensor (Pics Inside)

[ctechbob]

Your not supposed to open those !!!

What else am I supposed to do at 3 a.m. when the family is asleep and I've got to be awake to get ready for my next shift?

It's probably a good thing I don't have a separate shop that I could go to, I would get into a lot more trouble.

Sponsored

 

[Msfitoy]

What else am I supposed to do at 3 a.m. when the family is asleep and I've got to be awake to get ready for my next shift?

It's probably a good thing I don't have a separate shop that I could go to, I would get into a lot more trouble.

At 3am while waiting for next shift, I'd be playing loud music...

 

[ctechbob]

At 3am while waiting for next shift, I'd be playing loud music...

Lol, that would cost me half, the wife would file for divorce.....

 

[RedDakooter05]

Wonder if relocating this thing would make any difference....

 

[ctechbob]

Wonder if relocating this thing would make any difference....

Wouldn't think so. Might delay the problem, or even cause a different problem with signal timing (longer path, more flexible pipe, etc). Even my desiccant idea might just delay the problem.

 

[ChiefQM]

Even though there is no flow during operation there is air “migration” so it could be contaminated over time. My thought is that, is FORD aware that their supplier has delivered a known failure part, or has the vendor, or vendors supplier, omitted a process that would mitigate this failure.
A whole new can of worms!!!

We all know that the ancient Ford Explorer Firestone tire incident was caused by Ford eliminating the department that tracked this kind of trend, and ended up paying 100 time more in lawsuits than that dept ever cost.
Is this an EPA issue? Do they fail before 100000 miles?

From the Motorcraft site.

Durability test specification- 10-years/150,000 miles

My first one quit before 12,400 miles, which was the mileage when I bought it, and I suspect that is the reason it was traded in.

 

[2021Ranger]

Maybe just install a water separator as that seems like the issue with them.

 

[Beez]

I think MacGyvering a desiccant or a water separator would likely help, but the concern might be a negative impact, or effect on the pressure differential that the sensor is monitoring?

 

[docthndr]

Its job is to report the pressure drop across the EGR passages so the PCM knows exactly how much exhaust gas is being recirculated. These sensors don’t fail because of temperature readings; they fail because the internal silicone/gel diaphragm breaks down over time from heat and exhaust exposure, which causes the voltage signal to drift.


Where people get confused is why this creates transmission problems. The transmission isn’t actually failing—Ford’s shift logic is torque-based, not RPM-based. The PCM calculates real engine torque using multiple sensors, including EGR flow data. When the sensor starts sending a bad signal, the PCM gets the wrong EGR reading, which throws off combustion, air/fuel balance, and ultimately the engine’s torque model. Since the TCM relies on that torque estimate to time shifts, a bad sensor leads to harsh shifts, late or early shifts, weird downshifts, and general shift confusion. The transmission is reacting to bad information, not mechanical failure. Replace the sensor and the shifting issues typically disappear because the torque model corrects itself.

 

[RangerBill]

Its job is to report the pressure drop across the EGR passages so the PCM knows exactly how much exhaust gas is being recirculated. These sensors don’t fail because of temperature readings; they fail because the internal silicone/gel diaphragm breaks down over time from heat and exhaust exposure, which causes the voltage signal to drift.


Where people get confused is why this creates transmission problems. The transmission isn’t actually failing—Ford’s shift logic is torque-based, not RPM-based. The PCM calculates real engine torque using multiple sensors, including EGR flow data. When the sensor starts sending a bad signal, the PCM gets the wrong EGR reading, which throws off combustion, air/fuel balance, and ultimately the engine’s torque model. Since the TCM relies on that torque estimate to time shifts, a bad sensor leads to harsh shifts, late or early shifts, weird downshifts, and general shift confusion. The transmission is reacting to bad information, not mechanical failure. Replace the sensor and the shifting issues typically disappear because the torque model corrects itself.

They fail because they get water/moisture from the exhaust gasses into the sensor causing the engine to miss badly due to too much recirculated exhaust gases. The failed sensor mis-reads the EGR gas flow and the PCM in turn increases the EGR valve opening causing engine miss, especially at lower road speeds, part throttle.

 

[PltFX4]

Question: Anyone know what level of pressure we are talking about in the DPFE?? micro PSI?? regular PSI??

Also, I like @Racket suggestion above of experimenting with those inline moisture absorber (IMA).

So, to tie these two items together and give @ctechbob something to do at 3am... i.e.: bench testing the DPFE with the IMA attached and using a "compressor" of the appropriate level of PSI needed and a volt meter (this sound more like it's up @airline tech alley) and see how it goes.

 

[ctechbob]

Question: Anyone know what level of pressure we are talking about in the DPFE?? micro PSI?? regular PSI??

Also, I like @Racket suggestion above of experimenting with those inline moisture absorber (IMA).

So, to tie these two items together and give @ctechbob something to do at 3am... i.e.: bench testing the DPFE with the IMA attached and using a "compressor" of the appropriate level of PSI needed and a volt meter (this sound more like it's up @airline tech alley) and see how it goes.

Sadly, I'll have to leave it up to the rest of you to investigate that. The Ranger is long gone and I sold off my stock of DPFE's to a member here.

As far as I can tell, my Powerboost doesn't use a DPFE sensor....but I've got plenty of new parts that will fail.

 

[PltFX4]

Sadly, I'll have to leave it up to the rest of you to investigate that. The Ranger is long gone and I sold off my stock of DPFE's to a member here.

As far as I can tell, my Powerboost doesn't use a DPFE sensor....but I've got plenty of new parts that will fail.

Sorry, I missed that this was a post that started in 2023...

Sponsored