Other Fuel System Problems of GMC Sierra 2500 - part 1

Gm duramax l5p diesel engine electrical connector for #4 fuel injector. This failure caused the diesel exhaust brake, which controls downhill speed, to disengage, extreme shaking of the vehicle, emissions system warning and speed limiting. This occurred while descending a steep grade while towing a 34 feet long, 10,000 pound trailer. This is a known issue with this diesel engine and documented in gm technical service bulletin 23-na-027. Inspection and repair at a gm dealership confirmed a known issue with the #4 injector pigtail connector caused by improper wire routing and interference wit the sound shield and valve cover heat shield this was a sudden failure of the #4 pigtail connector with no advance warning. In addition to violent shaking of the vehicle, multiple warnings on the dic indicating that the diesel brake was disengaged, the emission system had an issue, and speed would be limited.

See all problems of the 2018 GMC Sierra 2500 🔎.

I recently purchased my vehicle from big star dealership in baytown TX. At a little over 1000 miles I was towing a camper. The vehicle stalled, fuel pouring from engine. It was towed and repaired due to fuel pump failure. At a little over 3000 miles the vehicle would not start. Dealership initially said water contamination then changed it and said gasoline contamination and now they say def contamination. The vehicle stalling the first time almost caused me to wreck the vehicle.

The vehicle went into low power mode and said to pull over. As soon as that message appeared the next warning appeared and said to shift to neutral and pull over immediately and attempt to restart. The vehicle immediately shut off after second warning before having time to pull over from first message. I was able to pull most of the way off the road as the vehicle had shut off there was no power steering and had limited ability to steer the vehicle. This all happened without advance warning or any other warning that there was an issue while traveling at over 75mph. Vehicle would not restart and needed to be towed. Dealer stated it was a fule control module that was hard to get due to a recall. But that my vehicle was not part of that recall.

See all problems of the 2024 GMC Sierra 2500 🔎.

Component / system failure the exhaust system, specifically the exhaust manifolds and previously the egr system components, appear to have failed or malfunctioned, allowing exhaust gases to enter the passenger cabin. The dealer initially replaced the egr cooler diverter on December 23, 2025. However, the condition persisted. On February 3, 2026, cracked exhaust manifolds were identified by the dealership, and a major front-end teardown was advised to complete the repair. The vehicle is currently available for inspection upon request. ? how safety was put at risk the malfunction allowed exhaust gases, including carbon monoxide, to enter the passenger cabin during vehicle operation. Carbon monoxide readings inside the cabin reached up to 50 parts per million (ppm) while driving. Carbon monoxide is a toxic gas that can cause: •headaches •dizziness •impaired concentration •nausea •vision disturbances because carbon monoxide is odorless and colorless, this presents a significant safety risk, particularly at highway speeds where driver alertness is critical. The exposure occurred while operating the vehicle in normal driving conditions. This created a potential risk of driver impairment and increased risk of collision. ? has the problem been reproduced or confirmed? yes. The vehicle was presented to the dealership three times for the same exhaust intrusion concern: •December 16, 2025 •December 29, 2025 •February 3, 2026 during the February 3 visit, the dealership confirmed cracked exhaust manifolds requiring major disassembly for repair. The carbon monoxide readings were observed during vehicle operation. The exhaust odor and intrusion symptoms were consistently present following the first attempted repair. ? has the vehicle been inspected by manufacturer or others? the vehicle has been inspected by the authorized dealership on multiple occasions. Two manufacturer customer care cases were opened.

See all problems of the 2025 GMC Sierra 2500 🔎.

Cp4 injection pump failure while driving nearly causing vehicle collision.

See all problems of the 2016 GMC Sierra 2500 🔎.

My vehicles high pressure fuel pump failed causing the vehicle to shutoff while driving. In addition, due to the engine shutting down while driving, the power steering quit working causing me to not be able to steer the vehicle. Thank you.

The cp4 pump failed while driving causing vehicle to stall. Upon failure, lost power to steering. Luckily we were on an access road for a rest area and not yet on the interstate. This resulted in a 14. 5 thousand repair. No prior warning to pump failure. Gm has recently settled a class action related to this pumps failure and has never recalled trucks with this pump to avoid failure.

My 2016 GMC Sierra 2500 with a 6. 6-liter duramax diesel v8 engine suffered a complete engine shutdown—an issue that is both hazardous and expensive to repair. Fortunately, mine failed in a parking lot. No warning lights or symptoms were present. Failure is instantaneous and can occur any time rendering the vehicle inoperable on high-speed highways, intersections, etc. Failure always leaves vehicle occupants stranded, creating an unsafe and dangerous situation. My vehicle was towed to a GMC dealer. Repair costs could be as high as $15,000. The 6. 6-liter duramax diesel v8 engine is equipped with a bosch ‘cp4’ high-pressure fuel pump. These pumps are unreasonably fragile and prone to catastrophic failure causing instant contamination of the entire fuel system with metal shavings. General motors has agreed to pay $35 million to settle with owners following a class action lawsuit that accused the company of installing defective bosch cp4 high-pressure fuel pumps in certain Chevrolet and GMC pickup models. This action covered only owners in California, florida, illinois, iowa, new york, pennsylvania, or texas.

Replaced the exhaust tail pipe tip past the dpf and warning light came on after miles of driving. Vehicle was locked up and only able to drive 55 mph and there was a countdown to it dropping even lower. Dangerous to limit speed. This shouldn’t happen anyway with just changing out exhaust tailpipe. Very costly unnecessary repair.

Motor stopped dead while driving on a local interstate hwy. Was able to negotiate the truck out of traffic without crashing. Not an easy thing to do in speeding rush hour traffic. Had the truck towed to a reputable repair shop and discovered the cp4 fuel pump had failed and shattered throughout the fuel system. Repairs in the amount of $13,520. 30 incurred to get the truck back in service. The attached invoice includes $167. 87 for other maintenance not related to the cp4 fuel pump repair. This is a known problem and safely hazard. A class action suit settlement is related to the cp4 fuel pump against multiple truck manufacturers. . Read more...

When I am driving in town I have an indication message that comes up and says engine power reduced.

See all problems of the 2009 GMC Sierra 2500 🔎.

I leased this vehicle on may 17, 2024, expecting it to function as intended. Instead, within months, it suffered recurring and escalating failures that have rendered it unsafe and unusable. January 7, 2025, I brought the truck to gates GMC for routine service and reported that it had lunged forward by approximately 2 to 2. 5 feet while shifting into park. Additionally, it exhibited irregular acceleration and rough down shifting in lower gears. I also communicated the check engine light has come on and gone off on the dashboard over the past week a few times without receiving any information on the app. At this January 7th visit, gm performed recall n242435631, supposedly addressing a known battery drain defect that caused total vehicle shutdowns. On January 24, 2025, I started the truck and was immediately overwhelmed by an intense chemical odor coming through the ventilation system. January 31 – February 1, 2025 – erratic engine warning lights & diagnostic failures on January 31, 2025, at 5:28 pm, on this key cycle the check engine light illuminated but failed to register in the gm app. On the next key cycle, the warning disappeared. The following morning, February 1, 2025, at 10:26 am, the check engine light appeared on the first key cycle before disappearing on the second key cycle. The onboard diagnostics system failed to log or retain these warnings. On February 7, 2025, the vehicle suffered a complete electrical failure. No electronic function whatsoever. Roadside assistance attempted to jump-start the truck using a high-powered jump pack, but it remained inoperable. A Ford super duty and jump pack were needed to force start the truck. February 10, 2025 the truck suffered another total electrical failure and required towing to gates GMC. The app indicated the brake system, anti-lock braking system, emissions system (specifically the exhaust system), and power train requiring service. My truck is at gates GMC and was drawing 90 milliamps opposed to 40.

After taking my truck in for recall fixes. I received a message on my screen saying that I had 94 miles until I was limited to 65 mph. It said check def system. After taking it in the dealership charged me to fix the computer. Known defect yet they charge for it.

See all problems of the 2022 GMC Sierra 2500 🔎.

The contact owns a 2013 GMC Sierra 2500. The contact stated while driving 60 mph, the vehicle stalled. There was no warning light illuminated. The contact was able to coast to the side of the road, where a mobile independent mechanic diagnosed that the fuel pump had failed. The mechanic determined that the entire fuel system assembly needed to be replaced. The vehicle was not repaired. The vehicle was then towed to an unknown dealer but was not diagnosed or repaired. The vehicle was currently being towed to the residence. The manufacturer was notified of the failure and informed the contact that the repair could not be covered because the VIN was not included in a related recall and the vehicle was not covered under warranty. The failure mileage was approximately 206,000.

See all problems of the 2013 GMC Sierra 2500 🔎.

The fuel pump power control module failed. The part is currently at the nearby chevy dealership. The safety of myself and two passengers were compromised when the struck suddenly lost acceleration, then shortly after lost engine idle. This occurred while vehicle was in motion on a main highway leaving us stranded on the highway and no warning or indication was given. The problem was confirmed by a dealer. The vehicle and component were inspected by the dealership. There were no warning lamps, messages or symptoms prior to the part failure.

See all problems of the 2019 GMC Sierra 2500 🔎.

My high pressure fuel pump, cp4, went out with no warning while driving causing me to lose power. Was able to bring truck to stop safely but was stuck in middle of roadway.

2022 GMC siera 2500 diesel have code p20b9 and tailgate opening by itself.

The pigtails to the injectors are prone to failure. The vehicle without warning throws multiple codes and immediately limits power and speed while shaking. This can cause a dangerous driving situation. This is a known problem and is on many online forums as a common failure. The repair shop gets so many of these that they were able to diagnose the issue over the phone and noted that it usually happens around the 200k mile mark. However many reported this as an issue while under warranty. The issue is with the metal connector material being prone to failure and arcing.

See all problems of the 2017 GMC Sierra 2500 🔎.

Truck has a cp4 injection pump and they go bad and cost $15,000-$20,000 to repair and if that happens I owe money on the truck and would have to get a loan or figure something out and still have to make a payment on something I can’t even drive! they need to recall it and swap them out to a cp3 and be done with it. Why wait until it cost 10s of thousands of dollars when they can get it done for $3,500 at the most?.

See all problems of the 2015 GMC Sierra 2500 🔎.

Truck is a diesel. Fuel pump blew up and died in the middle of the street. Now I'm being told the fuel system needs completely re done and will cost me 10g. I also found a lawsuit for this issue as well.

See all problems of the 2012 GMC Sierra 2500 🔎.

While driving down the highway at 60 mph, the truck stumbled then completely died. After coasting to a stop truck would not restart. Towed to a repair shop to find out the bosch cp 4 fuel pump exploded and contaminated the whole fuel system with metal shavings. A very expensive and lengthy repair. Gm has known there is issues with these parts, but has failed to recall and fails to cover repair costs. Other manufacturers using the same part have issued recalls. While I was able to safely the get vehicle to the side of the road, the failure could’ve resulted in an accident causing personal injury or property damage.

The connectors to the fuel pump have failed causing the truck to mechanically fail and not operate. This is a common problem per the diesel technician who diagnosed our truck and in his opinion should not be happening as often as it does. It’s specifically the cylinder 4 injector control circuit and diagnosis states the pins are corroded.

While pulling 35' 5th wheel down freeway, a message appeared in instrument panel telling me the fuel filter was at 0 percent and was going into low power mode. There happend to be an offramp there that I was able to get off the freeway. While making the turn on the offramp the truck died. I pulled over as far as I could whie coasting with no power steering or brakes, leaving truck & trailer partially blocking the offramp. Unable to start the vehicle, I immediatly contacted onstar and they dispatched the chp & tow truck. When chp arrived he asked when tow truck would be there. Without being able to confirm exactly, and due to safety concerns because of blocking the offramp, he called his own tow truck (rons towing) and forced me to move vehicle to safe location. The issue ended up being the injector fuel pump (cp4) that gm was well aware of going out and sending metal fragments throughout the fuel system. I've been told the pump was made in china and not to gm standards. The vehicle has been repaired, all work was covered under extended warrenty, this all could have been avoided if gm would have replaced the faulty fuel pump under recall. Had this happened 100 miles further on our trip we would have been going over pacheco pass in calif. Could have been a total disaster had we been going down the other side with no power steering & no power brakes pulling a 12,000 lb trailer in the dark.

Constant issues with glow plug failures, fuel rail failure, fuel pressure failure. Truck has been in the GMC service regarding these issues constantly for the last year with a total of five repairs and replacement of glow plugs with releaning learning new plugs and now the 6th return to the shop they’re tearing down the fuel system. Malfunction and engine light consistently come on with the same occurring problems generating from the fuel system and glow plugs. Fuel mileage is absolutely terrible and lose of power hazardous to safety!!! GMC has issued an extended warranty for 15 years and 150,000 miles, but cant and hasn’t found a repair for vehicle and just replaces the glow plugs just so they can fail again and again!!! they need to replace everything that needs to be done and if no fix they need lemon law the vehicle. This is ridiculous going back to the shop every two weeks I have my truck in the shop for a month to get it back, to put it back in the shop two weeks later, to have it back in the shop for a month. Since this start 17months ago I’ve only been able to put less then 7000 miles on the vehicle because GMC constantly has the truck! the is ridiculous when you’re paying $800 a month for your payment and insurance on your vehicle that you can’t drive because the manufacturer is constantly having to repair and replace the same thing over and over again.

The def heater gm part#84162464 has broken on my truck. There are many owners with the same problem on their duramax diesels. This has been an issue since def tanks were mandated by the federal government. The replacement cost is estimated to be $2000. From my local dealership. The truck had 50,000 miles on it when the heater first started working intermittently. I'm reporting this so it can be logged in as another incident for failing, poorly engineered parts.

On 4/12/22, we were towing our 32ft trailer with putt 2011 diesel GMC sierra truck to big bear lake which is in the san bernardino mountains in a two way winding highway. Upon making a somewhat sharp turn up a steep uphill, our accelerator went out. We had my mother in law, our two kids and dog in the vehicle at the time. We were able to get a speed of about 5-10mph to get a turn out and turn back around. We had no reception to call for help. The accelerator gave out shortly after but we were able to ride the decline to the bottom of the mountain and as soon as we were getting to the bottom, the engine turned off on us. Although it was still a two way highway, thankfully there was an emergency lane where we were able to park and where we were able to get very limited reception to call aaa (tow truck). There were vehicle speeding past us in high rates of speed. Because we needed a specialty tow truck given the towing of the truck/trailer, we knew it would take quite a while in the mountains for a driver to get to us. Temperatures at night in this area can get to 10-20 degrees. Five hours later at 11pm we were towed home. Upon towing the truck and trailer home, we were made aware of the reason the truck broke down through a diesel mechanic, which was cp4 fuel pump failure. Upon learning this and going online, we found out this is common for this truck with the cp4 fuel pump. We also found that other companies have made recalls, eg. Dodge but GMC/chevy has not. This is obviously a safety issue that could have been catastrophic for myself, my kids and family and am wondering why there hasn’t already been a recall through GMC. Please let me know what our recourse is or if you have any questions.

See all problems of the 2011 GMC Sierra 2500 🔎.

2014 Sierra 2500hd sn (1gt120c83ef176464) leaving on vacation towing camper with family bosch cp4 fuel pump issue left me stranded on a hwy 9 just outside clinton, ar which is a 2 lane hwy with no shoulder. The vehicle gave me no prior warning, dash board suddenly read power restricted followed immediately with complete power loss as I reached to top of hill. I was forced to steer and brake the truck and camper with no power, down the hill to prevent vehicles from passing at crest of hill. This left me and my family and numerous other drivers in a very dangerous situation as cars tried to pass. I had to open the hood and try to determine what was going on. I directed traffic until a van buren county, ar sherriff’s deputy arrived scolding me to get the truck and trailer out of the highway. I was forced to unhook trailer in middle of hwy and leave it. All the while, vehicles passing in danger of head on collision because there was only one officer directing both sides of traffic. Gm is aware of this issue that cost me $10336 at gm dealership where repaired. Had I been aware, I would have had this replaced this bosch cp4 part to prevent the unsafe conditions I encountered. One message came on dash, restricted power, and I was powerless. Final bill stated “found injection pump has come apart internally and has put metal through the system. ” internet search stated: according to injectorsdirect. Com, the 2011-2016 duramax suffers from a high pressure fuel pump issue unique to this year-range model. Failure of this cp4 pump is usually catastrophic, causing metal particulates to contaminate the entire fuel system. Please help this from happening to another person. These trucks are advertised showing families pulling campers traveling through mountains. That is exactly what my family was doing. I have additional documentation if needed.

See all problems of the 2014 GMC Sierra 2500 🔎.

Faulty pigtail connector for fule injectors. Cause the vehicle to shut down even while going down the highway possibly causing injury by immediate deceleration wich could cause an accident. For me on this vehicle I’ve had this happen three times and it has cost me anywhere from $800 to 1000 per injector especially if damage is done to one of the fuel injectors.

The vehicle experienced a catastrophic failure of the fuel pump while towing a horse trailer on a busy state highway. This was a major safety risk because the vehicle gave no warning before it just stop working. It was a miracle we were able to coast off the highway into a wide spot that was able to accommodate both the truck and the horse trailer. The truck only has 77,000 miles and we are being told that none of the repair is covered under warranty. We were also told that the fuel pump has completely contaminated the entire fuel systems, including the injectors so everything must be replaced. The quote we received from the dealership for this massive repair is $12,208. 59. No warning lamps, messages or other symptoms occurred until the truck died. Once the truck died, it could not be restarted and then began displaying a code that said the fuel filter needed to be replaced.

Engine stalled due to fuel pump failure. Dealer had to replace entire fuel system.

Def tank system failure. Vehicle is under warranty, 18 months old, (purchased 08/20) with 20,000 miles. 6 weeks ago I took to dealer who informed me that there are no def tanks available and don't know when they will be available. This is a hazard: if I am on a trip and the system shuts off I could be stranded anywhere with the reduced speed that the def system creates. If this system is designed to shut off (with warning) there should be ample supplies at all GMC dealers for repair. If there aren't ample supplies the system should not shut the truck down. This is a safety hazard that is preventable!.

See all problems of the 2020 GMC Sierra 2500 🔎.

Vehicle shows on the dash readout that the truck must keep going to clean out exhaust keep driving, then comes to a slowdown, and on a slight hill stops. When you shut it off, and start it up again, it goes about a mile, states the same thing on the dash panel, then starts to slow down, I was in the desert of new mexico, had left flagstaff, az. An hour before this started happening. I had no previous warning. Took 6 hours to reach a GMC service center. Usually takes 2 hours to reach the same town. Cortez, colorado. They could not help me, they had to referred me to a service center in town, that put me on his machine, and made the vehicle heat up, run hot, and exhaust itself for two hours, this got me to my home in monte vista, CO. Then no further problems until about a month later I started getting the same messages, I took it to a service center in ar. Where he forced the vehicle to get hot, exhaust itself for four and a half hours, to clean it out, and clear my dash pannel.

I have a 2013 GMC sierra, purchased new in 2012, has approximately 35,000 miles. The check engine light came on while driving and suddenly another light came on. Then a third light came on claiming poor engine fluid quality. I immediately stopped at an auto parts store and put def fluid in the pickup and continued to drive thinking the lights would go out, but instead a warning was flashing on the dash that says after so many miles the truck will be slowed down. We started getting nervous because we were driving on the highway and if the truck suddenly slows down whilst driving in highspeed traffic, our slower vehicle would potentially cause a collision and put us and others in harms way. In reading your own safety site, there is a recall on the vehicle regarding faulty airbags, so it could be even worse! in our investigations of our current issue, we have found that there was a lawsuit from 2019 against gm and their faulty fuel system with their trucks. . Read more...

While driving to work with my workers and I on hwy going 70 mph pickup just turned off on me and no longer started up. Took to mechanic and said it was the bosch cp4 failure. Metal debris flooded our entire high-pressure fuel system. Had to get replacement of fuel lines, fuel rails, pump and injectors and the removal/flushing of the fuel tank. Our total repair is over $12,000. Which we don't have. Mechanic just finished repairing it after 11 month's but we don't have the $ to get it out from shop.

While exiting off ramp of the interstate my truck just completely shut down. After several towing bills to different mechanics to verify the problem, it was the cp4 pump system ! over $13000 in repairs , towing , and rental fees.