P139C Code

[RangerBill]

I get the code off and on. While I was doing that previous test, the code light was off. I drove around for 15 minutes and the code came back on. I have to use my laptop with FORScan to monitor the data. I did notice while moving but without my foot on the gas, it was almost always around -0.80 psi.

DPFE_UR showed "no fault" even when the code light was on.

Also, it is running rough and "studdering".

Mark

Replace the DPFE sensor and see if that fixes it.

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[airline tech]

yes - replace the sensor and then follow up with Live Data again to ensure readings come back to normal range if they do not - then the issue is within the EGR Tube Assembly or electrically (wiring) we can isolate that if the sensor does not bring it back to normal readings but since at KOEO the voltage is very near (new) normal - electrically it appears fine and the issue is withing the (pressure reading) capabilities

 

[emesel]

I hope to receive and replace the sensor tomorrow. But, is there a way to check if the orifice is clear? What about blowing compressed air in high or low pressure port and checking other port for flow?

 

[airline tech]

I hope to receive and replace the sensor tomorrow. But, is there a way to check if the orifice is clear? What about blowing compressed air in high or low pressure port and checking other port for flow?

The high pressure side - only as to check the orifice the tube must be removed, the only thing that you can do is disconnect both hoses and then koeo and note did the readings change

 

[emesel]

The high pressure side - only as to check the orifice the tube must be removed, the only thing that you can do is disconnect both hoses and then koeo and note did the readings change

I imagine it would have to be totally blocked for the readings to change when houses removed.

 

[airline tech]

My hunch is - it’s the sensor itself - the problem is that 99% of the members that have changed the sensor for Buck Surge did not have any PID data before they changed it - all of my data for T-Shoot is derived from expected readings from the very few (real failure) readings and my own Live Data (normal) drives , once you understand what is actually happening, you gain the understanding on how to monitor for the no code failures, and it’s all in the (Learned Zero) band and how much positive flow (accuracy) is left.
I will need to run Forscan and see if I can find the same PIDs as in the past it was not available, so this is actually some good news for others to post their PIDs as well - I imagine they are near the same readings as you have - the problem is the Buck / Surge appears before it codes P139C and the reason for that is it’s still in the Learned Zero Band , but when driving the positive flow is now not hitting it’s normal range voltage/ pressure- the PCM reacts by adding more EGR then the Buck Surge is felt although the sensor is still in a (PCM) believes the reading is normal until it pushes outside the band and becomes (untrustworthy) and sets the code - like you have

 

[emesel]

Finally had time to replace the sensor, and all seems good; no bucking and I believe values read normal (see below).

There was definitely some moisture in the high pressure tube and a bit in the low pressure tube. Prior to blowing the tubes out with air, I inserted a cotton swab and it came out damp, not dripping. I blew out the tubes onto a paper towel and, again, it was damp, not dripping. I then blew 30 pis air into the high pressure port. I also ran a short length of nylon trimmer string into both ports, and it came out with just a bit of black soot at the tip. Pics attached (sorry, pics are kind of lousy).

Data is below:

OLD SENSOR KOEO:

Tubes ON: 0.17 psi, 1.53 V

Tubes OFF: 0.12 psi, 1.53 V

NEW SENSOR:

KOEO:

Tubes OFF and ON the same values: -0.02 psi, 1.49 V

KOER:

At Idle Immediately after installation: 0.03 psi, 1.50 V

At Idle After 25 min. Drive: 0.01 psi, 1.50 V

While driving ~65-70 mph:

Delta P was -0.1 to 0.5 psi sometimes as low as -0.2 and up to 1.5 or 2.0

Voltage was 1 – 1.5 V sometimes up to 2 or even 3 briefly

Many thanks to Ranger Bill and Airline Tech for all the help and support. I’m interested in your thoughts on the data above.

BTW, I have the OBDLinkEX scanner and their OBDLink app, which is easier for me to use than FORScan. I purchased their Enhanced Network features which allowed me to monitor the EGR Sensor delta P and voltage while driving (easier than having to look at my laptop on the passenger seat).

Again, many thanks, Mark

 

[RangerBill]

Finally had time to replace the sensor, and all seems good; no bucking and I believe values read normal (see below).

There was definitely some moisture in the high pressure tube and a bit in the low pressure tube. Prior to blowing the tubes out with air, I inserted a cotton swab and it came out damp, not dripping. I blew out the tubes onto a paper towel and, again, it was damp, not dripping. I then blew 30 pis air into the high pressure port. I also ran a short length of nylon trimmer string into both ports, and it came out with just a bit of black soot at the tip. Pics attached (sorry, pics are kind of lousy).

Data is below:

OLD SENSOR KOEO:

Tubes ON: 0.17 psi, 1.53 V

Tubes OFF: 0.12 psi, 1.53 V

NEW SENSOR:

KOEO:

Tubes OFF and ON the same values: -0.02 psi, 1.49 V

KOER:

At Idle Immediately after installation: 0.03 psi, 1.50 V

At Idle After 25 min. Drive: 0.01 psi, 1.50 V

While driving ~65-70 mph:

Delta P was -0.1 to 0.5 psi sometimes as low as -0.2 and up to 1.5 or 2.0

Voltage was 1 – 1.5 V sometimes up to 2 or even 3 briefly

Many thanks to Ranger Bill and Airline Tech for all the help and support. I’m interested in your thoughts on the data above.

BTW, I have the OBDLinkEX scanner and their OBDLink app, which is easier for me to use than FORScan. I purchased their Enhanced Network features which allowed me to monitor the EGR Sensor delta P and voltage while driving (easier than having to look at my laptop on the passenger seat).

Again, many thanks, Mark

Looks good, there should be no EGR gasses flowing at idle and your old sensor was telling the PCM that you had flow when there shouldn't be any, thus causing the DTC code.

 

[emesel]

Looks good, there should be no EGR gasses flowing at idle and your old sensor was telling the PCM that you had flow when there shouldn't be any, thus causing the DTC code.

Got it. Thanks again, Mark

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