2018 GMC Sierra 1500 Driver assistance Problems

ENGINE FAILURE, 5/3/22, 23,987 MILES, ALL LIFTERS WAS REPLACED UNDER WARRANTY, ENGINE FAILURE, 7/6/26, 46004 MILES, TOOK TRUCK IN FOR OIL CHANGE AND WHEN RETURNED HAD A TICKING NOISE. DEALERSHIP NOTIFIED ME THAT CAMSHAFT ISSUES AND METAL DETECTED IN OIL. ENGINE NEEDS REPLACED. 6.2 V8 2018. TURPIN MOTORS, GENESEO, IL HAS DONE ALL SERIVCE ON TRUCK. NO WARNING LIGHTS OR CODES. VEHICLE IS IN MY GARAGE AND AVAILABLE FOR INSPECTION. I OPENED CASE WITH GM #105652237. DEALERSHIP OPENED CASE ON GM PORTAL ALSO. RESPONSE FROM GM IS THAT TRUCK IS OUT OF WARRANTY

NHTSA ID

11754023

Incident

Jul 6, 2026

I am the original owner of a 2018 GMC Sierra 1500 with the 6.2L L86 engine and 8-speed 8L90 transmission. I began experiencing severe transmission shuddering and harsh shifting, especially at lower speeds or under light acceleration. When the issue occurs, I press the gas and the engine revs up to 6,000 RPM without reaching 20 MPH, making it extremely difficult — and dangerous — to merge into traffic or cross intersections. This issue has worsened over time and is now a critical safety concern, especially with children in the vehicle. I have researched this issue and found that many owners report the same transmission defect, and there is an open class action lawsuit and a GM Technical Service Bulletin (TSB #18-NA-355) describing the exact symptoms. The vehicle has become unsafe to drive. GMC should issue a recall or mandatory repair program for this known defect before someone is injured or killed.

NHTSA ID

11665900

Incident

Jun 7, 2025

While driving my truck and making low speed turns the dashboard (including center console) cuts off, along with my power steering. The truck has also shut off completely making u-turns causing me to almost crash. This also happened while driving around 60mph on the freeway, the entire dashboard went out, loss of steering, and truck shut off, almost causing an accident. When it does happen, it will cut out in 1 second intervals and steering will work again for 2 seconds then cut out again for 1 second, this causing me to stall. There are no check engine lights, or service lights that stay on. However, I will get a message stating: You are memory setting 3 in the system (wording may be different). In some cases the stabilitrak light will come on, the park assist warning stating it shut off comes on dash, and trailer break. I have a full service AUL warranty and had vehicle checked at certified dealership and no codes were recorded. I replaced battery and the problem is still happening. This is unsafe and should be part of the previous recall as my symptoms are the same exact symptoms as the other 2018 recall.

NHTSA ID

11652605

Incident

Apr 2, 2025

Drive train:The truck suddenly lurches forward as I'm accelerating and after I've stopped. It's very scary to stop behind a vehicle and suddenly lurch forward. Thankfully, I don't stop too close to another vehicle. The truck also shudders and experiences significant delays in acceleration after coming to a stop and going again. Automatic Emergency Braking: the automatic emergency braking system spontaneously brakes as I'm driving when there is nothing in front of me. Thankfully, nobody has been following behind me when this happens yet. I had to turn the automatic braking system off in order to avoid being hit.

NHTSA ID

11600427

Incident

Mar 1, 2024

2018 gmc Seirra 1500 8 speed transmission. Making unsafe conditions while driving transmission tends to make hard shifts, jerks, hesitation when moved into gear, gets worse when stopping momentarily at stop lights and then trying to accelerate vehicle will not move. Makes hard shift and jerks then will accelerate in an unsafe manner.

NHTSA ID

11587154

Incident

Jan 10, 2024

Braking vehicle will cause brake pedal to vibrate and become soft while pressing it and requires more effort to stop vehicle. Service brake assist light laminates on info system. I know there is a recall for this currently but my vehicle is not listed for this all though i have the same issues. Recall is N202300860.

NHTSA ID

11502581

Incident

Dec 5, 2022

THE SPEED OF THE TRUCK WILL NOT INCREASE. THE RPMS GOES REALLY HIGH AND THE TRUCK WILL NOT MOVE INTO THE NEXT GEAR. THE REAR END OF TRUCK VIBRATES. I TOOK THIS TO THE DEALER AND WAS TOLD IT IS THE TRANSMISSION FLUID IS FAULTY. THE CHECK ENGINE LIGHT DOES COME ON. I DID NOT HAVE THE NEW TRANSMISSION FLUID CHANGED BECAUSE DEALER SAID IS COST $300 FOR THE FLUID AND $100 FOR THE LABOR AND $168 FOR THE DIAGNOSTICS. SO I STILL HAVE THE SAME PROBLEM. ALSO TOLD YOU CAN NOT PURCHASE THIS TRANSMISSION FLUID NO WHERE BUT GMC.

NHTSA ID

11477417

Incident

Jul 25, 2022

The light in the dashboard gose dark and it gives me a warning collision alert and the tiers they spin out of control when turning or when I I’m driving I think it’s the tiers they have a lot of tread still…

NHTSA ID

11472803

Incident

Jan 1, 2022

Driver Assist-Lane Keeping Assist-Forward Collision Warning-Automatic Emergency Breaking Life Threatening When System Fails and is Intermittent . Vehicle has been said to be dangerous to drive by GM Tech/Can cause life threatening conditions. Fault has been confirmed by Dealership. WARNING LAMP> "SERVICE DRIVER ASSIST SYSTEM" Friday 3 December 2021 at approximately 21340 miles.

NHTSA ID

11443233

Incident

Dec 3, 2021

The truck displayed warning lights for ABS, traction control, trailer brakes, and front park assist. Additionally speed control (cruise) did not function. This presented a safety issue. I took to dealer asap. They repaired by replacing left rear wheel speed sensor. Cost about $216. Appears to work correctly at this time.

NHTSA ID

11441201

Incident

Nov 11, 2021

Vehicle suddenly went into Reduced Engine Power while driving in heavy traffic. Vehicle immediately began to slow down and although there was some throttle response it was difficult to maneuver through traffic to get to the side of the road. This event happened around the 31,000 mile mark. The Reduced Engine Power message came on, but I do not remember hearing an audible alert. Being a 40 year Automotive Technician for GM, I am familiar with pulling codes and replacing parts. I called the dealership to see if this was covered by warranty and was told no. After pulling the codes, I personally replaced the Throttle Body Sensor and the Accelerator Pedal Assembly, but the vehicle continued to go into Reduced Engine Power mode. I took the vehicle into the dealership and they diagnosed the cause as a corroded connector. The connector was replaced and the vehicle was returned to me. After a little over one month and less than 1,000 miles the vehicle is once again going into Reduced Engine Power mode. I can have my vehicle available for inspection if necessary.

NHTSA ID

11431055

Incident

Jun 15, 2021

TRUCK SHIFT INTO GEAR VERY ROUGHLY. SHAKES WHEN DRIVING THROUGH ALL SPEEDS. FEELS AS IF SOMETHING IS FALLING OFF THE TRUCK.

NHTSA ID

11234127

Incident

Jul 23, 2019

Mileage

47,000 mi

WHEN DRIVING VEHICLE AT ANY SPEED IT STEERS TO THE LEFT OR RIGHT . NOT A SIMPLE ALIGNMENT PULL OR WANDER I CAN FEEL THE WHEEL AS TO WHICH WAY IT WANTS TO STEER AT RANDOM. IF NOT PAYING ATTENTION OR IF YOU WERE TO LET GO OF THE STEERING WHEEL IT WILL GO OFF THE ROAD ABSOLUTLY NOT SAFE TO DRIVE. WHILE ACCELERATING THE VEHICLE FEELS LIKE THE BRAKES ARE BEING APPLIED AND DOES NOT ACCELERATE I HAVE TO GIVE EXCESSIVE GAS PETAL THROTTLE TO GET UP TO SPEED. THERE HAVE BEEN TIMES I HAVE CAME HOME FROM AS SHORT DRIVE AND I CAN SMELL THE BRAKES THEY SMELL BURNT HOT. ONE INSTANCE I WAS MERGING ONTO THE HIGHWAY AND THE TRUCK STRUGGLED TO GET UP TO 60MPH I HAD THE PETAL FLOORED AND THE TRUCK WOULD NOT GO OVER 65MPH THE ENGINE WAS @ 5000RPM MAXED OUT IT WOULD NOT SHIFT NOR GO FASTER THAN 65MPH. RANDOMLY TRANSMISSION THUNKS THUD AND SLAMS INTO GEARS WHEN THE AUTOMATIC TRANSMISSION IS SHIFTING AT LOW SPEED BELOW 50. WHILE DRIVING TRUCK FEELS LIKE THE DRIVE TRAN IS BOUND UP LIKE BRAKE IS APPLIED ON INDIVIDUAL WHEEL(S) . I HAVE HAD NOTHING BUT PROBLEMS WITH THIS TRUCK VERY WEIRD ISSUES THAT DON'T MAKE MECHANICAL SENSE. ALSO THE INSTRUMENT CLUSTER GAUGES AND INFOTAINMENT SCREEN DON'T LIGHT UP JUST BLACK SCREENS AFTER STARTING VEHICLE. HAPPENED 2 TIMES NOW. RADIO WAS OFF WHILE DRIVING THEN CAME ON FULL VOLUME WITHOUT TOUCHING ANYTHING. SERVICE STABILITY /STEERING WARNING CAME ON ONCE.I CAN HEAR FRONT TRANSFER CASE ENGAGE AND DISENGAGE AT LOW SPEEDS RANDOMLY WHEN IN 2WD. RANDOMLY STUCK IN LOW GEAR WHEN ACCELERATING FROM A STOP. AND YOU DON'T HAVE TO USE THE BRAKES MUCH TO STOP YOU BECAUSE AS SOON AS YOU LET OFF GAS PETAL THE VEHICLE NEARLY COMES TO A STOP WITHOUT APPLYING BRAKES. AND IF YOU ARE TURNING IT WILL AT TIMES COME TO A COMPLETE STOP. HAS BEEN TO DEALER 6 TIMES NOW THEY SAY EVERYTHING CHECKS OUT. THERE IS A MAJOR COMPUTER ISSUE OR IS HACKED PER ALL IVE RESEARCHED.

NHTSA ID

11064915

Incident

Dec 7, 2017

Mileage

150 mi