GM Crossovers Stuck in First Gear: Chevrolet and GMC Face Investigation Over Unusual Transmission Issue

General Motors has issued a preliminary service bulletin (PIP6100) affecting certain 2025–2026 model-year Chevrolet Equinox and GMC Terrain crossovers sold in North America. The bulletin applies specifically to versions equipped with GM’s eight-speed automatic transmission (RPO MGH). Models fitted with a continuously variable transmission (CVT) and front-wheel drive are not covered by the document.

According to the automaker, some owners have reported that their vehicles may become “stuck” in first gear. In these cases, engine RPM rises, but the transmission fails to upshift. The issue can occur after shifting the selector from Reverse to Drive when the transmission temperature is below 68 degrees Fahrenheit. No diagnostic trouble codes are stored when the problem happens.

GM engineers are currently studying the behavior of the 8T45 transmission under these conditions. The company believes that in cold weather — following a recent shift out of Reverse and with light throttle input — the system may incorrectly interpret the status of one of the clutch components, preventing a shift into second gear.

Dealers have been instructed not to replace any parts until a final solution is determined. As a temporary workaround, drivers are advised to briefly lift off the accelerator pedal, which allows the transmission to shift into second gear and resume normal operation. If the issue is confirmed and a fix is identified, the preliminary bulletin will be replaced with a formal technical service document.