Diesel Place banner

1 - 20 of 52 Posts

·
Registered
Joined
·
30 Posts
Discussion Starter #1
P0420 three times, p220d, u029d, u029e, and p2610.

No mods and the truck still runs fine. I'm I'm the middle of a trip so any help as to what to look for. There is a permanent code but I have not tried to clear the others yet. I have a mode 6 scan tool but I dont know what is a normal reading for the nox sensor.

Help please???
 

·
Registered
Joined
·
2,513 Posts
When you reach your destination I would visit a GM dealer for testing.

Permanent or “latched” DTCs are defined as a confirmed fault code that is stored in non-volatile memory and currently commands the MIL to illuminate.
-This DTC prevents a vehicle from passing a Vehicle Inspection and Maintenance programs (I/M) test by disconnecting the battery or with the scan tool to clear the code prior to inspection.
-Permanent or “latched” DTCs can NOT be cleared by disconnecting the battery or with the scan tool prior to inspection.
-Only the On-Board Diagnostic (OBD) II system can erase a permanent fault code.
-The system must determine if the malfunction that caused the permanent fault code
to be stored is no longer present.

What is odd is your the only one in the LML section with P2610. It is caused by having the ignition on too long without the engine running during tuning.
Previous years this was a common code especially with the PPE tuner.

Definition of check engine code P220D:
Generic (Common for all car manufacturers):
Nitrogen oxides NOx sensor 2. bank 2 - supply voltage circuit malfunction.

The ECM uses two nitrogen oxide (NOx) sensors to control exhaust NOx levels.
-The NOx sensor measures the amount of NOx and oxygen in the exhaust system.
- NOx Sensor 1 is located at the outlet of the turbocharger. NOx Sensor 1 monitors engine-out NOx.
- NOx Sensor 2 is located in the canister between the selective catalytic reduction (SCR) and the diesel particulate filter (DPF). NOx Sensor 2 monitors NOx levels exiting the SCR.
-The ECM responds to changes in engine exhaust-out NOx levels.
-The ECM regulates the amount of DEF or reductant added by varying the reductant injector duty cycle.
NOx Sensor with Smart Module

Don’t know if you searched your codes. Just a few.
P0420
https://www.dieselplace.com/forum/63-gm-diesel-engines/365-duramax-fifth-generation-2011-2016-lml/979996-check-engine-light.html
https://www.dieselplace.com/forum/63-gm-diesel-engines/365-duramax-fifth-generation-2011-2016-lml/968980-p0420-code-cleaning-exhaust-filter-unable-solve.html
https://www.dieselplace.com/forum/63-gm-diesel-engines/365-duramax-fifth-generation-2011-2016-lml/966366-throwing-code.html
https://www.dieselplace.com/forum/63-gm-diesel-engines/365-duramax-fifth-generation-2011-2016-lml/939993-p0420-cleared-dealer-should-i-concerned.html
https://www.searchautoparts.com/motorage/technicians/undercar-service-repair/diesel-nox-sensor-technology?page=0,1

Your U**** codes are communication code.
U029D Lost Communication With NOX Sensor A
U029E Lost Communication With NOX Sensor B

The SCR system reduces nitrogen oxides (NOx) emissions by injecting a metered amount of DEF or reductant into the exhaust gas stream that enters the SCR catalyst.
-Within the SCR catalyst, the DEF reacts with the NOx to form nitrogen, carbon dioxide, and water vapor.
-Upstream and downstream NOx sensors provide the engine control module (ECM) with engine-out and tailpipe-out NOx levels.
-The ECM regulates the amount of DEF added by varying the reductant injector duty cycle in response to changes in engine-out NOx levels.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #3
Thank you for that information. Before I left for this trip, I did have a trailer light issue. I had turned the key to on, while taking care of a few bulbs. No check engine light at that time. The truck went through a regen just before I shut it off.The fumes were pretty strong driving on the highway. It never smelled that bad before.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #4
After turning off the check engine light the only code that remained was the p0420. I drove 180 miles and shortly after pulling off of the interstate, the check engine light came on and service exhaust system see owners manual. Then 99 miles to 65mph limit came on the msg center. Still no loss of power or driveability. Reading the codes again came back with nox voltage codes for a and b sensor, and communication loss codes for nox sensors and b. The p0420 was not there. It is at the dealer now in Oshkosh. Service writer stated that they follow gm protocol and replaced one sensor at a time. He also stated that the dpf had to be replaced on his last costumers truck , and that I should suspect that will be my case.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #5
Well they indeed replaced nbr 2 nox sensor and indeed failed after just under 100 miles. Good thing I was able to dump the trailer and gear off before taking it back to the same service center in Oshkosh.
Same codes: u029d u029e p0420 p220b these are pending and permanent codes.
Have to fly home for work so we will see how it goes in a couple of weeks.
 

·
Registered
Joined
·
2,834 Posts
How about a clogged def nozzle? This would make the regens useless. My son ran into this at the bus shop.
DEF is used whenever it is running.

For regen, LML adds diesel injected direct to the exhaust with the '9th' injector.
 

·
Registered
Joined
·
2,513 Posts
Have you replaced these yet?
GM Part No.:12671387 SENSOR, Fuel Tank Meter/Pump, SENSOR,NITROGEN OXIDE (POSITION 1)
GM Part No.:12671388 SENSOR, Fuel Tank Meter/Pump, SENSOR,NITROGEN OXIDE (POSITION 2)
 

·
Registered
Joined
·
30 Posts
Discussion Starter #10
You are correct. I read my sons note wrong. He mentioned the part is about $1000. I told him that during a regen, my avg fuel economy dropped to 8 mpg and when the regen finished, the avg fuel economy came up to 16 mpg.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #11
When the codes came back after the dealer had it for 4 days, I looked at it a little more myself. I found the x107 connector at the top left of the engine almost completely out of its mount. Two wires have rubbed through to the copper. These wires are either b10 and c10 or c1 and b1. Both are power and ground for now 1 and 2. I did tell the tech about it but I have not heard back. They have had the truck now for three more working days and they haven't gotten to my truck yet. We will see.
 

·
Vendor
Joined
·
9,675 Posts
I find that the P0420 code is often associated with the hydrocarbon injector (HCI) failing. Whether you call it the 9th injector, dosing injector or whatever they are reasonably priced and not overly difficult to replace. When they fail the temp does not get hot enough for a good regen. With the LML most any issue can be taken care of without component removal or replacement with the exception being the HCI and the temp sensors

I set up a nice Tech Tip regarding LML DPF regeneration: http://www.kennedydiesel.com/docs/LML Duramax DPF Regeneration.pdf
 

·
Registered
Joined
·
30 Posts
Discussion Starter #13
I have the truck back and drove it 120 miles yesterday. I will drive it back to Oshkosh for another 120 miles today. If all goes well, I will attempt to drive it on my 1200 mile trip next week.

The repairs were to the two wires that I found damaged and a new issue that popped up at the dealer, the reductant pump replacement. All I have now is a permanent p0420 code that I hope goes away after all the emissions monitors are happy. No pending codes and no cel.
 

·
Vendor
Joined
·
9,675 Posts
I have the truck back and drove it 120 miles yesterday. I will drive it back to Oshkosh for another 120 miles today. If all goes well, I will attempt to drive it on my 1200 mile trip next week.

The repairs were to the two wires that I found damaged and a new issue that popped up at the dealer, the reductant pump replacement. All I have now is a permanent p0420 code that I hope goes away after all the emissions monitors are happy. No pending codes and no cel.
Permanent P0420? That's not right. Dealer should be able to clear that. Follow that link I posted, study up on regen and monitor what is going on before hitting the road. I can ship the fix to most any place on the road, but I can't fix that 9th injector which I truly believe is the issue.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #15
I don't understand my mode 6 data. It is saying dpf regen 91% left the dealer at 67%. So it either got better or got worse with 240 miles. It was in passive mode the whole time. I'm wondering if it gets to 100% it will auto regen itself. Nox sensor 1 is in the 300's and nox sensor 1 is less the 100 cruising. What parameters should or could I look at for the 9th injector. I can see 3 get sensors and all are 480/500 cruising. Nbr 1 is always the warmest.
 

·
Registered
Joined
·
2,513 Posts
Fix your U**** communication codes first.

DTC P0420

Diagnostic Instructions

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic approach.
Diagnostic Procedure Instructions provide an overview of each diagnostic category.
DTC Descriptor

DTC P0420

Catalyst System Low Efficiency
Circuit/System Description

The diesel oxidation catalyst (DOC), main function is to control emissions of Non Methane Hydro Carbons (NMHC)and soluble organic fraction (SOF). The secondary function of the DOC is to assist with the diesel particulate filter (DPF) regeneration, by obtaining and sustaining the temperature necessary for regeneration. The engine control module (ECM) monitors the exhaust gas temperature (EGT) sensor 1 to determine if the operating temperature of the catalyst is achieved during a regeneration event.

When the ECM detects that the DOC is not reaching a pre-determined temperature during an active regeneration event this DTC fails.

Conditions for Running the DTC

The ECM must be commanding an active regeneration.
DTC P0420 runs once during an active regeneration event.
Conditions for Setting the DTC

The ECM determines that the DOC functionality has degraded below a calibrated threshold, during a regeneration event.
The condition exists for greater than 4.5 minutes.
Action Taken When the DTC Sets

DTC P0420 is a type B DTC.

Conditions for Clearing the DTC

DTC P0420 is a type B DTC.

Diagnostic Aids

The use of Off Road Red Dye Fuel or continuing use of non ultra low sulfur fuel may be a possible contributor to this DOC failure.
If EGT sensor 1, before the DPF, is slow to respond to exhaust gas temperature changes, or sticks in range, this DTC may set.
Circuit/System Verification

Verify that DTCs P003A, P0047, P0048, P0101, P0201-P0208, P02A1, P02A5, P02A9, P02AD, P02B1, P02B5, P02B9, P02E0, P02E7-P02E9, P029D, P0300-P0308, P0402, P046C, P0545, P0546, P2032, P2033 are not set.
If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
Verify that exhaust leaks do not exist before the DOC. Refer to Exhaust Leakage.
Circuit/System Testing

Important: Perform the Repair Verification after completing the Circuit/System Testing.

Inspect for the following conditions, which may cause a diesel oxidation converter (DOC) to degrade:
Off Road Fuel or Red Dye Fuel
Low quality B-20 fuel
Fuel Containing high sulfur content
Engine oil or coolant consumption
Leaking fuel injectors
Inspect the DOC for the following conditions:
Physical damage or alterations
Internal rattles caused by a damaged catalyst substrate
Exhaust leaks before or after the DOC.
If a condition is found, replace the DOC.
If all exhaust system inspections are normal, replace the DOC.
Repair Instructions

Catalytic Converter Replacement (6.6L)
Exhaust Particulate Filter Cleaning (LMM DPF Regeneration Enable) Exhaust Particulate Filter Cleaning (LMM DPF Service Regeneration) for Service Regeneration
 

·
Vendor
Joined
·
9,675 Posts
I don't understand my mode 6 data. It is saying dpf regen 91% left the dealer at 67%. So it either got better or got worse with 240 miles. It was in passive mode the whole time. I'm wondering if it gets to 100% it will auto regen itself. Nox sensor 1 is in the 300's and nox sensor 1 is less the 100 cruising. What parameters should or could I look at for the 9th injector. I can see 3 get sensors and all are 480/500 cruising. Nbr 1 is always the warmest.

You are over complicating this. My Tech Tip shows you what you need to monitor this in proper terms. Order this: Kennedy Diesel

Then I can help you track regen conditions as we'll be on the same wavelength.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #18
I took the truck for another ride today. After 20 miles the p0420 code came back. The truck started a regen about 100 miles after the p0420 came on. The nox sensor faults did not come back after the repair to the harness. I am wondering if I can drive 1200 home with the p0420 code with out speed and mile restrictions. The service exhaust system and 99 miles until 65mph has not returned since the nox sensor wire harness repair. When I get it home I can decide what to do with the truck.
 

·
Registered
Joined
·
6 Posts
My 2014 truck has been displaying that code for months without restricting speed. The only functionality I don't have is the ability to use remote start. If that is your only code you should be fine. Do you have a scan tool that will read your exhaust gas temps during a regen? Might be helpful to know why the code is triggered.
 

·
Registered
Joined
·
30 Posts
Discussion Starter #20
I can read temps . All are in the upper 400 to lower 500 when driving. When it was in regen all were 900=1000. I have not checked what they read cold yet. I will do that this morning. My scan tool can read most of the sensors. The one I dont understand is the dpf at 100%. The truck runs fine so I am assuming it is 100% efficiency not full. I am planning on driving it home on wednesday.
 
1 - 20 of 52 Posts
Top