Chevrolet Bolt 2027 windshield rattle: bulletin 26-NA-201 and the factory fix

© A. Krivonosov

Two felt squares measuring just 6.5 x 6.5 mm are GM's factory remedy for one of the first comfort issues reported on the 2027 Chevrolet Bolt. Technical Service Bulletin 26-NA-201 covers a rattle from the windshield area that can appear over uneven roads and is not tied to any particular vehicle speed.

The sound does not come from the glass or the suspension. According to the bulletin, an insert in the cover of the multifunction sensor bracket behind the rear-view mirror can become loose. A technician must first make sure there are no other unsecured parts nearby. If the play is in the insert itself, it is removed and two pieces of felt or flock tape, each 6.5 x 6.5 mm and 1 mm thick, are fitted to its front tabs.

The vehicle is then reassembled and checked again for noise. The procedure does not call for replacing the windshield, sensors or bracket. That makes this primarily an assembly and NVH issue involving cabin noise and vibration rather than a mechanical or electrical fault.

This bulletin should not be confused with a recall. No separate safety recall has been announced for this rattle. The 2027 Bolt is covered by NHTSA recall 26V114, GM number N252540430, but that campaign concerns an incorrectly configured radio module that could prevent the electronic owner's manual from downloading. The campaign includes 117 Bolt vehicles. Dealers are instructed to reconfigure the radio so the system can automatically download the owner's manual.

This is also not the model's first service action. In July 2026, GM expanded Service Update N262559000-01 for certain Bolt vehicles whose software could drain both the high-voltage battery and the 12-volt battery. The original N262559000 action was issued on June 11 for 345 vehicles; the July revision expanded the affected VIN population and added reprogramming of the Battery Energy Control Module. This action is not classified as a safety recall either.

The new Bolt's core specifications remain competitive. Chevrolet officially lists a 65 kWh LFP battery, 210 hp, an EPA range of 262 miles, or about 422 km, and DC fast charging at up to 150 kW.

For an owner, bulletin 26-NA-201 is mainly a useful diagnostic reference. If the rattle is concentrated near the rear-view mirror and appears on rough surfaces, it is worth giving the dealer the bulletin number directly. There is little reason to dismantle the sensor cover at home: the factory procedure calls for checking the fasteners first and only then adding the damping tape.