general problems of the 2019 GMC Terrain - part 1

Brake assist light came on and brake pedal became stiff/hard to push. Vehicle struggled to brake. Replaced brake pads and checked brake fluid. Brakes still inoperable. Check engine light came on for vacuum pump. When replacing pump, metal shards and pieces were falling out when original was removed. Once replacement was installed vehicle began hesitating to start and run.

Vacuum pump exploded into camshaft and engine area, causing me to lose brakes completely on the highway. Costly repairs to clear out metal shrapnel and replace camshaft.

I am driving a 2019 GMC Terrain slt, and I have a serious concern regarding a recent service experience. On 02/10/2026, I had an oil change and a complete vehicle inspection performed at kunes GMC greenfield, wisconsin. After the service was completed and I returned home, I noticed an unusual noise coming from under the engine hood. I immediately went back to the dealership and informed them of the issue. I was asked to return the following day (02/11) for further inspection. After their investigation, I was informed that the vacuum booster had failed. It appears that this issue was not identified during the original inspection, and I was the one who brought the noise to their attention. From my understanding, vacuum pump/booster issues are common with many 2019 GMC Terrain models. I am surprised that this has not resulted in a recall, especially considering the potential safety risks it poses to me and my family. What concerns me even more is that this issue was not detected during the dealership’s inspection. If it had worsened, it could have led to a serious safety situation. I had to spend $450 today to repair what appears to be a manufacturing-related defect. I respectfully request that this matter be escalated and that my claim for reimbursement be reviewed. I would appreciate your assistance in helping me pursue compensation for this expense.

Vehicle was started for the second time that day on 1/5/26 and the engine light was on. I drove the vehicle to an auto parts store to have them check it with an obd-ii scanner. It had code p050f. I had no idea how serious this issue could be at the time. I made an appt with the GMC dealership and dropped it off the evening of 1/6/26. They said there was a software anomaly in the engine control module and needed to be reprogrammed. I paid the $200 diagnostic fee for them to reprogram it. I learned that this anomaly could have caused my brakes to not work while driving it. I had been driving the vehicle back and forth to work until I dropped it off. This issue could have caused serious harm or death to myself and others. While researching online, I've seen that other vehicles have had safety recalls and additional warranties added for these issues, but my vehicle isn't included in this.

Failure of the cam driven vacuum pump causing brake failure. Leading to a hard brake pedal which increases risk of a crash. Debris from the broken vacuum pump can fall down into the engine causing a catastrophic failure of the engine needing a replacement. This happens with little to no warning. Warranty companies will not pay to repair the known issue. A recall needs to be issued for this to provide a fix. This is a family SUV and I do not feel safe putting my children in a vehicle that can endanger their lives and safety.

My cars breaks failed by a vacuum pump failer and I almost died on the a hill going home.

When approaching a stop sign, the brake pedal became extremely hard I was unable to stop, and rolled through the intersection avoiding collision. I was able to slow down enough to engage the emergency brake. There are no lights on the dash.

Driving approximately 70mph on interstate. Came to a slight hill, gently applied brake pressure, brakes become hard to apply/would not apply. After diagnostics, found brake vacuum pump with damaged fins.

I was backing out of the driveway, and it was extremely hard to brake enough to stop the car. I immediately parked back into the driveway. I had to stand on the brake to completely stop. Vacuum pump was completely busted and in many pieces.

Two weeks ago I was driving on the highway. My car felt fine. No warning light the dashboard. Suddenly I receive a notification on my dash stating “engine speed reduced” and my check engine light went on. My car at this point still feels fine, not shaking, no smoke, etc. I’m on the highway and not in a safe position to pull over. 2 minutes later I receive another notification on my dash stating “service breaks”. I immediately tap my brakes to check and they are stiff. I let off the gas as I was approaching the exit and begin pumping my brakes. They continue to be stiff. Luckily there was no one I front of me as this exit led to a rotary. I was able to coast around the rotary and into a parking lot where I attempted to push the e- break which did not work. My steering tightened and then my car died. I have the car towed to GMC where I bought the vehicle. Am told I will be charged a diagnostic fee and they will let me know what they find before repairs are made. I receive a call back the following day stating “the vacuum pump exploded causing you to loose brakes”. I was told “the vacuum pump and repairs would be about $1,200. But they could not guarantee that once the vacuum pump was removed, there wouldn’t be more debris and destruction to the cam shaft and engine”. We asked they continue with the diagnostics and check the engine for debris. We receive a call back stating “the vacuum pump exploded and there are shards of medal debris in your engine”. Recommendations are that I need a new engine as "the vacuum pump explosion caused catastrophic damage to the engine". My safety and the safety of other innocent drivers on the highway were put in extreme danger! I lost all break control, power steering, and emergency break control. I had minutes from the time the first warning alerted to the time I lost complete control of the car. This is a known issue with gm motors specifically made between 2016-2019.

While driving the vehicle the car went into limp mode and the back brakes stopped working. The car had to be drifted into a parking lot. The vacuum pump malfunctioned and has damaged the engine. If it was me in the driver seat instead of my partner, the incident would’ve 100% been an accident. The car was really unable to be controlled and we just happened to have that space that was empty to turn into. The car gave code when this happened. When getting a tow the car also wouldn’t take itself out of park or start to go into neutral to move the car to get it towed. Nothing is working with each other anymore and we were on a busy road of people when our brakes just went out.

Friday July 25, 2025 I was driving my 2019 GMC Terrain sle and when exiting the interstate the brake pedal got hard and I could not stop. After almost rear ending another vehicle, I got the vehicle into the ditch and safely off the road. After several attempts to correct the problem, I was unsuccessful. The vehicle was towed home and seen by a mechanic. The vacuum pump went out while I was driving.

While working out of town for work my engine light started flashing and the dash lights went nuts. My brakes were nonexistent and were hard as a rock. I had zero warning as to what happened. Working 3 hours away from home the car had to be towed and I was informed the engine code came back as my cam shaft. Took it to the dealer as gm has a bulletin put out. I didn’t know what that meant. Long story short and 3000. 00 dollars later I find out that the vacuum pump exploded which cause the cam shaft to fail. I was out of work for almost a month. There is a recall for almost all vehicles from this year but not the 2019 Terrain even though it contains the same vacuum pump as all the recalled makes and models. Vacuum pump, cam shaft, oil pan, oil pump had to all be replaced at under 100,000 highway miles. Someone needs to address this problem.

The contact's wife owns a 2019 GMC Terrain. The contact stated while driving 70 mph and depressing the brake pedal, the brake pedal was firm, and the vehicle failed to respond as needed. The check engine warning light was illuminated. The contact stated that upon depressing the brake pedal with excessive force, the vehicle responded as needed. The contact stated upon inspecting underneath the brake booster, the contact noticed a lot of debris due to lack of vacuum pressure. The dealer and the manufacturer were notified of the failure and referred the contact to the NHTSA hotline to report the failure. The vehicle was not diagnosed or repaired. The failure mileage was approximately 80,000.

Vacuum pump broke and car has no brakes.

While driving the breaks completely locked up and the smell of exhaust entered through vents. Ran a code machine indicating that the break booster power vacuum pump was needing replaced. There are no other issues with my vehicle that would cause it to malfunction out of no where.

Breaks went out on vehicle with no warning or lights on dash. Nothing prior or now indicating any issues with breaking system.

Brake vacuum pump premature failure. As you see GMC, Terrains, in equinox, I have an issue, while the engine it's on while driving etc, if this bark fails, you will have an issue I'm trying to stop. This is a known problem or gm. And as of now, they have not come out with a solution or a recall for this problem. This problem has caused many customers. To lose thousands of dollars, he repairs. I'm not covered by the warranty. This should be addressed and repaired as soon as possible as it may cause someone else to lose their life. Second problem is the 9 speed transmission transmission lack power when trying to gain speed as you enter the highway. Lastly they blamed the selenoids etc. Lastly the pulley belt retention broke down premature with only 68k miles. This is an ongoing problem gm is well aware and tries to hide or fix. When someone buys a vehicle we expect to last longer than 100k miles.

Vacuum pump failed causing hard brake pedal and the inability to properly stop the vehicle. Thankfully I made it to a safe area and had the vehicle towed. No warning light or engine service lights ever illuminated. Once it was taken apart the bearings were disintegrated and metal shavings are in engine components.

Service parking brake comes on, steering reduced. Problem reoccurring often, but intermittently. Actuators malfunctioning causing many sensors to fail off and on. Huge safety concern for myself, my riders, and anyone else on the road. When this happens my car has to “think” to move unless you clear the pop up message. Check engine light comes off and on at its leisure. When steering reduced comes on the car will not move until ready. This is clearly affecting electrical things as when I shut power off to other supplies it sometimes becomes more frequent as well as less frequent. The car does not understand what to do as its computers are confused at what the problem is, as the problem does not consistently happen. I have print outs of one time I caught it with failing actuators. I refuse to go to the dealership as I’m told “OH the problem isn’t happening now. ” which negates safety of all people on the roadways. You’re more than welcome to inspect. Though I will be present as I refuse to be told there’s no problem. As previously stated this happens when it wants to happen, but again I’ve caught the issue and can supply information.

Driving home from dropping my daughter off at school. When slowing down at stop sign, car locked up brakes completely, almost went through stop sign, car shut down engine and placed vehicle in park. Diagnosis is a vacuum pump failure, causing reluctor wheel to spin freely from camshaft. This happened without warning at 70k miles. Diagnostic report from three weeks prior showed no bad diagnostics with engine or drivetrain components, or brake components. Had to have car towed from intersection where I was impeding traffic due to sudden failure. Garage is concerned regarding potential for debris and engine damage, as well as timing issues due to sudden failure of vacuum pump. Gm has authorized vacuum pump recalls on other makes from prior years, not Terrain for some reason. This is how becoming highly reported failure among GMC/chevy vehicles with shaft driven vacuum pump design between 2019-2022. Gm has stopped using this design on 23 and newer models. They should absolutely recall these older models for this issue. Sudden vacuum pump failure can lead to unrepairable engine damage due to design.

We have been having varying issues with this GMC, and have found numerous others with the same issue. Vacuum pump went out while driving. Thankfully I was not going very fast and it stopped prior to hitting someone. This is a known issue, yet no recall from GMC. Vacuum pump is said to have been failing causing other engine and transmission issues that can never be "re-created" for the vehicle to be fixed.

At 86,000 miles information board on dashboard alerted “service, brake assist” upon braking from coming off of interstate. Diagnosed to a failed cam shaft driven vacuum pump for power brake booster, next to no braking power with little to no warning what so ever. Terrible design from gm. Near miss collision due to brake failure with no warning. This needs an immediate attention through the engineering department to create a redundancy within the system. Nearly caused a very bad accident with my [xxx] and [xxx] daughters in the vehicle while fiancé was coming to pick me up from being on the road as a otr truck driver. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

The brake vacuum pump failed. I am extremely fortunate this happened at a rest stop after being on interstate 80 for numerous miles. Had this happened at highway speeds it would have been catastrophic for myself and most likely others. I do not have the part. The problem was confirmed and the psrt was replaced by mavis discount tire in mountain top, PA there were no warning lights, signs, or symptoms prior to the malfunction. It is my understanding that gm has recalled the part on other models, but did not include the Terrain in the recall. I believe it should be before someone is seriously injured.

I was riding on the freeway when my brakes failed. I was not able to press down on my brakes with zero warning. I had to swerve to miss cars and pull on the shoulder of the freeway and my car still would not slow down. I finally got from 65 to 35 and pressed on my emergency brakes. I stopped the vehicle then my engine light came on and I got my car towed to the car shop where my car would not stop and suffered internal damage to my engine from the brakes and vacuum pump.

My esc randomly comes on. Service parking brake message comes on intermittently. Messages pop a up saying steering wheel assist limited, drive with care. Again, all of these are intermittent but when they happen my steering wheel locks up. Even mid turn. Being intermittent it doesn’t always happen and weather seems to affect when it happens, or that’s a coincidence.

The brakes failed with zero warning while driving. Car only has 60,000 miles. Extremely dangerous and it looks like it has been reported and known issue! it needs to be recalled.

On two occasions the vacuum pump booster failed causing the vehicle to lose braking ability while traveling on a highway at highway speeds. The vehicles brake completely failed and were unable to be engaged. The part was initially replaced by the dealer at the owner's expense and then the same issue occurred only a few months later. The second occurrence cause additional damage to the camshaft and timing chain causing the vehicle to not even be able to start. The vehicle was inspected by the servicing dealer and found metal shavings in the oil as well as extensive damage to the engine.

My family and I were returning home from vacation in another state, and while we were driving on the interstate, an alarm popped up on the dtc stating ruduced engine power. I tried to start slowing down so I could take the next off ramp and could not push the brake pedal in. I had absolutely no brakes trying to slow down from interstate speed. I was able to pull into a gas station parking lot while avoiding other vehicles. I was very lucky not to get in an accident. I had to have it towed to the nearest service center and was charged nearly $4000 for repair. The car has not ran right since we recieved it back. I called them back to let them know and was told the only way I would not have to pay to have it looked at was to bring it back to them. That shop was four and a half hours away from my house. The car was less than twenty miles out of the warranty when it broke down (nine miles to be exact), then they lied on the the paperwork and put the milage after they test drove it.

My daughter was driving her 2019 GMC Terrain at 15 - 20mph when she suddenly lost her brakes. Fortunately she had just turned into a new housing development where the road ended into an empty field. This could have been catastrophic for her & other citizens on the road. The following morning she would have been heading to work on a highway with heavy traffic with a posted speed limit of 65mph. We towed the vehicle home & after some investigating I found a vacuum pump failure. This vacuum pump broke apart internally sending chunks & shards of metal into her valve train. This issue is mentioned several times in Terrain forums & someone needs to address this issue before it becomes a fatality.

The contact owns a 2019 GMC Terrain. The contact stated that while the wife was driving approximately 60 mph the braking system failed causing the brake pedal to become hard while pressed and the vehicle would not immediately stop. During the incident a second vehicle crashed into the front driver's side of the vehicle. During the crash the vehicle was destroyed. The driver, front passenger and rear driver's side passenger all sustained headaches as a result of the crash which did not require medical treatment. No occupants in the second vehicle were reported injured. A police report was taken at the scene and the vehicle was towed away. The contact indicated that during the incident the abs warning light had activated. The cause of the failure was not determined. The manufacturer and local dealer were not contacted. The failure mileage was 40,000.

Break booster pressure sensor and engine underbooster causes the car to slam on breaks or not break at all.

The contact owns a 2019 GMC Terrain. The contact stated that while driving at 30 mph, the brake pedal was depressed, but the vehicle failed to stop immediately. The contact slammed on the brake pedal, and the vehicle came to a stop. The contact coasted the vehicle to the median. The vehicle was restarted and driven to the residence. Upon inspection, the contact noticed that the brake fluid was dark in color. The vehicle was taken to an independent mechanic, who diagnosed that the vacuum pump had failed and exploded in the camshaft. The vehicle was then towed to the dealer, where it was determined that the vacuum pump, camshaft, valve cover gasket, and water pump needed to be replaced, along with an oil change. The manufacturer was made aware of the failure and a case was opened. The failure mileage was approximately 120,000.

I had just gotten off the highway and had gone less than a mile on a 35 mph road when the brakes acted like the antilock brakes came on for a brief second then the brake pedal became very hard to push. This resulted in me having a difficult time stopping the vehicle. The service brake light also came on.

Vaccumm pump failed and broke metal shavings off into engine resulting in “engine failure”. I was driving on the highway with my 6 year old child in back seat, car completely shut down and shot a “reduced engine power” message while on a busy on ramp heading onto highway. This created an extremely dangerous situation for myself and my child as many cars almost smashed into the vehicle. I’ve seen many other complaints of this happening, the same exact parts and issue happened to the chevy equinox which resulted in a recall but they have yet to recall the Terrain, which is having the exact same issue. I am a single mother, with 20k still on my loan. This mistake made by GMC has now costed me over 5,000$ out of pocket for something that is not my fault and completely out of my control. Even after all of the money poured into this repair, I still feel unsafe in my own vehicle as there is no guarantee this issue will not happen again. I’ve kept up on all oil changes and maintenance of my vehicle. The issue was confirmed by a GMC mechanic which cost 500$ out of pocket for diagnosis as well. I also had to spend 1000$ on a rental out of pocket because of this. I have seen many others complaints of the same issue happening to their GMC Terrain and am appalled no recall has been discussed after the reaccuring issue. I should not be having to pay out of pocket for an issue GMC has yet to fix or issue a recall on. I had to miss days of work, and it really was a huge inconvenience. I do not feel safe in my own vehicle even after the repair, cause I have no guarantee this won’t just happen all over again.