2012 GMC Terrain electrical problems

Filed Nov 16, 2025 · Electrical, Engine · MO

1. The engine suddenly lost power while driving during evening rush hour and the vehicle would no longer accelerate. 2. Because the vehicle could not maintain speed, I was unable to keep up with traffic, creating a serious safety hazard that could have resulted in a major accident. 3. The vehicle has been inspected by an independent service center for diagnosis. 4. During the incident, the “Engine Power Reduced” warning indicator illuminated just before the loss of power occurred. 5. As the vehicle slowed and came to a complete stop at an intersection, it remained unresponsive. When the traffic light turned green, the vehicle would not accelerate at all.

Filed Apr 14, 2023 · Electrical · MI

The display screen of GPS/Radio is blackout combined intermittent control button illuminating light went off( include emergency, A/C control), backup camera stopped working, turning signal lost click sound. Safety concern: 1. Emergency and A/C control buttons lost illuminating light(Causing night driving difficult.). 2. AC vent the temperature control lost visual status cause distraction of normal driving. 3. Lost Backup camera function which is supposed to be an assisted safety feature. 4. Lost turning signal click sound which leads to missing alert of turning signal malfunction. 5. Complete audio loss create unsafe for long trip driving. 6. GM doesn't provide genuine replacement part. This problem started from 2018 till now. I've contacted GM with no meaningful resolution. I visited the dealer and the only thing they could do is replace non guaranteed refurbished head unit with hefty price. I did some research online and found there are a lot of same problems happened to this vehicle and similar models of GM. After driving this vehicle for several years without incurring any accident, I realized that the losses of the some vital control functions and safety alert are actually very serious concerns and should be addressed and resolved by GM.

Filed Apr 11, 2023 · Electrical, Engine · MI

When I stop at the light my car shake and rocks, then the car goes into limp mode. Where the stabilitrack comes on and the engine goes into reduced mode. And I can't go over 30mps. When this happened on the freeway is the most dangerous and scary feeling ever. I've got So many new parts and put over 3,000 into the car and it still has this issue. I've been do several different mechanics and nobody can figure out what's wrong. Gm needs to look into this, it's so many forums going on for this issue.

Filed Jun 20, 2022 · Brakes, Electrical · KY

The check emissions light for the engine light came up on the dashboard. Without prior warning or other signs the vehicle lost engine power in the middle of the road. The entire electrical power and engine stopped working and the brakes jammed. This causes the vehicle to become unstoppable in the middle of the road causing a safety hazard to the vehicle, driver, passengers and fellow vehicles on the road. The only way to stop the vehicle is somehow use the gears to shift to parking position, turn the engine again on and try to remove the vehicle from the middle of the road.

Filed May 10, 2022 · Electrical, Lights · 78,000 miles · PA

The contact owns a 2012 GMC Terrain. The contact stated that the vehicle failed to start. AAA arrived at the contact's residence and replaced the battery. The vehicle was then taken to an independent mechanic where the plugs and other unknown parts were replaced however, the failure recurred. The contact replaced the battery twice. The contact also stated that the passenger's side headlamp had failed. The contact later received notification of the federal safety agency Campaign Number: 22V137000 (Exterior Lighting) which he associated to the failure. The dealer was not contacted. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was not notified of the failure. The vehicle was not repaired. The failure mileage was approximately 78,000. VIN tool confirms parts not available.

Filed Jul 6, 2021 · Driver assistance, Electrical · AR

Over the past couple years I have become worried to even drive this vehicle. Well Taken care of and maintenance completed regularly. This vehicle has been in the shop 7 times in the past couple years but no one can tell me exactly what is going on. Only 1 place has told me that I need extensive electrical work but couldn't tell me what exactly the problem was. Issue #1: When coming to a stop, and/or idle, the engine seems to give up and vehicle shuts off. Issue #2: When started Engine sounds like a.high pitch raddle. Issue #3: Occasionally, while driving on the interstate going around 60 - 65 mph the electrical inside the vehicle will flash and everything shuts off and the emergency brake is applied automatically. This has become dangerous - if I wasn't wearing a seatbelt I could have been thrown through the windshield. Issue #4: Replace Fuel Cap Sensor comes on even though it's been replaced. Issue #5: Engine Power Reduced notification comes on even though it had a new battery and alternator. Issue #6: Occasionally Speakers sound blown and you can hear a buzzing as you accelerate. Issue #7: Stabili Track, ABS, and TPMS Sensors all come on at once and go away at once atleast 4 times a week. Issue #7: Rear Cam doesn't always work, sometime either black or static looking. Issue #8: Sometimes key sticks in ignitiin and will not turn on unless being jumped by another vehicle. Issue #9: Often upon starting the whole dash goes black and will stay that way for several hours then comes back on. I've checked all fuses and multiple mechanics can't figure it out. As time goes by without repair I'm scared to even drive this vehicle. Why can't someone figure this out!!

Filed May 27, 2021 · Electrical, Engine · TN

My vehicle has excessive oil consumption including the need for frequent oil refilling, combined with audible rattle and knocking sound.

Filed Apr 2, 2021 · Electrical, Engine · 120,000 miles · MO

During a bad storm the windshield wipers went past the windshield and the motor froze up motor started humming then locked up.

Filed Jan 17, 2021 · Electrical, Engine · IN

Stationary sensor lights come on steering monitoring warning also reduced engine power then doesn't come on after turning off and it doesn't turn off like it should it is like the engine begins choking.

Filed Oct 2, 2020 · Electrical · 123,445 miles · WV

The defroster will not switch air flow to vent. This causes the entire car to fog up constantly especially the windshield during rain or humid weather. This obstructs view and creates a life threatening hazard. This happens while driving constantly on highway I side street.