Jump to content

Recommended Posts

Posted

I have had so many problems with my LML Duramax engine that I stopped using it for long trips. With some emissions related problems I could go to 4 different dealers and the problem would not be fixed. Finally found a fifth dealer with a competent mechanic to fix the problems with the first visit.

 

There are problems with the sensors (NOx, DEF tank, DEF warmer, DEF pump, and with the wiring harness and with the programming that tries to diagnose problems. Three vacation trips in a row had to be cancelled due to emission controls problems. Very few mechanics have any ability to troubleshoot the problems and depend 100% on an error code to know where to start.

 

Many of the problems are bugs in the code, for example my truck went into limp mode and the error code indicated that the DEF tank was empty when it actually was 100% full. Only option was to drive at 55 mph a couple hundred miles back to my house. Driving on an interstate at 55mph and trying to safely merge with traffic, including the tractor trailer rigs are doing 70mph, is dangerous. I will never own a vehicle that puts myself and my passengers at risk with "limp modes". 

Posted
17 hours ago, Wintersun said:

I have had so many problems with my LML Duramax engine that I stopped using it for long trips. With some emissions related problems I could go to 4 different dealers and the problem would not be fixed. Finally found a fifth dealer with a competent mechanic to fix the problems with the first visit.

 

There are problems with the sensors (NOx, DEF tank, DEF warmer, DEF pump, and with the wiring harness and with the programming that tries to diagnose problems. Three vacation trips in a row had to be cancelled due to emission controls problems. Very few mechanics have any ability to troubleshoot the problems and depend 100% on an error code to know where to start.

 

Many of the problems are bugs in the code, for example my truck went into limp mode and the error code indicated that the DEF tank was empty when it actually was 100% full. Only option was to drive at 55 mph a couple hundred miles back to my house. Driving on an interstate at 55mph and trying to safely merge with traffic, including the tractor trailer rigs are doing 70mph, is dangerous. I will never own a vehicle that puts myself and my passengers at risk with "limp modes". 

What year was your LML?

 

 

Posted
On 8/14/2020 at 8:01 PM, ullose272 said:

 

Just had my first issue with my truck. Was pulling my trailer for about 2 hours 2000 lbs maybe, and noticed it was cutting out a little here and there. Came to a stop, sat there idleing for maybe 5 min. Then went to go again, all of a sudden, servce ESC light, service park brake light, and service emision system light, reduced power and was cutting out really bad and really bad shudder feeling. Ideas?

 

Sent from my SM-G973U using Tapatalk

 

 

 

Hi OP,

 

any updates regarding the issue?

Posted
Hi OP,
 
any updates regarding the issue?
Havent heard anything, it was 2 days ago they told me a engineer was coming out, i dont know how long that takes.

Sent from my SM-G973U using Tapatalk

Posted

 

On 9/11/2020 at 5:31 PM, ullose272 said:

Havent heard anything, it was 2 days ago they told me a engineer was coming out, i dont know how long that takes.

Sent from my SM-G973U using Tapatalk
 

Thanks for the update, I am in a similar situation.  350 or so miles in truck. Got a service transmission, service ESC, traction control, CEL. Dealership called and said maybe an electrical issue. Been there about a week and a half.

Posted
 
Thanks for the update, I am in a similar situation.  350 or so miles in truck. Got a service transmission, service ESC, traction control, CEL. Dealership called and said maybe an electrical issue. Been there about a week and a half.
Good luck!

Sent from my SM-G973U using Tapatalk

Posted
 
Thanks for the update, I am in a similar situation.  350 or so miles in truck. Got a service transmission, service ESC, traction control, CEL. Dealership called and said maybe an electrical issue. Been there about a week and a half.
Let us know if they figure it out

Sent from my SM-G973U using Tapatalk

Posted
On 9/15/2020 at 7:59 PM, ullose272 said:

Let us know if they figure it out

Sent from my SM-G973U using Tapatalk
 

Picked the truck up yesterday, service manager said they repositioned ground wires. There were multiple codes - P2122, C2a07, u0131, u0151, u0102, u0140, and u0146, they inspected the engine compartment wiring harness for rub through and connector terminal contact per doc 5568637, repositioned harness and secured per doc. They test drive multiple times and codes did not reset.

 

the drive home from dealership was uneventful as everything seemed to work fine.

Posted

Yeah sounds like assembly issues have not necessarily gone away. I wonder if better positioned strain relief on the harnesses and grounds are needed or just improper assembly to begin with? Did the engineer find this?

Good to hear your up and running again. Better tow with it ASAP to determine if the engine movement will make it return.

Posted

Picked the truck up yesterday, service manager said they repositioned ground wires. There were multiple codes - P2122, C2a07, u0131, u0151, u0102, u0140, and u0146, they inspected the engine compartment wiring harness for rub through and connector terminal contact per doc 5568637, repositioned harness and secured per doc. They test drive multiple times and codes did not reset.

 

the drive home from dealership was uneventful as everything seemed to work fine.

Thats awesome, hope its fixed, i guess my dealership is still waiting for the engineer to show up [emoji58]

Sent from my SM-G973U using Tapatalk

Posted

Hopefully they fixed it even though after all of your time and issues they couldnt even use the proper service manual document.  That doc# you referenced is information for harness chafing on the 2.7turbo. I imagine they found an issue with your harness about a foot and half from the ECM connectors where the engine harness runs over the alternator.  That may be where your problem lies as well ullose272, it's been showing up on a few trucks.

Posted

Update, engineer finally made it today, they spent most the day working on it. Ended up overnighting a engine and injector wiring harness. Hopefully have it back friday

Sent from my SM-G973U using Tapatalk

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Latest Articles

  • Posts

    • Monthly payment is only part of the equation. With today's prices and interest rates, I'd look at the total monthly cost: payment, insurance, registration, fuel, maintenance, and expected repairs. A vehicle that fits comfortably into your budget is usually the better choice than stretching for a higher trim. I've also kept my vehicles longer over the past few years. New cars have gotten expensive enough that driving one for 10+ years, while staying on top of maintenance, often ends up being the most cost-effective approach.
    • 10 Ford and Chevy engines proven to reach 300,000 miles   You may note a common 3K OCI on this list of gas motors. I skipped over the diesels. Dh'O. 
    • Thanks newdude!  By the time manual selection is needed, I'm probably too much of a control-freak to depend on the transmission sensing braking to activate automatic downshifting.  I would be anticipating the situation and already be manually downshifting.   This truck replaced a 2004.5 LLY diesel with the Allison 5-speed.  Putting it in T/H made noticeable differences (when the torque converter locked, upshift points, downshift behavior).  On this 2024 gasser with the 10L1000 I haven't been able to detect much, if any, difference.  Ok, I can never tell now when the torque converter locks up.  But I also don't notice differences in shifting.  For downhills, I've probably already manually downshifted by then anyway.  Since it's also more awkward (than the 2004.5) to engage/disengage I don't even bother.  Or maybe it doesn't really matter with just a 3k lb. camper in the bed?   Thanks also for the list of reasons the charging system might select various voltages.  However, what I am seeing doesn't fall into any of those categories.  It very definitely, and very consistently, rises after coasting/braking.  Maybe not immediately, but not very long after coasting/braking.  Very consistently drops voltage when no longer coasting/braking.  It might also be interacting with the camper battery charging (I might disconnect the camper and see if it changes the charging behavior).  I also need to recheck turning on headlights for when I want to force it to charge the camper.   Another JR, in June I converted the camper to LiFePO4.  Since it's not a good idea to try to charge lithiums directly using truck, I installed a Victron Orion XS DC-DC charger (which BTW is AMAZING!!).  Being cheap, I only had to buy that one item (besides the battery, of course) to do the conversion.  The camper OEM 120v battery charger (only 19 years old and works perfectly) and the truck feed the input to the DC-DC charger (not at the same time).  But I didn't want the camper charger feeding back to the truck so I kept the old separator.  I considered replacing the separator with a 30amp diode but that means more work and might add another 1/2 volt drop.  One thing that surprised me was the voltage drop over the long 10awg wire run, so I can only charge smoothly at 8 amps (because the DC-DC charger is completely configurable).  Another reason I don't want an added voltage drop with the diode.  I might also be a little lazy but all this work is being done under the sink with a small cabinet opening.    
    • apparently CA smog is (or at least was)  checking that the vehicle is using the oem and/or a ca smog approved tune, so I expect you'll fail inspection doing it.
    • yes, leaking exhaust will mess up o2 sensor readings, which in turn messes up fuel trims.
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...