2018 GMC Terrain Electrical System Problems

The infotainment system will just randomly start going haywire and when it happens, you cannot use the touchscreen. It will try to randomly delete app icons such as the camera, it will try to delete connected phones, it will try to delete radio favorites and it will move app icons all around. These are just a few examples of things that happen.

Component Affected: Service Brakes, Hydraulic – Brake Vacuum Pump Summary of the Problem: I am reporting a serious safety issue involving the brake vacuum pump on my 2018 GMC Terrain. The brake pump failed catastrophically ("blew up"), resulting in a sudden loss of braking power. This occurred without warning and posed a significant risk to my safety and others on the road. We were traveling to vacation in Florida and thankfully had just gotten off the interstate. Details: The failure caused the brake pedal to become extremely hard to press, and the vehicle required a much longer distance to stop. We experienced no brake at the brake booster and a blown vacuum pump is due to a faulty vacuum pump which is a known issue for this model. Fortunately, no accident occurred, but the situation could have easily led to a collision. A certified mechanic confirmed that the brake vacuum pump exploded and needs to be replaced. I have incurred significant out-of-pocket repair costs due to this issue. We had to uber to our vacation room, get Walmart Plus to have groceries delivered to our room. We had to have Uber Eats deliver other supplies. We have had to walk to various places for dinner and entertainment because Avis and Budget had no vehicles available to rent and Enterprise was closed as we arrived on Saturday afternoon. I have checked for recalls and service bulletins using my VIN, but none are currently listed for this specific issue, despite similar problems being reported in other GM vehicles. Request: I urge the NHTSA to investigate this issue further. The failure of a critical braking component without warning is a serious safety concern. I believe this may be part of a broader pattern of brake system failures in GM vehicles and should be addressed through a recall or safety campaign. Also, the estimate for the repair is $2,500 so any reimbursement would be greatly appreciated. We just received this estimate but I can provide it at a later date.

The contact owns a 2018 GMC Terrain. The contact stated that on several occasions while driving at various speeds, the infotainment system screen and radio inadvertently switched stations from AM to FM. On other occasions, while driving and using the GPS system, the screen went blank. The contact stated that on several occasions the screen was turned off, and on other occasions, the screen was turned off and on however, the failure was temporally fixed. The vehicle was not diagnosed of repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 77,000.

The contact owns a 2018 GMC Terrain. The contact stated while driving at an undisclosed speed, the contact became aware that the horn was inoperable. There was no warning light illuminated. The vehicle was taken to the dealer. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The failure mileage was not available.

Safety was put at risk when brakes went out without warning, and unable to use emergency brake at that time. Car was serviced for over $1700, with the mechanics stating that the piece “blew up.”

Rear side windows in hatch area leaked filled up spare tire compartment with about 3-4 gallons of water. Now navigation doesn't want to work, sunroof not working, electric systems are not working right

The door locks began to have issues; the locks started to work only occassionally for no apparent reason. I've been locked out of the car several times and had to use the auxiliary key. Plus I couldn't lock the car while I was inside as the interior door lock button wouldn't lock or unlock the doors either. It's not a kefob or battery issue and no lights on the dashboard. The dealer reports that they couldn't reproduce the issue. However they found corrision on the electrical harness inside the passenger front door. I replaced an electrical harness in the rear bumper 18 months prior for corrision found. The dealer says they received a service bulletin on the "electrical harness" issue however the dealer won't cover the cost of $500 to replace the harness. As this deals with the electrical system, my concern is that it may effect the operation of other components of the car while it's running. Safety and security is of the utmost importance whether at home or away as it regards to being able to lock or unlock the doors.

On Wed., Dec. 6 around 3:15 pm during heavy traffic on FWY [XXX], cars slowed down to a brief complete stop. When I went to start slowly as traffic began to move, engine completely shut down. I could not open windows or my door to get out of vehicle. Immediately called 911 and was transferred to DPS. It took approximately 65 minutes before I had help and was finally towed from the dangerous freeway lane where I was stuck and with vehicle completely stalled and locked down, I couldn't even get car in N to be able to have help moving to a non dangerous place outside of the FWY lanes. This is the fifth time this car locks down. I've learned to open a panel by the foot brake area, pull a lever in that area and be able to move the car to a safe location until I got towed into the dealer. It is the second time that this has happened in a potentially dangerous street and now Freeway. Danger to myself and many others that had to maneuver around me. The first time (around 2020) the car totally shut down, it was reported that a computer harness had to be replaced. This last time I was faced with such a dangerous situation on a FWY it was determined that the ECM (Engine Control Module) had caused the shutdown and locked the vehicle to where I could not even get out for close to an hour. The ECM was replaced by GM and the car is running again, but my shock and trauma still haunt me as to the self and others danger that was present. . GMC Dealer finally determined after several attempts that ECM was the problem. Unsure if available to inspect it. Delivered car back 12/8. . Heavy freeway traffic at peak hour put me and many others in serious danger. . My dealer report reads it was difficult to diagnose and finally find ECM was the problem. .Vehicle has not been inspected by Manufacturer, police, or insurance. .A few minutes before this lock-down an engine icon appeared while on the FWY. Previous shutdown incidents had no warnings or messages before locking up. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Temperature sensor for the engine went out...which now affects my remote start not to work

Radio, hands free calling, and light on mirror shorting out. None of them work. It’s like it has a short in the wiring.

Unknown

1. 2018 Terrain would not start in a parking lot. Remote was used after several attempts to start with push button failed, and after a slight hesitation , engine started. Vehicle was driven about 6 miles without incident. 2. Vehicle was driven about 10 miles the next day and start/stop engaged at a stop light but would not restart. After about 3 minutes of cycling throught the starting procedure, the vehicle started. Drove another 8 miles without incident. 3. Next morning, drove about 3 miles to intersection where start/stop engaged but would not restart. After about 30 minutes of cycling through starting procedure and an attempt to jump start was made the vehicle restarted. At this point, the vehicle was taken to Romain GMC for service. A new battery was installed and other related operations.After about 10-15 miles, the vehicle would not start. Remote was attempted but it would not start. After about an hour, vehicle started and was driven back to Romain avoiding the stop/ start engagement.

The "Service Brake Assist" issue in other 2018 GMC SUVs is happening in the 2018 GMC Terrain, but it is not part of the recall. Our brakes became EXTREMELY difficult to press right as we were turning onto the on ramp of an expressway. Thankfully we were smart enough to pull over and not get on the highway. Had we done so, I may not have been here to type this complaint. The brakes be come extremely difficult to press and that message shows. Dealership is going to charge me $400 to replace a vacuum pump - they were not interested in the information I have around this issue in other GMC SUVs since it isn't a formal recall on the Terrain. I could have died yesterday due to this braking issue. I've owned this car for 3 months.

WHEN RESTARTING AFTER VEHICLE "AUTO STOP" I AM GETTING "SERVICE BRAKE ASSIST" AND OCCASIONALLY "SERVICE ESC" WARNINGS. THESE WARNINGS WERE ASSOCIATED WITH BRAKE FAILURE IN GM SUV'S AND PICKUPS AND WERE SUBJECT TO A RECALL. NO SUCH RECALL EXISTS FOR THE TERRAIN. I HAVEN'T YET EXPERIENCED A BRAKE FAILURE BUT GM SEEMS TO WANT TO WAIT UNTIL I DO TO FIX THE PROBLEM.

THE SERVICE STABILITRAK LIGHT CONTINUES TO COME ON. WHEN IT DOES, ALMOST ALL OF THE LIGHTS ON THE DASH LIGHT UP AND THE CAR PUTS ITSELF IN NEUTRAL AND SHUTS OFF. THIS HAS HAPPENED 5 TIMES IN THE PAST TWO WEEKS. TWICE WITH MY [XXX] IN THE CAR. PARTS OF THIS DOCUMENT HAVE BEEN REDACTED TO PROTECT PERSONALLY IDENTIFIABLE INFORMATION PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6). THE CAR WAS PURCHASED 12/23/2020 AND IT FIRST SHUT OFF WITH THE SERVICE STABILITRAK WARNING 12/31/2020. I'VE TAKEN IT TO THE DEALERSHIP FOR REPAIR. THEY REPLACED THE FRONT RIGHT WHEEL SENSOR TODAY AND IMMEDIATELY AFTER LEAVING THEIR LOT, IT SHUT OFF TWICE. I DID A SEARCH ON THE VIN AND FOUND THAT THIS VEHICLE HAD ISSUES AT 11K MILES AND 27K MILES. NOW AGAIN AT 55K MILES. THE CAR JUST SHUTS ITSELF OFF WHILE DRIVING. FIRST TIME IT HAPPENED, I WAS ROUNDING A CORNER IN HIGH TRAFFIC AND IN MID TURN, THE CAR SHUT OFF. I WAS ALMOST HIT BY SEVERAL CARS. THIS VEHICLE IS DANGEROUS. IT HAPPENED ONCE WHILE ON THE HIGHWAY WITH MY 15 MONTH OLD IN THE CAR AND TODAY IT HAPPENED TWICE WITH HER IN THE CAR.

MY 2018 GMC TERRAIN HAS MAJOR ISSUES THAT ALMOST CAUSED ME TO HIT A WALL ON THE EXPRESSWAY DUE TO A BRAKE ASSIST ISSUE THAT OTHER OWNERS HAVE A ISSUE WITH AND GMC HAS DONE NOTHING TO HELP THE BUYERS , WHERE CAN WE THE BUYERS GET HELP WITH ISSUES GMC IS WELL AWARE OF??

CAR SHUTS OFF COMPLETELY AT A STOP AND NO POWER AT ALL UNTILL IT IS JUMP STARTED.

MY CAR JUST COMPLETELY SHUT DOWN OUT OF NOWHERE. IT HAS HAPPENED TWICE WHEN I WAS SLOWING FOR TRAFFIC AND WHEN I WAS IN A PARKING LOT. THE FIRST TIME I COULDN'T GET OUT OF THE CAR BECAUSE THE DOOR WOULDN'T UNLOCK. THEN THE POWER CAME ON BUT THE CAR WOULD NOT TURN OVER. IT HAS PUSH BUTTON GEAR SHIFTS AND WOULD NOT GO INTO NEUTRAL. I HAD TO CALL THE POLICE TO ASSIST UNTIL THE CAR WAS TOWED BECAUSE I WAS ON A VERY BUSY AND DANGEROUS STREET. I HONESTLY WAS SCARED SOMEONE WAS GOING TO SLAM INTO ME. THE SECOND TIME I WAS LOOKING FOR A PARKING SPOT AND IT STOPPED. LUCKILY I ALWAYS KEEP THE DOORS UNLOCKED SINCE FIRST INCIDENT HAD TO BE TOWED BOTH TIMES. AS OF TODAY IT IS STILL AT THE DEALER TRYING TO BE FIXED FOR A SECOND TIME. THEY 'THOUGHT' THEY FIXED IT THE FIRST TIME BUT IT HAPPENED AGAIN. THE DEALER HAS HAD MY CAR SINCE OCTOBER 17. THEY CLAIM THEY KNOW WHAT IT IS. THEY REPLACE SOME ENGINE MODULE AND ARE NOW WAITING ON A PUSH BUTTON FOR THE GEAR SHIFT.

RECALL ON THE ENGINE BLOCK HEATER. THE DEALERSHIP IS UNABLE TO GET THE PART TO REPLACE. I TOOK IN OVER 6 MONTHS AGO AND STILL HAVE NOTHING.

THE SCREEN ON THE DASH WHICH INCLUDES THE RADIO AND BACK UP CAMERA GOES WHITE AT RANDOM TIMES AND DOES NOT WORK. I HAVE HAD THE RADIO/SCREEN REPLACED AND IT STILL DOES IT. I HAVE HAD MANY UPDATES WITH THE SCREEN.