general problems of the 2020 GMC Terrain - part 2

While driving I had to push the brake to the floor and a light came on saying reduced engine power. I pulled over right away and had my car towed to mechanic. The vacuum brake pump exposed and parts went into the engine. The mechanic got all the parts out but now engine has low compression and needs a new timing chain. This is over $3,000 so far. Gm recalled other vehicles with the exact same pump ? why not the Terrain.

While driving reduce engine power light came on and the brakes gave out. I weigh 250 lbs and took all my strength to get brakes to stop car. I tow it and mechanic showed me vacuum brake pump blew up and went into engine. He replaced that and timing chain but still needed work. Towed it to dealer and it needs a new engine $11 000. The dealer informed me they see this alot. ! why has gm recalled some on the vehicles that has this pump but not the Terrain. This is dangerous. If my daughter was driving she couldn't stop this car. It's now junk.

Incident happened August 9, 2020. Brakes suddenly stiffened and unable to stop vehicle. There were no warning signs or indicators. Thank goodness I was going at a lower speed and was able to coast into an area to stop. Ended up being the vacuum pump. This needs to be recalled ASAP. This could have been a fatal accident. I have kept the old vacuum pump as well as the pieces that were thrown from it that the mechanic had to dig out.

As I was driving, brakes became very hard to press. I was barely able to slow down to bring the car to a complete stop. Brakes became very stiff and required a ton of force to come to a complete stop. This came with no warning signs or alerts from vehicle. It was only after this occurred that the service break assist light came on.

The contact owns a 2020 GMC Terrain. The contact stated while driving 40 mph the "brake assist" warning light illuminated. The contact attempted to depress the brake pedal, but the pedal was stiff. The contact was unable to depress the pedal. The vehicle was taken to a local dealer and unknown repairs were performed. The vehicle was repaired; however, recently the failure reoccurred. The contact stated that the "brake assist" warning light illuminated, and the brake pedal was difficult to depress. The vehicle was not taken to a dealer or an independent mechanic to be diagnosed or repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 162,000.

This Saturday morning driving my family to bradenton as I was coming off the hwy to my exit when I experienced a brake fail I thought,brakes got real hard and I couldn't stop the car on time like I wanted too,so I had to press the brakes pedal harder to come to a complete stop,three different places no one new what could be the problem until I took it to GMC dealership they can only give a code p0556 / u0401 service brake assist, seems it was to late to checked out they where aboutto close , something to do with the busters not sure yet but it's getting checked out tomorrow morning, I was driving on cruise control at a speed limit when this happened,will let you know what's the result of my situation.

Brake booster failed with no warning. Brake pad was hard to push down as I exited the freeway. I came close to hitting the vehicle in front of me which would have resulted in a bad car accident. There were no warning. This is extremely dangerous and is a risk to not only the driver but also to vehicles in the path of a vehicle that cannot stop. This needs to be a recall along with the other vehicles that have a recall for this part.

Heard a ticking noise coming from the engine compartment. I opened the hood to investigate which I first check oil level as sounded like a lifter making the noise but all fluid levels was normal. I drove home and 3 miles later ticking noise went away and my adaptive brake assist came in and the brake pedal was hard to press. Luckily I lived another mile down the road so I got the car home and safely parked it. One of the symptoms is hearing a ticking noise from engine when a braking component fails. Further learned could be a vacuum issue which needs a software update which makes no sense. Had I been traveling highway speeds when this happened this story could have a had a very different tragic ending. Car has less then 53000 miles on it.

I was driving on the interstate when my brakes went out. I was able to get off at and exit and pull into a gas station but had to put on the emergency brake.

Driving down the freeway and all of a sudden got a service break assist notification and without warning I was unable to stop the vehicle. I was able to coast my way off the freeway and upon my exit I tried to pull into an empty parking lot but there was a fire fence I ended up crashing into which is probably what brought the vehicle to a complete stop. This is very dangerous and I have read numerous complaints from other 2020 Terrain owners who have experienced the same problem. Mechanic stated I need need vacuum pump for brake booster which of course my warranty doesn’t cover. Something seriously needs to be done about this. My accident could have been a lot worse.

While on highway service brake system warning light came on,brake became hard to apply almost causing an accident. Vehicle had to be towed to a repair shop(dealer). After paying over $1600 the problem was not resolved and found there are numerous complaints about issues with the Terrain and no recall issued. Are they waiting til someone dies before a recall?.

I was driving down the expressway. The traffic in front of me came to a stop. When I went to apply the brakes I had no breaks. The pedal was as hard as a rock so when I realized I couldn't stop I swerved over into the breakdown lane. And continue to pass cars at a high rate of speed until I got the car to stop. There were no check engine lights on then I had the car towed to the dealership where they tell me is a break vacuum pump. That has damaged the cam shaft. Pistons and rods in the engine. Totaling $7200. In damage. No one seems to care and I still owe 20000 on the car. Car has 71000 miles on it.

This GMC I just purchased in October 22 2022 and have been complaining since December 9,2022 the vehicle emergency braking will activate when I'm driving down the interstate or local roads I could be doing 70 and brakes will just lock up throwing me and my son forward , this has happened 4x , gas pedal when taking off at red light or pulling out the vehicle is hesitant and will not go this has happened on 3 different occasions. I called roadside on star they said there is a problem with the on star saftey feature will not work properly this was towed 2x to different shops, also while driving this vehicle it will just ingage itself in park while driving called on star they did diagnostic there was all kinds of coded for transmission and engine as well as emissions this vehicle is a safety hazard. . And I have tried to take back to dealership where I purchased they keep making excuses to not see this cpo with lifetime warranty and still under warranty from GMC vechle mileage was at 29k when problems stared vehicle only has 31k I can't drive this vehicle due to my son's and myself along with others saftey this is ridiculous and also GMC just informed me the VIN # they have for my vehicle and whats on it are two different numbers! yet nothing is being done I'm paying for a vehicle that I can't drive I have proof GMC knows about the fraud from dealership but GMC says its a sales thing this vehicle has been flooded two mechanics have confirmed and GMC is aware so why not do something I don't know exactly the history and GMC doesn't either please someone contact me GMC this is crazy and you know it's a safety issue with this 2020 GMC Terrain you even said so.

The brake system is only working at about 5%. There are known defects with other GMC models of this year and this vehicle should be reviewed .

My service brake assist light came on and then within seconds my vehicle then said engine power has been lowered and my vehicle pretty much shut down no steering no brakes couldn't do anything. Took it into the repair shop and my vacuum pump has shattered and now damaged my camshaft. I am aware there's been many other vehicles recalled with gm's vacuum pumps and I'm not sure why my year and model has not been included when it's doing the same thing and not to mention I have seen countless other cases of people saying same things happen to them with their GMC Terrains.

1- at 71,000 miles in 2022 brake vacuum pump “exploded” broke into many small pieces in the middle of driving. Causing brakes to lock. Brake pedal was brick hard. Hard to maneuver the car out of traffic without causing a collision. Luckily car was not being driven at high speed. At time of repair costing $1,000 mechanic informed me that the pump was made out of a non metal material and he could not fish the small particles out of the motor with a magnet. The motor would need to be taken apart, cleaned out and reassembled…. . From this point forward the car drives in “low engine power mode” even with repairs completed and codes cleared. 2- 2 years later the same part “brake vacuum pump” exploded again. Another $1000 repair. At this time we discovered that the fine particles that were not removed from motor has now knocked the timing off by 8%. Also it has caused a knick in a seal causing an oil leak under 100k miles $1800 repair. After these extensive repairs…… the car emits gas fumes into cabin. The smell is so strong it can’t be parked in the garage because it circulates through the house. Even when car is not running. The car can’t be driven because risk of fire or explosion from gas. Fuel system gets cleaned. Injectors replaced. The car temporarily runs without the gas smell. 2 weeks later the gas smell returns come to find out the fuel pump failed. Search online and find there is a recall for fuel pumps in this same make model and year. But not this VIN number. The car has been a headache from day 1. Recall the whole car at this point, to have so many faulty parts in such major systems of a car is crazy.

The emergency breaking system failed to engage. Failure to engage caused collision with another car.

Service brake assists light flashes on dashboard . Steering wheel locks up and jerk’s loose suddenly when making a right turn, in these moments when the steering wheel jerks loose ;hands are off taken off the steering wheel otherwise injury can occur. Battery life 2 -yrs old is not performing optimally. Can not hold a sufficient charge and esc light flashes. Vdnt valve leaks discovered.

The contact owns a 2020 GMC Terrain. The contact stated that while driving 50 mph, the vehicle lost braking power. The driver was able to pull over safely. There were no warning lights illuminated. The vehicle was towed to the local dealer, where it was diagnosed that the vacuum pump had shattered. The vehicle was repaired, but the failure recurred. The contact reached out to a GMC engineer, who informed the contact that the failure was due to the camshaft reluctor. While driving, the vehicle lost engine power. The vehicle was towed to the same local dealer, where it was diagnosed that the throttle body needed to be replaced. The vehicle was repaired, but the failure recurred. The vehicle was towed to the local dealer, where it was diagnosed that the turbo code had a mass air flow sensor failure. The vehicle was repaired. While driving at an undisclosed speed, the check engine warning light illuminated, and the reduced engine power message was displayed. There was blue smoke detected from the exhaust. The vehicle was towed to an independent mechanic, who informed the contact that the throttle had failed. The vehicle was towed to another local dealer, power GMC Chevrolet of newport (1422 n coast hwy, newport, or 97365) where it was diagnosed that the air pipe charge and air cooler needed to be replaced. The vehicle was repaired. The manufacturer was contacted and referred the contact to the local dealer. The failure mileage was approximately 50,000.

Unknown. . . Acts as if its a Smart car that's not really a Smart car.

Brakes hard to press. Almost cause an accident on interstate. Was able to contain vehicle. Took to autozone to assessed and it said powertrain system. Brake booster senor circuit.

The contact owns a 2020 GMC Terrain. The contact stated while driving at various speeds, the vehicle lost brake functionality while depressing the brake pedal. The contact stated no warning light was illuminated. The vehicle was towed to a local dealer where it was diagnosed with needing the vacuum pump replaced. The vehicle was repaired however, the failure persisted. The manufacturer was not informed of the failure. The failure mileage was approximately 40,000. The VIN was unavailable.

On fairly level ground, reduce speed hill descent control msg has activated (12 mile and maxwell area 2x, rochester hills kohls parking lot exit) and once entering river bend dr. Vehicle has also has had activated brakes on oak hill street in rochester. The vehicle has less than 4100 miles. Very concerning about activated brakes.

Service brake assist message came across screen after I was unable to push down brake pedal.

Every week it's something different. In motion. . . No cruze control. No audio. Don't drive over 50mph brake problem. Parking brake engages randomly and without user engagement. No awd. No stability traction. This happens so frequently the dash indicators have been reduced to �idiot lights�. At what point do I become concerned? things appear to resolve when the engine is turned off and back on, sometimes. . . . I compare it to other glitchy technology. However I potentially could be at an 80mph crazing speed when I decide to ignore the idiot lights. . . What happens when a real problem presents and I ignore the dash indicators do to frequent glitches? I'm so disappointed. My 2 previous Terrains were 10 times the vehicle the 2020 model year.