EGR DPFE Sensor Assembly Replacement Write-Up (LB5Z-9J433-B)

[lariat]

One has absolutely nothing to do with the other. The water destroying the sensor is coming from condensation from the exhaust gases. Best to consider the part as a wear item. Dryer climates should have less of an issue.

This is my understanding...

"The water destroying the sensor is coming from condensation from the exhaust gases." Hence my curiosity and question. In theory, nothing is being resolved - replacement isn't technically solving anything - only a temporary solution. I live in a dryer climate....and have the issue.

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[micl9]

more annoying is the cost keeps creeping up now that this is a "wear" item. I replaced mine in Sep '22. It lasted maybe a year - now I just feather the throttle when starting to roll.

 

[airline tech]

As I have stated - I did a deep dive into the compete EGR System, this is an example of the EGR Tube section - there are quite a few variables - I have not had the time to fully complete the document but this section (as it is currently written) provides a basic overview of the moisture accumulation in the tube assembly.

No - we cannot fully eliminate the moisture issue and yes it can reoccur (Repeat)
again I need to do some more (refining / editing) my rough draft - I currently have 83 Pages of system operation that I need to final draft - I have a basic understanding of what is causing the issues and it mainly lies in the - EGR Cooler (Lower Temps + EGR Tube) Temp + EGR Event Cycles (Duration) how long heat (EGR Flow) is being supplied to the tube.

I wanted a better system operation explanation than the manuals give , so I combined the manuals + Live Data (Drives) + Google Searches and put together a ref guide that makes logical sense.
Once you view a Live Data - Drive and record the (System Operation) you have a better view on why and how (moisture or DPFE Sensor Bias) causes the PCM to command more EGR than needed - this is the Buck-Surge and it all happens before it hits code limits (P139C)
it boils down to what is the (PCM's Learned - (0-Flow) voltage and pressure reading of the DPFE Sensor and its reaction time to EGR Flow.

He is my basic - EGR Tube (Section) - I think I still need to do some editing but for the most part is accurate.

 

[airline tech]

Here is an example of a - Live Data (Event) - EGR Valve opened to EGR Valve Closed - Total Estimated duration time - Zero to Zero about 30 seconds

In this example (IF) we have a DPFE sensor that is not reporting correct (Voltage & Pressure) then the PCM would react by commanding the (EGR Command) to open farther to satisfy what the PCM is expecting form the DPFE sensor thus flooding the engine with excessive EGR Flow, this leads to the - Buck-Surge (issues)

So if you look at (Zero - Flow) this is the (Learned Zero) flow (-0.07 PSI & 1.46 volts)
any moisture in the sensor or tube or sensor bias (electrically) can throw off the readings or reaction (sensitivity) to the EGR Flow itself.
Note the longer (duration) of the EGR Event - the higher the EGRT (Temp)
This short duration (cycle) is the temperature fluctuations inside the tube.
Note also this drive cycle was in -Winter Months, so I planned on a (Summer - Drive) and note any changes on the EGR Temps - not yet completed

 

[lariat]

It seems condensation needs an escape route or new design to address the moisture.

 

[airline tech]

For a compare - 92 degrees the EGRT in the tube fluctuates between 140 and 176 EGR closed and open - via a quick test drive - so slightly hotter than a winter drive - the tube holds the heat

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