2019 GMC Terrain: What to check before buying

The 9-speed transmission slips, misses third gear, sticks in first, or won't engage any gear and strands the car. Some fail within the first few thousand miles, and dealers cite a damaged valve case or planetary gear. Others won't shift into Park and show a shift-to-park message. A second pattern is the brake vacuum pump failing. That leaves a hard brake pedal at highway speed, and the pump's debris can ruin the camshaft or the whole engine. Sudden shutdowns at speed bring near rear-end collisions. Some pumps fail more than once.

The brake pedal suddenly turns rock-hard, often at highway speed, and the car barely slows. A "Service Brake Assist" or reduced engine power warning sometimes comes first, but many drivers get no warning. Shops usually find a failed camshaft-driven vacuum pump, between about 30,000 and 86,000 miles. A pump-only repair runs around $540 to $600. Bills reach nearly $4000 when pump debris damages the engine. One filing reports a crash with 3 injuries. Many owners say no recall covers the 2019 Terrain.

The backup camera goes to a blue screen with a "Service Rear Vision System" message. One owner paid over $600 to fix it after the warranty ran out. Intermittent electrical faults also appear: service parking brake and reduced steering warnings, flickering headlights, StabiliTrak lights, and an infotainment system that blasts its own volume. Some cars stall and lose all dash power. One fire-flagged report describes a chemical burning smell from the vents that gave occupants headaches. Dealers often cannot reproduce the intermittent faults.

Catastrophic engine failure is the worst pattern. A broken vacuum pump sends debris into the engine, and repairs include timing chains, cam phasers, or a full engine replacement. Two reports involve fire, including a highway shutdown with flames under the hood at 14K miles. New cars lose power under hard acceleration with misfire warnings, and one had a turbo tube blow off at 1000 miles. Other reports describe overheating with oil in the coolant and a transmission that drops into Park while driving.

The backup camera shows a blank blue screen when shifted into reverse, often with a "Service Rear Vision System" message. Reports cluster between about 50,000 and 88,000 miles. Owners and dealers tie the problem to Technical Service Bulletin 19-NA-076 and call it common on GM vehicles. One driver backed into a telephone pole at 3 mph with the camera out, shattering the rear window. Several owners have not had it repaired.

Pulling away from a stop, the wheel jerks sharply opposite the direction of the turn. Power assist can also cut out mid-turn, with ESC and service parking brake messages appearing intermittently. In one diagnosed case the steering gear was losing voltage and needed replacement at an estimated $2035.63. Other filings describe a hard brake pedal from vacuum pump failure, plus forward automatic braking and lane departure warning that don't work while the dealer finds no codes.

Warning lights for stability control, ABS, and traction control come on together with a flashing check engine light and a stored P0300 misfire code. In one case it kept recurring after a dealer update and ended in a tow. One crash report describes the car lurching forward in stop-and-go traffic while the brake pedal failed to respond, hitting the vehicle ahead. Another describes the navigation and infotainment screen shutting off with an SD card error. With only 3 complaints, there is no clear pattern.

Both complaints involve crashes with injuries, and they describe opposite failures. In one side impact the air bags deployed, but metal fragments struck the driver's face and caused severe injuries. In the other, the driver-side air bags did not deploy when the vehicle was hit on that side. Two reports are too few to show a pattern, but each describes a serious occupant-protection failure.