2021 Chevrolet Trailblazer: What to check before buying

Most reports involve the shifter not registering Park. The "Shift to Park" or "Vehicle Not in Park" message stays on, the engine keeps running, and the doors will not lock. On cars with a traditional key, the key can stick in the ignition. Dealers usually replace the shifter assembly, with failures reported around 35,000 to 40,000 miles. A second group describes transmission trouble: slow engagement into Drive, sudden loss of power, and stalling in traffic. Some reports describe reduced engine power traced to the turbo. One report describes a fire after a deer strike.

The "Shift to Park" fault shows up here too. The car stays in accessory mode, drains the battery, and sometimes fails to detect the key or shuts off while driving. Infotainment and OnStar module failures take out the radio and backup camera. An amplifier failure can silence the collision warning chime. Other reports describe a sudden loss of electronic brake assist with traction control and lane-keep warnings, stalling with a "Engine Power is Reduced" message, and repeated failures of the starter, alternator, and fuse box. One car caught fire after a collision.

The most common complaint is a check engine light with a "reduced engine power" warning that limits acceleration on the highway. Shops trace it to the turbocharger or wastegate, with reports between 47,000 and 90,000 miles, and some cars keep the fault after the repair. Coolant control valve failures cause overheating and a fan that runs after shutdown. Evap purge pump codes (P1467) appear, and one car shut off at highway speed. Further reports describe fuel pump failure, catastrophic engine failure, an exhaust that came loose, and a fire with no warning lights.

Loud squealing at low speed and in reverse is the most frequent complaint, and it often starts within days of delivery. Dealers tend to call it normal and decline to fix it. More serious reports describe brake failure messages, a pedal that sinks to the floor, ABS and StabiliTrak warnings, and brakes that need full force until the car is restarted. One car showed a warning that speed was limited to 53 mph. Two crashes with three injuries are reported, including one where automatic emergency braking did not activate.

Water gets into the cabin. Owners describe water in all four door panels, standing water in the spare tire well, and wet rear seats growing mold. One dealer called the door-panel leak common, at 23,520 miles. The panoramic moonroof can shatter at freeway speed with a gunshot-like bang. A power liftgate that opens and closes by itself struck one owner on the head. Other reports include peeling hood paint, missing fender clips, and a loose front bumper.

A "Service Power Steering" warning tends to appear together with brake failure or ABS alerts, after which the brakes need much more pedal force. In one crash the car would not turn or slow, ran through an intersection, and ended up in a snowbank. Another car had these warnings at only 160 miles. Some cars show the light on and off without other symptoms. Other reports describe reduced speed and repeated misdiagnosis, with fuel injectors replaced before the turbocharger was blamed.

A leaking fuel rail causes a strong gasoline smell under the hood, and the fumes reach the cabin. Mechanics have called the car unsafe to drive because of fire risk. Leaks appear just past the warranty, with one report at 29,000 miles, and owners quote repairs of about $2000 to $3k. One leak returned months after the dealer repair. Other owners report an evap purge pump code (P1467) along with fuel or engine smells inside the car.

Sudden unintended acceleration is the main concern. One car surged while parking at 5 mph, jumped a median, and hit a building, causing an injury. Another surged from 50 to about 80 mph several times and only stopped after being shut off. Dealers report finding no fault. A separate report describes cruise control and auto start not working, with codes P0700 and P1467.