2019 GMC Terrain: check engine light

Filed Aug 21, 2026 · Brakes, Electrical · PA

On Saturday, August 15th we were driving on the freeway when with no warning the check engine light came on and the vehicle began to run poorly, and then the vehicle lost electrical power and it became difficult to steer and the brake pedal became stiff, making it difficult to stop and pull over. The vehicle would not start on command but kept running very poorly, it also became impossible to shut the vehicle off until it seized. It was later towed to a local repair shop, and today, Friday August 21st the shop confirmed that the vacuum pump on the brake assist failed and it would need a total engine replacement.

Filed Jul 3, 2026 · Transmission · IL

No engine lights are on. When at stops it starts chugging and when I accelerate sometimes it does not go like it should. It idles high and feels like it is slipping. I have almost been hit in the rear several times when this happens. One lady did rear end me but the damage was so little that I did not call the cops. This vehicle has not been inspected and it is available for inspection at any time.

Filed Apr 14, 2026 · AL

This is the 4th time my vacuum pump has “broke” my brakes become hard and stiff and my brake assist light comes on. It happens EVERY winter when it drops below freezing. This is the second time this winter it has broke and now my check engine light is on. It is not cheap to fix and a major safety issue. Would like to add I was only backing out of my drive way this last time it happened. I was going maybe 5-10 mph.

Filed Mar 28, 2026 · Brakes · VA

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.

Filed Jan 13, 2026 · Brakes, Engine · IN

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.

Filed Nov 11, 2025 · Electrical, Engine · MA

Vehicle has had check engine light and engine reduced power flicking on and off for months, randomly reducing power on highway or nearly causing accidents. Brought car to GMC dealer, they said it was underboost code and needed new turbo. Paid over 7,000$ for repair. Next morning, same issue still was happening. I believe my vehicle has EMISSIONS recall issue “N192271200 Charge Air Cooler Disconnect at Throttle Body” but GM has not properly attached my vin number for this recall repair. I have poured thousands into repairs out of pocket and the same issue still persists. I believe strongly the recall emission issue is the problem and should be on my vin. Vehicle has been to dealer 3 times in the past 2 weeks, issue has not been fixed. Improperly diagnosed, random repairs made not fixing actual issue.

Filed Oct 16, 2025 · Engine · 117,951 miles · NC

The contact owns a 2019 GMC Terrain. The contact stated that while driving at an undisclosed speed, the vehicle hesitated, with the check engine warning light illuminated. The contact stated that the warning light turned off after approximately three miles of driving. The contact also stated that the vehicle experienced abnormal RPM fluctuations while driving. The vehicle was taken to an independent mechanic, where it was diagnosed; however, the diagnostic information was not provided to the contact. The vehicle was not repaired. The vehicle was then taken to the dealer but was not diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 117,951.

Filed Sep 10, 2025 · Brakes, Engine · NY

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.

Filed Sep 7, 2025 · Brakes, Engine · MA

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.

Filed Jun 9, 2025 · Brakes · 80,000 miles · PA

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 federal safety agency Hotline to report the failure. The vehicle was not diagnosed or repaired. The failure mileage was approximately 80,000.

Filed Feb 4, 2025 · Brakes, Electrical · IL

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.

Filed Oct 24, 2024 · Brakes, Engine · MI

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