CP4 High Pressure Fuel Pump Failure
CLICK HERE to purchase our LML CP4 High Pressure Fuel Pump Failure Kit
The 2011-2016 Duramax suffers from a high pressure fuel pump issue unique to this year range. Failure of this CP4 pump is usually catastrophic, causing instant contamination of the entire fuel system with metal particulates. Chances are, if you’re looking at this page, you’re well aware of the problem. Below we will discuss the reasons for this failure, how to diagnose a pump failure, and show you the parts you need to properly fix your vehicle.
Why Does it Fail?
The short answer: lack of lubricity. Lubricity is most commonly defined as the ability of a fluid to minimize the degree of friction between surfaces in relative motion under load conditions.
The CP4 injection pump creates higher pressures with less volume than its predecessor, the CP3 pump. Although this makes it a more efficient pump, the lack of volume creates a lack of lubrication since these pumps rely on the diesel fuel to act as a lubricant. In addition to the higher pressure and lower volume, the removal of sulfur from modern diesel fuel (Diesel #2 or Ultra-Low Sulfur Diesel) also destroys compounds that exist in the fuel naturally that would normally contribute to increased lubricity. Some fuel resellers mix lubricity-increasing additives into their fuel prior to sale, but this is not consistent and not well-regulated. Using a commercially available diesel fuel additive can be helpful, but cannot be guaranteed to prevent CP4 pump failure.
Diagnosing a Pump Failure
The LML and LGH CP4 pumps most commonly fail due to this lack of lubrication which causes internal metal parts (the drive cam, cam follower or pump piston, as well as the housing itself) to rub against each other and begin to shave off small metal particles. These particles are immediately distributed throughout the fuel system causing catastrophic failure. Some pumps actually seize up completely and burst the aluminum housing open as a result of this failure.
Using lubricity additives doesn’t guarantee that your pump won’t fail someday, so it’s important to know what steps to take when it happens to you.
If you’re experiencing a hard start or no start, or are getting the following trouble codes; P0087, P0088, P0191, or P128E, a pump failure could be the problem.
Remove the CP4 pump and then the fuel pressure regulator for inspection. If the body casing of the pump is cracked, as in the picture, or you find metallic debris on the fuel pressure regulator screen (pictured right) this is indicative of a pump failure.
Repairing Your Vehicle
GM Mandates that the below steps be performed:
• Replace: Pump, rails, injectors, all high pressure fuel lines, return lines, and fuel filter
• Clean and flush: All fuel chassis lines, filter pipes, and other engine mounted fuel system pipes (low pressure)
• Remove and clean/flush: Fuel tank and fuel sender
InjectorsDirect.com has put together complete repair solution for LML/LGH CP4 Pump failure using all OEM parts (pictured below.) Simply flushing the fuel system is inadequate, and could lead to residual contaminants in your fuel system. Contamination is the number one cause of repeat injector failure, and replacing all of the fuel system components is the only way to prevent recurring contamination issues.
We offer this kit in a few different convenient configurations to meet your needs, by default it includes:
- Bosch OEM New or Remanufactured LML Injectors (8)
- BOSCH® OEM New CP4 Pump (Updated housing, camshaft, roller tappets and gear pump)
- Bosch OEM New Fuel Rails (2)
- Bosch OEM New Return Line Assembly
- GM OEM New High Pressure Fuel Lines (Pump to rail, rail to rail & rails to injectors)
Click here for more information and to purchase the kit for your 2011-2016 Duramax LML Truck.
Click here for more information and to purchase the kit for your 2011-2016 Duramax LGH Truck or Van.
Give us a call or click today and get back on the road!
Could you please email me a copy of this LGHCP4 pump failure tech bulletin. Had to do a $10,000 replacement of fuel system on my 2014 gmc 3500 due to metal shavings. Trying to negotiate warranty with General Motors. Thank you for your assistance.
Good morning – We will send over a copy of the tech bulletin text right away. Thanks for stopping by!
Hey Brother, just bought a 2015 Chevy Silverado 2500. Only has 55000 miles on it. Would you please send me the tech bulletin? Do you think a formal recall will come about?
Thank you,
Robert
Hello Robert,
We have sent the bulletin your way. Unfortunately, we have not heard of any formal recall coming into effect. Thanks for stopping by!
I have a 2011 GMC Sierra 2500HD diesel LML. Read article in TrailerLife. Had no idea this was a problem. Have 82,00km on truck. Do you think GMC would cover this as a preventative measure, keeping good will of customer? Would you please send me the Technical Bulletin. Thank you very much. Now I am apprehensive about worthiness of my truck.
Thanks Again.
Derm Strong, in Canada
We will send that right over, Derm. We think it’s worth inquiring with GMC about preventative replacement if you’re under warranty, but we also sell just the pump for only $854.00 as a low cost alternative. https://www.injectorsdirect.com/product/duramax-lml-lgh-cp4-injector-pump/
I have a 2016 Duramax with 108,000 miles and the fuel pump had completely failed. Can someone send me the bulletin?
Hi Mark,
Sorry to hear about your truck. We will send a copy of the bulletin your way. If there is anything we can do to assist you with your truck please give us a call at 1-800-500-0980.
Please send me a copy of the SB for the Duramax CP4 failure. I have a 2015 that has not failed but I’m concerned it will fail at anytime. What suggestions do you have to be proactive to prevent the failure?
Hi Gary,
While we don’t have a service bulletin, I’d be happy to send over a copy of the blog post for you. Replacing the pump with the Cp4.2 or a CP3 conversion, running additive for increased lubricity, and using a FASS lift pump to increase the quality of the fuel being delivered and provide extra filtration are all recommended.
Hello looks like I’m having this problem I’ve been replacing everything and it won’t start. I’m actually on the road. As soon as I get home I’m gonna pull the regulator and pump and check it. If you can send me any kind of info I really appreciate it I know this is an old post thank you so much
Hi Jose – We have emailed you a copy of the article. Please let us know if you have any questions or need help with some replacement parts. Give us a call at 800-500-0980 if you have any questions!
Forgot to tell you I have the 2016 LML 6.6 thanks again
Hello – wondering if this is still active 2+ years later but it looks like I may have the same issue – 2012 2500hd . Any chance you would send a copy of the bulletin my way? Thanks in advance – Raymond
Hi Raymond – I have sent over a copy of the article for you. Please let me know if we can help you with anything else!
Can you send me the LGHCP4 bulletin, we have a 2106 Chevrolet 3500 that has hd the CP4 failure.
Hi Donna- No problem, we’ll send a copy of this article over now. Please let us know if we can be of any further assistance.
Hello,
My 2016 GMC 2500 6.6 with 43,000 miles is sitting at the dealership waiting on fuel system parts. Please send me bulletins or any other info you have about fuel system failure.
Thank you
Hello Tom, thank you for reaching out to us. I just emailed you over the requested tech bulletin. Please let me know if you need and further assistance. Greg B.
Hello, will you please send me a copy of that tech bulletin? Thank you!
Will do! Please let us know if you need anything else.
Jim, can you please send me a copy of the bulletin as well? My truck just died this morning and I fear I have the same problem.
Thanks, Leo
Hi Leo- Jim is out of the office today, but I’ve emailed you a copy of the article. Please feel free to give us a call if you have any questions or if we can help you with the parts to get your truck back on the road.
My 2011 GMC 6.6 has similar symptoms. Could you please send me a copy of the bulletin? Thanks
Will do Ken!
Please send me a copy of the tech Bulletin.
Thanks!
Hi Jeff- No problem, we sent a copy of the article to your email. Please let us know if you have any questions or if we can help you get your truck back on the road.
Jim, I think we may have the same problem as well. could you please send over any information on possible recalls.
Hi Aaron- Unfortunately we don’t have any additional information available regarding recalls, however we have sent a copy of the article to your email for reference. Please let us know if we can be of any further assistance.
needing a copy of the bulletin as well. . i have a 2016 silverado Duramax 2500 , with injector pump out. has been at Sunrise GMX dealership going on 2 months and they wont even return a damn phone call. still under warranty. please send asap. Isnt’ Morgan & Morgan have a class action suit against GM now ?
I’ll send over a copy of the post for you right away!
Could you send me a bulletin please
Hi Ryan- Sure, we sent it over via email. Please let us know if we can help!
Hey sir my name is Eric McCalphia. can you send me a copy of the tech bulletin. i just spent $11,475.10 because of catastrophic feul pump failure on my 2015 Duramax Deizel
Hi Eric,
We have emailed you a copy of the article. Please feel free to reach out to us if you need any help with replacement parts. Thanks!
Good morning, we are in the process of a full fuel system overhaul because of this issue. Please send me the technical bulletin as well.
Hi Tamara,
We have emailed you a copy of the article. Please feel free to reach out to us if you need any help with replacement parts. Thanks!
Hi can you send me a copy of the tech bulletin. My fuel pump failed on 2016 GMC.
Hello Gary, I will send a copy of that bulletin to your email. Thanks, Greg
do you still have a copy of the GM Technical bulletin for the injector pump issue described here.
Hi Bill- We Don’t have a GM bulletin to distribute, however we are happy to share a copy of our article as we have done for many other customers. We’ll email it to you right away, please let us know if you have any questions or if we can help with parts for your truck.
Please send me the bullitin concerning the fuel pressure pump failure. I bought a new 2015 High Country Duramax and just experienced the fuel pump failure. Dealer is still repairing the problem and I want all the information so I can at least fight a little!!!! Estimate for repair is 10 K.
Hello Pearl,
I am sorry to hear this, We sent a copy your way.
Hello
Would you be able to send me a copy of that tech bulletin for the CP4 injection pump. my 2015 3500 just went into the dealership for a repair.
Thank you
Justin
Hi Justin- Just sent it over, please let us know if we can help you with any parts to get your truck fixed.
Just curious if I could get a copy of the technical bulletin about the pump failure for the Chevy truck from 2011 to 2016? I have a friend that owns one of those trucks and I’d like to give it to her! ?
I’ll send a copy of it over for you.
Could you please send a copy of the bulletin to me as well?
Hi Josh, I am more than happy to do that for you! Let us know if you need anything else!
Better yet there has been several class action suites filed. Contact Morgan and Morgan
I would be interested to learn about the class action suit. What is it called and contact info.
Also the Tech bulletin on this as the dealer just quoted me 10k on my LML with 84K on the odo
We’ll send over a copy of the blog post right away for you. I’m afraid we don’t have any details on any pending legal action. Let us know if you have any other questions!
Can you please send me a copy too! Our truck just died on us this morning.
Thank you
Michelle
Hi Michelle- I’ve emailed a copy of the article, please let us know if we can help you out with the parts necessary for your repair. Thanks!
Could you email me a copy of the bulletin.
Thanks!
Hi John- We emailed a copy of the article over, please let us know if we can be of any further assistance!
Hello, Michael.
Could you please send me a copy of the bulletin? I have a 2015 Chevrolet 2500HD LTZ. Love this truck! Thank you.
Hi Gus – I’ve sent that over via email for you. Please let us know if you need anything else.
I have a 2016 Chev Duramax. Just cracked 75k. I would love to have a copy of the SB to reference when I request a pre-emptive replacement.
Hi Darrell. While we don’t have a service bulletin, we can send over a copy of our blog post here so you have a copy for reference.
Hello Jim , I have a 2015 that just failed , what have they done to update the pump ? Will you also send me a copy of the bulletin , The dealer is telling me that the pump is on back order and won’t be in for at least 10 days
I’ll send that right over. We have pumps (CP4 as well as CP3 conversion kits from S&S Deisel) in stock and ready to ship today!
I have a 2014 lml with 56k throwing a P0191 code and the dealer thinks it’s the co4 initially although the truck is running fine. 6 months out of warranty! Could you send the bulletin to me?
Any one having any luck wi gm covering this as it’s so widespread?
Hi Mike – we’ve sent over a copy for you – please let us know if you need any further assistance!
I have 2012 2500 Silverado with 126k. Have had Check engine light on for months but no loss of performance. Last week I was driving on freeway and the service Def system see owners manual NOW message came up with a Def light. It started counting down to limp mode. Before it had been erratic with its Def sensor, readings from no Def to full Def and everything in between. (Tank was actually full). I turned back and brought into first shop I could get to. They pulled a slew of codes:
P0087 HISTORY
P122E
P11B5 NOX
P11DC NOX
P202E ACTIVE
P2510
P122D
P205B ACTIVE
P2610
I took to another shop closer to the only place I could find a spot for my trailer. Took into another shop for 2nd opinion. They pulled same codes, ran a regen and I picked up truck because I had to move trailer again.
Now I have returned truck and gotten their diagnosis… It’s a minimum of 5500$ to replace fuel pump, change fuel filter, and perform service. If they find metal particles in the regulator then… I won’t write the words I’m saying out loud it’s family friendly forum. They can spend 2 hours labor getting to regulator and will tell me so I can decide what to do from there depending on if they find metal or not. The truck was a military vehicle made by world class trucks, and bought used so no hope of warranty. Is there any resource for assistance in this matter anyone can think of? I don’t have resources to fix the worst case scenario (or best) and am open to selling it. Is it possible to prove that seller cleared codes and sold knowing it had problems? Thanks for any help I am a newbie, this is my first (and likely LAST) diesel. I have already paid for weeks of lodging and am far from home. Not sure they can even finish before I have to move trailer again. It’s a nightmare, any advice appreciated.
Hi Trevor thanks for getting in contact with us! I have just emailed over a copy of this bulletin for your keeping and please let us know if there’s anything else we can do!
We are dealing with this same issue it is going to cost us 10k. We had no codes no signs of any problems just stopped. Can we have a copy hopefully they will have a recall and maybe get some of are money back.
Hi Kimmie,
I’ve emailed you a copy of the post for your records – in the meantime please don’t hesitate to reach out by phone at 800-500-0980 to discuss the options we have for trucks with failed CP4 pumps. We look forward to assisting you!
Jim
Could you please forward me a copy of the tech bulletin as well? My 2016, 85,000 miles, four months out of warranty, just experienced this with a $11,000 quote for repair. I am hoping/demanding warrantee be applied.
Hi Jeff,
I can email you a copy of this blog post, but please note there is no official TB from GM on this as far as we know. I’ll send you a copy of our post over now – feel free to give us a call at 800-500-0980 to discuss the options we have for your Duramax!
Can you please provide me with a copy of the bulletin as well. Our 2914 Chev 3500 is in the shop with an $11,000 repair bill for this very thing. Thank you!
Hello Sue, Thank you for reaching out to us. I will email you over the tech bulletin. Greg B.
Hi
I your opinion can you keep a stock cp4 living?? I.E. Lift pump, additive? Will the updated cp4 pump be a better swap for longevity? 2013 duramax 40000mls
Bob
Hi Robert- Yes, we definitely recommend running a fuel additive in every tank, this will add lubricity to your fuel and help your pump & injectors last longer. If your truck has the original CP4 you might consider upgrading to the updated CP4.2 as a precaution to avoid the catastrophic failure. We have the pump available here: https://www.injectorsdirect.com/product/duramax-lml-lgh-cp4-injector-pump/ Please let us know if you have any further questions.
Our 2016 GMC 1 ton Duramax has 70K miles without any issues. Over the weekend had this high PSI pump failure your referencing go out as per GM dealership. Thankfully GM will be covering this under powertrain warranty. Tough when dealers says “at least one week for needed repairs”
When we do get truck returned, what fuel additive would you recommend for us going forward? We are full time RVers towing a 5th wheel around the country.
Thanks for the informative article you have posted.
Hello Rick, Glad the article has been helpful for you. We run Stanadyne Performance in all of our trucks and have had a lot of good luck with it.
Hi, I just experienced the problem described above. This article helped me through the whole process, thank you. My truck is a 2016 2500 Duramax 91.5k on it. The dealer quoted the repair at 13k retail. Thankfully it was covered under the power warranty. I asked the obvious question- has the CP4 pump been improved? Their answer was yes. What do you all think?
Hi Marco- We’re glad to hear our article was helpful for you! Yes, the updated CP4.2 pump has proven to be much more reliable. We sell a lot of these kits and have not seen any failures to date. Please let us know if we can be of any further assistance.
I’m interested in the cp4.2 info and price also
Hi David, we’ve sent that information over via email for you. Please let us know if there is anything else we can assist you with!
My 2011 just died on me, thinking it’s the same problem as everyone else. It’s at the dealer now getting checked out. Can I get the bulletin also?
Hi Matthew- Sorry to hear this, we’ll send a copy of the article over right away. Please let us know if we can help you out with the parts to get your truck back on the road!
Please send me an email copy of your article on the cp4 pump issues..also, what replacement parts I need to replace the pump in my 2016 duramax 2500 ..also what lubricant you recommend..
Hi Ed- I just emailed over a copy of the article. Please feel free to give us a call at 1-800-500-0980, we would be happy to help!
My CP4 just went out on my ‘16. I asked mechanic at dealship if it was the same pump and he said he thought it was an updated pump. I don’t know. I thought the 16’s had the CP4.2 already.
I have a 2019 Duramax diesel with 1700 miles on it and the pump blowed up any answers for that
Hi Jeff- Sorry to hear this! Unlike the 2011-2016 LML the 2019 Duramax uses a Denso HP4 pump. Either way, your truck should definitely be covered under warranty. Let us know if we can be of any assistance.
GM void my warranty at 2200 miles at first changing the high pressure pump under warranty they said and then changing lift pump once the truck still didn’t start they said they void warranty and recommended I replaced all the parts including the ones they just replaced via technical service bulletins please help
Hi Dennis- Sorry to hear this, please let us know if we can help you with any parts to get your truck back on the road.
I have a 2012 that just had a new regulator installed and runs irregular sometimes..sounds like i have the same problem. I use the truck to tow a 5th wheel on weekends..thought it would be worthy..ive put over 5000 into it in last 6 months…very dissatisfied with gm. And thier diesel truck…
I have a 2013 model 3500 with 75,000 on it. Its over the 5 year time frame but mine blowed up. $10,900 repair. Can I get a copy of the tech bulletin?
Hi Brad- We’ll send over a copy of the tech bulletin text right away. Thanks for stopping by!
Good evening, My 2012 (133,000)just bit the dust on a long trip this past Friday and the repair shop that I have it at is a very good tech on Duramax and he is telling me that it’s a very strong possibility it will need the entire fuel system cleaned and most fuel components replaced on the engine. Are that any bulletins out that that could help me with some help on the warranty from GM or are they leaving all of us GM owners just hanging?
Hi Dan- Unfortunately we don’t have any solid info on GM’s willingness to complete these repairs at no charge when the vehicle isn’t under warranty, it seems to be decided on a case by case basis. Please let us know if you have any further questions or if we can help you get your truck back on the road.
2013 Duramax owner. Could you send the bulletin my way as well? I want to talk to my dealer. Thank you for this great info!
Hi Steve- No problem, we’ll send it over right away. Thanks!
I have a 2016 Duramax and the cost is supposed to be $13,000. Can I get a copy of the bulletin.
Hi Frank- No problem, we’ll send you a copy.
Thanks!
My 16’s CP4 just went up. 59,000 miles all stock. But it was covered under powertrain. How many miles did yours have ?
Since it would seem the failures are at random time or milage time frames is there an investigation into poor priming practices ie.air passing thru the linear spaces causing a dry ( no lubrication;fuel) condition that can be causative to failure.
Certain industrial application run bearing surfaces at high temperatures and possible higher bearing speeds with only pure water as coolant and lubricant with out failure . For the life of the systems.
Hello Francis, We see the common reason for the failure of the original CP4 Pump is mainly due to the lack of Lubricity, it is a combination of less volume in the CP4 Pump and the removal of sulfur from modern diesel fuel. This creates a very unfortunate circumstance for the original CP4 leading to catastrophic failure in most cases.
I have a 2015 could you send the tech bulletin also. Thank you
Good morning Brian – we will send that over right away!
Hi, I have a 2015 2500 GMC Duramax with 45,000 miles with no problems so far. I am presently using a fuel additive for lubrication. Can you send me a copy of the notice?
Thanks,
Dennis Van Wye
Hi Dennis- No problem, we’ll send a copy to your email. Please let us know if you have any further questions.
Tuned n deleted 12 3500. So far so good but would like tb sent if u could. Thank u in advance..
Hi Bruce- No problem, we’ll send a copy of this article over to you right away. Please let us know if you have any further questions.
I have a 2014 2500 gmc Sierra 2500hd 6.6 can I get a copy aswell
Will send that over right away!
I have a 2015 GMC 2500 with 140k just started to throw code po191 fuel rail pressure sensor. Would you please send me the tech notes on this issue please.
Hi Jeffrey- We’ve emailed you a copy of the article per your request, please let us know if we can help with any parts to get your truck back on the road!
I have 2013 GMC 2500, 102,000 miles. No problem so far. But this concerns me a lot! Options?
Hi Byron- You might consider upgrading your pump to the updated CP4.2 as a preventative measure. Feel free to give us a call if you’d like to discuss further.
Have a 2011 GMC 6.6lml 18500 miles on it no problems yet need copy of paper work want to up grade pump before it blows up should be recall on it they Kno what’s wrong with it
Hello Paul, We have emailed a copy of the article over to you, please let us know if you have any questions.
My 2013 had 114260 when it failed last week in lake havasu city stuck on road for 1hr in 115 degree heat truck shut off so quickly I couldn’t get it off the hwy completely very dangerous dealership wants 12900 to fix am currently in negotiations with gm
Randy, my 2016GMC blew up at 111,454 miles
What , if any assistance did you get from GMC ?
I am currently waiting for an answer.
Any ! Information would be helpful and appreciated
Thanks !
I have a 2011 GMC Savana LT 3500 Passenger Van with the LGH 6.6 Duramax. I currently have just under 35,000 miles. It has not done any heavy towing so far and is completely stock. It has been mostly used for hauling the family around for vacations and certain events. I have has no issues with the fuel system to date. Would it be wise to change out just the CP4 pump before I start to notice any issues?
Hi Mike- Yes, that would be a good idea. We have the updated CP4 pump in stock, let us know if we can help.
Hi,have a 2016 2500 6.6 with 32k on it and no issues so far.
What “exactly” has been improved on the cp4.2 pump..?
Thank you
I also would like a copy of the bulletin please. Thank you
Hi Scott- No problem, it’s on the way. Please let us know if you have any further questions.
Is GM going to put out a replacement warranty like they did with injectors on the lb7’s I have a 2013 with 107,000 and a 2015 with 40,000 no problems yet
Send me a copy please
Hi Wes – not sure on what GM will do, but I’ll get a copy of the bulletin sent over for you!
I have a 2016 6.6 liter how can I tell if I have the cp4 or the updated cp4.2 on my truck ? only have about 30,000 miles on it. Do you think that GMC will put out a recall, don’t see how they could afford it. Thanks for a great article. What about using the cp3 model?
Hi Mark- Are you able to read the Bosch P/N on the pump? If so, please let us know what it says & we can confirm for you. At this point we havent’t heard anything about a recall being proposed. Many customers run a CP3 conversion however that pump is not designed to deliver 2,000 bar of fuel pressure.
My 2016 durramax fuel pump just exploded with 127,000. Have had the truck since new and all highway mile. Truck is out of warranty and looking at least 10,000 to fix. Would you please what ever ammo you have that I could use against Chevy please. Any help is appreciated
Hi Nik- We just sent it to your email, please let us know if we can be of any further assistance.
I have a 2106 GMC Sierra 2500 HD with a duramax. I have 121k miles and the high pressure pump went out. The estimated cost of repairs $11,000. My truck has been in the shop for a month. They replaced the pump, it didn’t fix the problem. GMC Technical said that pump was bad also. They have another pump on order and we are being told it will be at least another week before they get the new pump. I’m losing faith in GMC. Their Customer Support has been worthless! Any help you can provide would be appreciated
Hi Danny- Sorry to hear they haven’t been able to get your truck repaired in a timely fashion, we have complete kits and pumps in stock & ready to ship today. Please let us know if we can help!
My pump just went out on my 2015 after 129,000 miles and got a $10k bill could also get some information I could use against GM?
Hi Alan – the only information we have is what’s published here – I’ll email you over a copy so you have it handy.
Hello I have the same issue 2015 2500HD, warranty is up and I’m at 170,000km. fuel pump failure. Dealer wants $17,500 after charging me $1600 to replace fuel filter and fuel filter housing. The price is ridiculous. Took took it from the dealer because I obviously can not afford that. Please send me any information that can help me and ammo against GM for this failure.
Hi Chris,
I’d be happy to send over a copy of this post for you to print out and have handy. If you can find a mechanic that will install parts you bring, we can certainly help you out with a pump failure kit for that LML Duramax – just give us a a call!
Can you send me a copy of the tech bulletin?
Hi Nik- We just sent it to your email, please let us know if we can be of any further assistance.
Hey we have a repair shop in Miami, we have a 2014 that appears to have a bad high pressure pump can u send me the bulletin everyone is asking about and the procedure u guys use to confirm the pump is the problem! Thank u in advance 954-***-****
Williamher**********
Hello William,
The best way to confirm you have a pump failure is by investigating the fuel system for metal debris. We would recommend starting at the Fuel Pressure Regulator on the Pump itself. If any metal debris is found present it is a key sign you have a failed CP4 Pump. Once the pump has failed it is HIGHLY recommended and necessary to replace all components in the fuel system from the CP4 Pump to the Injectors. Failure to do so can lead to repeated catsurphioc fuel system failure.
We will send a copy of the bulletin your way.
If you have any other questions please let us know!
I have a 2013 GMC hd2500 and from my vin number I have the LML.. I use it mainly for towing Fifth Wheel and want to discuss this with my dealership. I will also be starting to use a fuel additive. What about replacing the fuel pump with the older CP3 as per article in “Trailer Life”.
Can you also send me a copy of bulletin. Thank you
Hi Ken- Running an additive is highly recommended & can definitely prolong the life of your fuel system components. Many customers run a CP3 conversion however that pump was not originally designed to deliver 2,000 bar of fuel pressure. We’ve emailed you a copy of this document, please let us know if you have any other questions.
My 2011 GMC 3500 just had the pump failure, $10,000.00 bill, I added a FASS pump and separator system so should never see the problem again, can I get a copy of the bulletin please, I don’t anticipate any help from GM but worth a try.
HI Gord- IF the updated CP4.2 pump was installed you shouldn’t have any further issues, we’ll go ahead and email you a copy of the bulletin just in case.
Andrew please send me the tech bulletin. I have been dealing with intermittent stalling and sputtering for over a year since owning my 2015 GMC Duramax. Plus, I found the previous owner was dealing with the same issue, which was not on the car fax report. It’s been in the shop 8-10 times the last year and three attempts to fix the issue and nothing has worked. I truly believe I am dealing with a CP4 pump that is going bad. Plus, the GM service manager agrees but GM won’t approve the repair of the pump! Do you know what year GM starting using the CP4.2? Or do you have any advice that can help with getting GM to make the needed repairs? My truck has 86,000 miles and once it hits 100K it won’t be covered anymore. GM is screwing me!
Hi Shawn- Sorry to hear you’re having issues getting your truck repaired, they symptoms you’re having may or may not be pump related. Normally if the pump itself is bad the symptoms aren’t intermittent. Your 2015 most likely came from the factory with the updated pump, have you checked the fuel pressure regulator? In the meantime I’ve emailed you a copy of the bulletin per your request.
Could you please sent me the bulletin. I have a 2013
Hello Kurt,
We have sent our bulletin your way, thank you for stopping by.
I have a 2012 GMC Denali with only 35000 miles. No problems with fuel yet, but is there anything I can do now to prevent problems in future without spending $3,000 +?
Hello Jim, The 2 best things you can do will be, First order our CP4 Updated Pump and replace it before yours goes faulty, Secondly would recommend always using a fuel additive to increase lubricity. This will give you the most bang for your buck while extending the life of your fuel system.
Hi Jim- We recommend upgrading the fuel filter, please see: https://www.injectorsdirect.com/product-category/duramax/duramax-cat-fuel-filter-adapter/ Replacing the filter regularly as well as running a fuel additive in every tank. Some customers replace the CP4 with the updated CP4.2 as a precaution prior to catastrophic failure. We have the updated Bosch pump available for $599.99 here: https://www.injectorsdirect.com/product/duramax-lml-lgh-cp4-injector-pump/ Please let us know if you have any further questions.
Why is there a core charge on a NEW pump? Sounds like that salvage yard nonsense. There is no need for a core on a new or used part. Only purpose for a core is when purchasing a rebuilt part.
Hi Zachary,
Many of our vendors require us to return cores on new injectors and pumps. Receiving the cores back also allows us to subsidize our low prices on new products. Since most customers have no use for the core we are able to offer much better prices by getting the cores back. You can read more here: https://www.injectorsdirect.com/return-diesel-injector-cores/
I own a 2014 Chevy HD2500 with 41,000 miles. No problems so far but would greatly appreciate a copy of the Bosch CP4.1 tech bulletin referenced in your article.
Hello George, Just got a copy sent your way! Glad to hear the truck is running good, if you ever need anything in the future please let us know!
could i get a copy of the bulletin please
Hi Larry, I’ll email that over for you now. Feel free to give us a call at 800-500-0980 if you have any questions. Thanks!
Could you send a copy of the technical bulletin my way?
Thanks
Hello Jim, Of course! It’s on its way to you now. Let us know if there is anything else we can assist you with.
I have a 2015 3500 sew with 65000 miles can you send me the bulletin please
Hi Shaun, we’ve sent that information over via email for you. Please let us know if there is anything else we can assist you with!
2015 3500 Sierra duramax 55,000 miles just went out today. Could you send me the bulletin please.
Hello Greg, Thanks for reaching out to us, I will get the bulletin sent your way! If there is anything you need please let us know.
I had just ordered a complete kit this morning from you. Could you also please send me a copy of the service bulletin from GM about this issue with the CP4 pump failure? I will try to contact GM to try and get some assistance???
Thanks,SK
Hi Steve- No problem, we’ll send it over. Please let us know if you have any further questions.
I have a 2012 GMC SIERRA 3500hd with a 6.6L Duramax. It cranks but won’t start thing just died on me while driving. It’s been to 2 shop including the dealer. Been 3 weeks and they are still just exchanging parts. GM tech is saying I need 4 injectors on the left side. Not trying to buy $2400.00 worth of injectors and still have the same problem. Please advise me on my next move can’t afford 10k because they are guessing.
Hi Mr. Reid- Sorry to hear this. Do you know what diagnostic steps have been completed? We have 1/2 sets of injectors for the LML starting at $649.99, alternatively you could send your injectors in to us for testing to verify weather or not that is your problem. Feel free to give us a call at 1-800-500-0980 if you’d like to discuss further, we would be happy to help!
Thanks for the info on this post I had no idea about this. I have a 2016 with 35000 miles , should I just wait just before my 5 year powertrain is up and replace to the CP4.2 it seams like a good idea.
Hi Brad- Yes, that is what most customers do. Please let us know if we can help you with anything in the meantime.
Read all the comments, scary hope Gm steps up could I have a copy of the bulletin Thanks 2011 chevy with a hauler bed 81000 so far no problem heading to alaska next year any comments on the fass or sea dog lift pump and dual filters Richard
Hi Richard- We went ahead & emailed you a copy of the bulletin. Additional filtration is always a good idea, we also recommend running a fuel additive in every tank to add lubricity.
Hi Andrew, I just read my May 2019 issue of Trailer life Magazine. The article is called Diesel Heart Transplant. S&S Diesel Motorsport does an article about how the CP4.2 injection pump has garnered the reputation for catastrophic failure.I have a 2015 with just under 40,000 miles.They tell of converting a CP4.2 fuel injection pump to a S&S Diesel Motorsport CP3.
I was checking Duramax Diesel forums but then found you guys. Have you seen this article? Also, would you send me that tech. bulletin. Thanks, Greg
Hi Greg- We just sent a copy of the bulletin over to your email. The CP3 conversion is a good option, as the CP3 platform is much less prone to catastrophic failure. We have new Bosch® CP3 pumps in stock, let us know if we can help!
Jim,
Could I please get a copy of the bulletin you have referred to.
Thank you
Hi Randy- We’ve emailed a copy of the article over to you, please let us know if you have any questions.
Can you email me a copy of the tech bulletin as well. Looking at a 2013 duramax that’s never been touched.
Hi Larry – We sent the bulletin via email as requested for you. Please let us know if you have any other questions.
My pump failed at 36,000 miles and failed again at 78,000 miles. What in the heck!!! Thankfully I have a extended warranty.
Hi Erik- Good to hear you were able to get that covered under warranty! You might want to consider running a fuel additive to add lubricity, we use Stanadyne Performance & have great luck with it.
2015 GMC 2500 with LML 6.6 Turbo diesel and 55000 miles . i too am an Rver and the article in my Trailer Life magazine got my attention. Please forward me a copy of the bulletin….thanks.
Hi Tom – we have sent the bulletin via email as requested. Please let us know if you have any other questions.
I have a 2016 LGH 1 Ton Express. Could you please email me the tech bulletin as well?
Hi Forrest, we’ve sent that over as requested. Please let us know if you have any other questions.
We have now experienced this issue on a 2015 3500HD Duramax. The powertrain warranty expired on 4/30/19. I see “Special Coverage 29400” under my warranty details online with an expiration of 4/30/2024, but nothing for this bulletin. The local Chevy dealer has offered to pay for half of the total repair costs. Is this an offer we should accept, or is the tech bulletin something I can present and get full coverage without legal action? Thank you.
Hi James – This is a technical article we’ve put together to inform customers of a common issue with the LML CP4 – not an official Service Bulletin from Chevy. That being said, we are not in a position to offer legal advice with regard to your warranty coverage with Chevy. We’re happy to answer any questions you have regarding the parts!
Understood. Thank you.
Hi guys, my 2011 hd2500 injection pump blew up. Would love to get copy of tech report. $12,000 to fix I Hope gmc will step up.
Thanks
Sending it over now, please let us know if we can help!
Can you please email me the bulletin? 2015 GMC Sierra 2500HD 6.6 Duramax, 78000 miles……..injector pump went out today! Dealer wants $12000!!! Just got off phone with GMC ‘after hours’ warranty, said it would be covered under bumper to bumper-which expired already. I think it should be covered under drivetrain?! Any info you can email me would be great! Calling GMC again tomorrow & having it towed to a different dealer!
(we also tow a 5th wheel)
Hi Glenn- We just emailed it over. Hopefully they cover that for you under the powertrain warranty. If not please let us know, we’ll be here to help.
Please send a copy of report……my 2015 duramax injector pump went today! $12,000 to repair
Hi Jason- Its on the way, please let us know if we can help.
I have a 2015 Chevy hd 2500 Duramax diesel. While i was driving down the road going about 40 mph without any warning the engine just shut of. I tried to restart the motor but all it would do was turn over with no fire. I had a mechanic friend check it out and he said it was the high pressure pump that went out. Please send me a copy of your report. Thanks
Hi Malcolm- We just sent it over, please let us know if we can help!
hey my pump blew last month can I get a copy of it? 2012 3500 out of warranty but still!
Thanks for reaching out Christy! We have sent the bulletin – let us know if you have any questions.
We have a 2016 GMC 3500 HD with 50k miles on it. No problems yet and it’s still under warranty but we would like to not have any problems on the road as this truck is use for towing. Could you please send us the bulletin and also any recommendations you would do to keep failures at bay. We have not installed a lift pump either. Thanks for your help!
We have sent the bulletin Tony – please let us know if you have any questions.
I have a 2015 2500 Duramax diesel and it was serviced at the dealer 5 days ago, Yesterday going 75 MPH and it felt like it ran out of gas on the freeway. Towed it back to the dealer, They tell me that the Fuel pump “grenaded” Quoted 11K but because it was just there they cut it down to 6K. I understand after reading this and several law suits this is an issue but could it have been the service that caused this. They replaced the fuel filter?? Can you send me the bulletin please.
We just sent the bulletin over to you – let us know if you have any questions at all!
We have a 2016 Duramax, and currently stranded in Yuma AZ, after a haul to California from Florida, got a quote for 13k from a local dealer for this issue, can I have a copy bulletin plz
Hi Aaron- Sorry to hear your truck is down & the dealer is trying to charge you a fortune, please let us know if we can help! We’ll go ahead & email you a copy of this article in the meantime.
Have a Chevy 2013 LML Duramax with 77000 miles, no problem yet, but of course concerned. Please send tech bulletin on the high pressure pump in question. Also name of recommended fuel additive . Thanks
Hi Jerry- No problem, we just sent it over. In the meantime we recommend Stanadyne Performance Formula® which can be found here: https://www.injectorsdirect.com/product/stanadyne-performance-formula-diesel-fuel-additive/
In addition to the updated CP4.2 pump we also have a drop in CP3 conversion kit available, please feel free to give us a call if you’d ‘like to discuss further.
My 2013 GMC 2500 HD Duramax with 105000 miles just ate its CP4 pump. The usual fix, $10000.00 and the dealer sent me on my way.
Can you please send me the tech bulletin.
Thanks
Hi Loren- Sorry to hear this, we just emailed you a copy of this article for your reference.
2015 Duramax is down 115,000 injector pump sensor 3 weeks ago.1200…now a turbo… $4500 on turbo, should I do inj pump now
Hi Gerald- Replacing the CP4 as a precaution would not be a bad idea & may save you thousands of dollars compared to waiting until your original pump fails & damages your entire fuel system. Please let us know if we can help.
Hello, I have a 2015 GMC injestion pump failed @ 58k miles, dealer is refusing to warranty because the truck has a tuner. does this void the powertrain warranty?
Hi Bobby- Unfortunately it’s at the dealer’s discretion. Have you tried taking the truck to another dealer for a second opinion?
I’ve taken it to two different dealers. neither will honor warranty
Sorry to hear that, please let us know if we can help you with the parts necessary to get your truck back on the road.
You took it to the dealer with a tuner on it ???
can you please send me the tech bulletin?
Hi Bobby- No problem, we’ll send a copy of this article over now. Please let us know if we can be of any further assistance.
I have a 2011 that I am having fuel issues with, could I get this bulletin for diagnosing this please? I think mine is an electrical issue but it won’t hurt to check this out. When this happens, I get all sorts of things that happen intermittently and then it operates fine…
Hi Jonathan – we’ll send over a copy of the post via email. Please let us know if you need any further assistance!
Have a 2014 Chevy with 90000 miles, pump went out today. Please send a copy of the tech bulletin,negotiating with the dealer now. Five months out of warranty. Thanks
Hi Rick – we’ll send over a copy of this article to your email as requested. Please let us know if you need anything else!
copy of technical bulletin please
Have a 2012 Duramax in the shop right currently for repairs from the CP4 failure. Will you forward the Tech Bulletin to me please? Thank You!
Hi Nicole – we’ll email over a copy of this article for you. Please let me know if you have any other questions!
We Have a 2013 GMC Denali with 96,000 miles just installed a Fass 165 gal pump & been using a injector lube & fuel treatment for a few months.. Please send the tech Bulletin. We bought an extended factory warrenty, 7 years or 100,000 miles which will soon be up. Thanks Pete
Hi Pete- It’s on the way, please let us know if you have any questions.
I have a 2015 Duramax 2500 with 50k miles. No failure yet. I am reading lots about the pending “implosion”. A couple of suggestions include a S&S Diesel bypass to prevent metal from ruining the injectors. This won’t stop failure of the CP4 itself, but make the repair much less costly. Suggested cost for this is less than $1k. A CP4 replacement is estimated at around $4k (if the injectors not ruined) vs. catastrophic failure cost of $8 – 11K.
Any comments on this?
Also – how to tell for sure if I have a CP4 or CP4.2 and is a CP3 much better than a CP4.2?
Also, can you send me the Tech Bulletin mentioned in previous posts?
Thanks!