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DPF Increased Regens

LMM: 
13K views 14 replies 9 participants last post by  sfcjones 
#1 ·
Hey Fellas,


I got a problem that I know I cant figure out on my own so lets get to it.
I got a new to me 2007.5 LMM last year and I love my little rig so I started Moding her a bit, put an AFE CAI(dry) to get that boost in MPGs but my DPF has been regening 3 times every 2 tanks instead of once every tank as she did before I put it on. Everything looks ok under the hood my oil only has about 4k miles on it and I don't have any blowby so I don't think that's an issue, injector balances are within the norms, I'm not blowing any smoke and regens are only lasting 20 min like normal. I checked a few days ago and I didn't see or feel any cracks on DPF or CAT so that's not an issue either I'm in Houston so I know the cold isn't a problem high 40s is the coldest it gets this time of year. I know people talk about active vs. passive regen could it be that she's trying to do an active regen?
 
#2 ·
what kind of miles on the truck? My 09 was done with the DPF about 225,000 miles and it was regening often cause it was borderline plugged , if you can get rid of the DPF put a nice tune in with EFI and you will think you got another new truck!
PS don't throw any parts away makes it hard to sell !!
 
#4 ·
What kind of loads do you carry, if any and do you take long trips, say 500 miles each way or longer?

No absolute proof, but I'm pretty sure that when I pulled my 12K trailer up and down big hills in the heat of summer, my truck ran better with regens further apart and when I didn't. When the engine works hard it seems to do better with the regen frequency.
 
#11 · (Edited)
I would have to agree with this statement.
I did an 8700km trip over the course of about a month last summer across Canada and back with my 13500lbs fifther in tow. Lots of wicked slopes in northern Ontario and of course in the mountains of BC. Regens are defiantly less frequent now and the trip also seems to have fixed up my sticky EGR valve. All in all the truck has run better since. These beasts love to work without a doubt.
 
#6 · (Edited)
Are you talking about removing the DPF and washing it out with a hose? Or trying to get some water thru the intake system, thru the combustion cylinders, out the exhaust, then to the DPF? This one works with normally aspirated gaso engines (to clean cylinder deposits) but I have no knowledge of it with a turbo diesel.

It's pretty darned flat around Houston so it will be hard to get the engine to work hard in a sustained basis on a trip vs a towing trip in the mountains of NM, AZ, CO, etc.

I would take a look at the pre- and post- dpf sensors and see if you can determine if they are working correctly. If they are NOT working correctly, that could be the cause of the regens.
 
#8 ·
#15 ·
I will never go with a after market cold air intake. It is a waste of dollars.
 
#9 ·
I think there are (at least) 2 distinct things you need to do:

1) determine the cause of the problem and the fix for the problem
2) get the DPF back to a 'clean' state

If you just wash the DPF, you MAY have accomplished #2, but it will come back dirty very soon and that's a lot of work for a short term gain. Also it it were that simple, that's how they would do the job commercially, and they don't.

The sensor is a $40 part at Rock Auto. Personally, I'd start there, and while you're installing it, check the wiring and tubing carefully. If the new sensor produces the same results, you have a different problem. If the sensor is the problem, #2 may soon be fixed by replacing the part.

I note the water in the fuel system may be a cause. Very high humidity in Houston, last time I checked. Maybe attack that problem to see if any help.

You didn't mention a DTC being set, but here is info on DTC P2463 from which you should glean some potentially important/helpful information :

DTC Descriptor

DTC P2463


  • Diesel Particulate Filter Soot Level Accumulation
Circuit/System Description

The particulates in the exhaust gases are collected by the diesel particulate filter (DPF). When the filter becomes saturated with particulates, they are incinerated by a regeneration process. The regeneration process increases the exhaust gas temperature, warming the diesel oxidation catalyst (DOC) first, then warming the DPF. The engine control module (ECM) monitors the system with inputs from two exhaust gas temperature (EGT) sensors 1 and 2 and an exhaust differential pressure sensor.

The ECM will command an active regeneration base on a calculated soot model. The soot model calculations are based on the following information:



  • Distance since last DPF regeneration
  • Fuel used since last DPF regeneration
  • Engine run time since last DPF regeneration
  • Exhaust differential pressure sensor values
If soot loading continues to increase it will eventually exceed a calibrated threshold and cause this diagnostic to run and fail.

Conditions for Running the DTC



  • The ignition is ON.
  • DTC P2463 runs continuously when the above condition is met.
Conditions for Setting the DTC



  • The ECM has determined that the soot level within the DPF has exceeded a calibrated threshold.
  • The condition exists for greater than 5 minutes.
Action Taken When the DTC Sets



  • DTC P2463 is a Type A DTC.
  • The ECM commands the engine control system to operate in Reduced Engine Power mode.
  • A message center or an indicator may display Reduced Engine Power.
  • The DPF regeneration is inhibited.
Conditions for Clearing the MIL/DTC

DTC P2463 is a Type A DTC.

Diagnostic Aids



  • A skewed or shifted exhaust differential pressure sensor will cause inaccuracies in the soot model and may cause this DTC to set.
  • Exhaust leaks in the exhaust system may cause inaccurate gas temperature sensor or exhaust differential pressure values causing this DTC to set.
  • Improperly installed or loose exhaust gas temperature (EGT) sensors 1 and 2 will cause inaccuracies in the soot model and cause this DTC to set.
  • Low engine compression may cause this DTC to set.
  • Corroded fuel injectors will have an inability to properly control regeneration temperatures and may cause this DTC to set.
  • Water in the fuel system will lower the energy of the fuel. Emulsified fuel will lower regeneration temperatures that may cause this DTC to set.
  • Not operating the vehicle under the proper conditions to perform a full and effective regeneration OR ignoring the Clean Exhaust Filter message may cause this DTC to set.
Special Tools



  • J 23738-A Mityvac
  • J 35555 Metal Mityvac
Circuit/System Verification



  1. Verify that DTCs P003A, P0047, P0048, P0087, P0101, P0201-P0208, P02A1, P02A5, P02A9, P02AD, P02B1, P02B5, P02B9, P02E0, P02E7-P02E9, P029D, P0234, P0299, P0300-P0308, P0401, P0402, P046C, P0545, P0546, P0698, P0699, P2032, P2033, P2269, P2453, or P2563 are not set.


  1. Engine running at a warm stabilized idle, observe the scan tool Particulate Filt. Pressure Variance parameter. The value should be between 0-3 kPa.
  2. Verify the following scan tool parameters:

    • Engine Run Time Since Last DPF Regeneration parameter-The value should be less than 22 hours.
    • Fuel Used Since Last DPF Regeneration parameter-The value should be less than 272 liters (71 gallons).
    • Distance Since Last DPF Regeneration parameter-The value should be less than 1,030 kilometers (640 miles) at sea level, or less than 772 kilometers (480 miles) when equal to or above 10,000 feet altitude.
    • If any of the parameters are greater than the specified range, perform a DPF Service Regeneration. Refer to Exhaust Particulate Filter Cleaning (LMM DPF Regeneration Enable) Exhaust Particulate Filter Cleaning (LMM DPF Service Regeneration).

  1. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.
Circuit/System Testing

Important:


  • Perform the Repair Verification after completing the Circuit/System Testing.
  • Select Capture Info to store the DTC information with the scan tool.
  • This DTC may require reviewing the Freeze Frame/Failure Records carefully for accurate diagnosis.
Visually inspect the exhaust differential pressure system for any of the following conditions:



  • Modifications
  • Damaged components
  • Bends or kinks
  • Loose or improperly installed components-Ensure the smaller diameter pressure line is connected to the front of the DPF and to the smaller port of the differential pressure sensor
  • Improperly routed differential pressure lines-The exhaust differential pressure line should have a continuous downward gradient from the sensor.

  1. Test for water in fuel contamination.
  2. Remove and visually inspect the flexible part of the exhaust differential pressure lines for internal restrictions.

    • If a condition is found, replace the exhaust differential pressure lines.

  1. Ignition ON, observe the scan tool EGR Position Sensor and Desired EGR Position parameters while commanding the EGR solenoid to 20 percent and 0 percent. The values should remain equal to or less than 3 percent of each other.

    • If greater than the specified range, replace the EGR valve and gaskets.

  1. Test the air induction system for leaks. Perform the Induction System Smoke Test in Charge Air Cooler Diagnosis (Full System Air Leak Test) Charge Air Cooler Diagnosis (Induction System Smoke Test) Charge Air Cooler Diagnosis (Charge Air Cooler Air Leak Test).
  2. Test the charge air cooler (CAC) for leaks. Perform the Full System Air Leak Test in Charge Air Cooler Diagnosis (Full System Air Leak Test) Charge Air Cooler Diagnosis (Induction System Smoke Test) Charge Air Cooler Diagnosis (Charge Air Cooler Air Leak Test).
  3. Test the fuel system for leaking, restricted or sticking fuel injectors, high fuel pressures, or high fuel injector flow rates.
  4. Ignition OFF, disconnect the harness connector at the exhaust differential pressure sensor.
  5. Ignition OFF for 90 seconds, test for less than 5 ohms between the low reference circuit terminal 1 and ground.

    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the ECM.

  1. Disconnect the harness connector X1 at the ECM.
  2. Test for less than 5 ohms on the differential pressure sensor circuits between the following terminals:

    • ECM X1 5-volt reference circuit terminal 14 to exhaust differential pressure sensor terminal 3.
    • ECM X1 signal circuit terminal 43 to exhaust differential pressure sensor terminal 2.
    • If greater than the specified range, repair the affected circuit for an open/high resistance.

  1. If all circuits, the exhaust system, and engine control system components test normal, test or replace the exhaust differential pressure sensor.
Component Testing

Important: You must perform the Circuit/System Testing in order to verify the integrity of the exhaust differential pressure sensor circuits before proceeding with Component Testing.



  1. Ignition OFF, remove the exhaust differential pressure sensor.
  2. Install a 3A fused jumper wire between 5-volt reference circuit terminal 3 and the corresponding terminal of the differential sensor. Install a jumper wire between the low reference terminal 1 of the sensor and ground.
  3. Connect a DMM between terminal 2 of the differential sensor and ground.
  4. Ignition ON, with the J 23738-A or J 35555 connected to the pressure sensor rear pressure port, slowly apply vacuum to the sensor while monitoring the voltage. The voltage should vary and transition smoothly without any spikes or dropouts.

    • If the voltage is erratic, replace the differential sensor.
 
#10 ·
2007.5 LMM I started Moding her a bit, put an AFE CAI(dry) to get that boost in MPGs but my DPF has been regening 3 times every 2 tanks instead of once every tank as she did before I put it on.
This is the easiest fix. Put the OEM intake back on.
 
#12 ·
Dont throw the baby out with bath water

I have had very good luck with Lucas Diesel Deep Clean. It was formulated by Lucas to put in the truck fleet. Can get it at any parts house


I had good luck getting my regin back to a normal frequency with it. :clap:


If it works great if not then you are no worse off.


two tanks in a row should clean you right up...if it is in fact cleanable:coolnana:
 
#13 ·
^ Interesting. The DPF cleaner (Liqui Moly) I used that you add to the fuel tank didn't fix my the regen issues.
 
#14 ·
The Lucas Diesel Deep Clean worked for me. It states on bottle that if the DPF is too far gone it cant fix it.


There is a break point where the filter is un fixable without removing it.
 
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