2015 GMC Sierra 1500 Problems

What owners report

Owners of this model year most often write about brakes that lose assist at low speed — the pedal dropping to the floor or going stiff while parking, backing up or creeping in traffic — sometimes after the vacuum-pump recall work was already done. Transmission complaints are the second theme, usually harsh shifts, shuddering or slipping at moderate mileage. Steering assist dropouts, exterior lighting problems and a range of smaller electrical issues also appear repeatedly.

1. 1
   Brakes

   Brake pedal goes to floor or goes stiff at low speed

   • 188 complaints (26%)
   • median 55,000 mi at 4.2 yrs old (145 state mileage)
   • 14 mention a crash, fire or injury
   • owner-quoted repair $1,014 (median of 10 quotes)
   • filed 2017–2026

   Complaints describe the brake pedal sinking to the floor or becoming very hard to press while parking, backing out of a driveway, creeping in stop-and-go traffic or pulling a trailer, with the truck continuing to roll until the pedal is pumped or the engine is revved. Several owners say the vacuum-pump recall remedy was performed and the symptom returned or was unchanged, and some say the dealer told them their VIN was not covered. Others report the brake booster pump or vacuum assist being diagnosed, and a few describe a shudder or noise through the pedal when it happens. Reported across a wide mileage range, from roughly 50,000 to 150,000 miles, mostly at low speeds in parking lots, driveways and traffic.

   Recall 19V645000Recall 19V761000

   What to check: Ask whether the vacuum-pump recall (19V645000) was completed and keep the paperwork; on a test drive, try slow parking-lot stops and reversing and note whether the pedal stays firm and high.

   2 excerpts from owner complaints in NHTSA records

   “In slow traffic today I almost slammed into the back of a car! The brake pedal went to the floor,and had a shutter feelin terrible!! This is scary and needs recalled now!! I heard it was but came up no with my VIN#?? But my year is supposed to be recalled...this needs fixed im not happy after today..”

   NHTSA complaint #11365657, filed 2020-10, 91,000 miles

   “The brakes failed as my son approached an intersection. Subsequently, he struck another vehicle broadside. Extensive damage was sustained to both vehicles. The driver reported that he pressed the brake pedal, but the truck would not stop. After I investigated further for an explanantion,I discovered that there was a recall on his brake system that might explain brake failure. The crash occurred on a city street.”

   NHTSA complaint #11354432, filed 2020-09, 150,000 miles
2. 2
   Transmission and drivetrain

   Harsh shifts, shudder and slipping (8-speed automatic)

   • 63 complaints (9%)
   • median 40,000 mi at 4.3 yrs old (33 state mileage)
   • owner-quoted repair $5,200 (median of 6 quotes)
   • filed 2015–2026

   Owners describe hard or jerky shifts between the low gears, a shudder or vibration at cruising speed in third and fourth gear, delayed engagement when shifting into drive, and occasional slipping with no warning light. Many say the dealer reprogrammed the transmission or flushed the fluid, sometimes charging a diagnostic fee, and that the condition came back; a number were eventually told the transmission or torque converter needed replacement. Several complaints say they were told the behavior was normal. Mostly reported between about 25,000 and 100,000 miles; a few owners note the shifts are worse in cold weather.

   4 related service bulletins

   What to check: Drive it cold and warm and feel for clunks or shudder on light-throttle 1-2-3 shifts and at steady 30-40 mph; ask whether any transmission reprogramming or fluid service has already been done.

   2 excerpts from owner complaints in NHTSA records

   “Torque converter. Me and along with 4 other people are having problems with it. Upon start up and driving it starts to get sluggish and then just comes almost to a complete stop only building RPM's accrodding to the GM dealership it's normal. With all the Gmc trucks I've owned it has never done this. And is only starting to do it over the past couple of months. I've talked to a guy who just had 2 replaced in his truck and is continuing to have the problem. …”

   NHTSA complaint #11299110, filed 2020-01, 77,000 miles

   “My 2015 Gmc sierra has the 8 speed transmission which has been an issue since I have owned the vehicle. I bought the vehicle used in the fall of 2018 and the truck/tranny ran good for about 10 months. Then in late summer and early fall of 2019, the truck jerking hard shifts started to appear. In october of 2019 I brought my truck into my dealer to have them look at my tranny due to the really hard shifts from 1st to 2nd or 2nd to 3rd and vice versa 3rd to 2nd and 2nd to 1st. …”

   NHTSA complaint #11329309, filed 2020-06, 71,122 miles
3. 3
   Steering

   Power steering assist cuts out briefly

   • 71 complaints (10%)
   • median 55,000 mi at 4.3 yrs old (46 state mileage)
   • 4 mention a crash, fire or injury
   • filed 2016–2026

   Complaints describe the steering wheel suddenly becoming very hard to turn, usually at low speed while turning or parking, sometimes with a service power steering or StabiliTrak message and then normal assist returning after a few seconds. Some owners link it to the electric power steering recall and say the problem recurred after the recall repair; others were told the VIN was not covered or that a battery cable was the cause, and repairs did not resolve it. Usually reported between about 15,000 and 110,000 miles, often during turns at low speed.

   Recall 18V586000

   What to check: Confirm whether recall 18V586000 was performed and check for stored steering or StabiliTrak codes; during the test drive, turn at low speed in a lot and watch for a warning message or a momentary heavy wheel.

   2 excerpts from owner complaints in NHTSA records

   “Pickup has had reoccurring service power steering message come up in information center. Took to GM and they said it needed a new negative battery cable. Bought one and installed it. Still have the same problem. Upon dong some searching, its a very common problem among certain GM vehicles. One weekend the power steering quit working all together at 70 MPH on a curve. Talk about scary! I called GM customer service to ask about coverage on the issue and was denied because my vehicle was not one affected by the suspect faulty parts. …”

   NHTSA complaint #11323242, filed 2020-05, 73,000 miles

   “When at highway speeds of approximately 65+ MPH the vehicle begins to vibrate or shake violently as if the rear end of the truck is about to fall out. It is bad enough to make you white knuckle the steering wheel cause you to swerve slightly”

   NHTSA complaint #11301004, filed 2020-01, 70,000 miles
4. 4
   Exterior lighting

   Headlights dim, fail or collect moisture

   • 90 complaints (13%)
   • median 1,152 mi at 1.4 yrs old (64 state mileage)
   • filed 2015–2025

   Owners report headlights that are noticeably dim at night, both beams cutting out at once, moisture building up inside a headlight housing, and one side appearing dimmer than the other. Some also describe a fast-flashing turn signal with a bulb-out message even though the bulb still works. Complaints mention bulb replacement, sometimes under a service bulletin, without lasting improvement, and a body control module recalibration being needed. Reported at very low mileage in some cases and up to about 110,000 miles in others; many describe nighttime driving.

   3 related service bulletins

   What to check: Check both headlight housings for fogging or moisture and compare brightness side to side at night; ask whether any body control module calibration or bulb-out detection work was done.

   2 excerpts from owner complaints in NHTSA records

   “While driving home the other night both headlights failed at the same time. Lost both high beam and low beam. Tried everything to get them on with no luck. Interment panel showed that they were still on. This was very scary and dangerous as I has traveling on a major highway. Luckily I had fog light to give me some light to gt off the highway safely.”

   NHTSA complaint #11374270, filed 2020-11, 5 miles

   “While the head lights and fog lights are on, the right head and fog lights are dim but the left head and fog lights are bright. Also the right turn signal shows error message on the cluster that the bulb needs to be replaced and you can hear it blinking fast, but when I exit the vehicle to inspect the signal I notice that it is not blown and it works fine but I still get the error message and the fast blinking. Both stated problems occur while the vehicle is stationary and when the vehicle is in motion.”

   NHTSA complaint #11327678, filed 2020-06, 112,843 miles
5. 5
   Air bags

   Seat belt cable separates at the anchor

   • 40 complaints (6%)
   • median 65,000 mi at 5.3 yrs old (17 state mileage)
   • 4 mention a crash, fire or injury
   • filed 2016–2026

   Complaints describe the lower section of the driver's seat belt, where the cable attaches near the floor, snapping or coming apart so the belt no longer restrains, and one owner reports the belt tensioner cable being the repeated failure point. Dealers in these reports said there was no recall or warranty coverage for the failure, or that parts for the roof-rail air bag recall were not yet available. Reported from about 25,000 miles to over 130,000 miles, typically noticed while buckling or entering the vehicle.

   Recall 16V209000Recall 16V651000Recall 17V437000Recall 21V245000Recall 20V736000Recall 21V504000

   What to check: Pull the driver's belt out fully and look at the cable and anchor by the seat base for fraying or separation, and check with a dealer that the seat belt pretensioner and roof-rail air bag recalls were completed.

   2 excerpts from owner complaints in NHTSA records

   “The contact owns a 2015 GMC Sierra 1500. The contact stated while driving at an undisclosed speed, the air bag warning light illuminated. The vehicle was taken to the dealer; however, the diagnostic test had not been completed. The contact stated that the vehicle had previously been repaired under NHTSA Campaign Number: 20V736000(Air Bags) in 2020. The manufacturer was made aware of the failure. The failure mileage was approximately 119,000.”

   NHTSA complaint #11592822, filed 2024-06, 119,000 miles

   “The contact owns a 2015 GMC Sierra 1500. The contact received notification of NHTSA campaign number: 21V504000 (Air Bags) however, the part to do the recall repair was not yet available. The vehicle was taken to the local dealer and it was confirmed that parts were not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. VIN tool confirms parts not available.”

   NHTSA complaint #11455828, filed 2022-03, 25,000 miles

Buying note. Check the recall history for the vacuum-assisted brakes, steering assist, seat belt pretensioner and roof-rail air bag campaigns, since several owners report symptoms returning even after repairs. A thorough test drive at low speed in a parking lot, plus a cold-start drive to feel the transmission shifts, will show most of what owners complain about.

Summary written with AI from a sample of 60 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.