The National Highway Traffic Safety Administration is investigating a problem with an airbag indicator light in full GM vehicles. Officially, the "airbag malfunction indicator (MIL) illumination accompanied by diagnostic trouble codes B0001-1B or B0012-0D may result in a loss of airbag protection for the driver."

This problem could affect almost 750,000 vehicles. And as we know, airbags are crucial to surviving accidents.

The vehicles in question, according to NHTSA, are the 2020-2021 Chevy Silverado and Tahoe, GMC Sierra, Yukon, Yukon XL, and Cadillac Escalade, Escalade ESV, CT4, CT5 and XT4.

So far NHTSA has received 15 complaints, reports of six crashes or fires, and six incidences of injury. No fatal crashes have occurred.

A technical service bulletin issued in March 2021 addressed the airbag MIL illumination accompanied by diagnostic trouble codes B0001-1B or B0012-0D. It cited rust particles in the connection terminal interface of the driver airbag inflator as the cause of the light. Seeing that light "under these circumstances may result in a non-deployment of the driver airbag during a frontal collision and increased risk of injury to the driver."

NHTSA investigations start with a review of the customer complaints as well as other information related to the alleged defects. It then analyses any petitions calling for defect investigations and reviews safety-related recalls. After all of that, the investigation begins, the outcome of which will decide if a recall needs to be initiated.

All the big cars mentioned (Silverado, Tahoe, Sierra, Yukon, Escalade), from those model years, ride on the same new GMT T1XX platform, which makes us think that has something to do with it. The Cadillac CT-4 and CT-5 are on GM's Alpha platform while the XT4 rides on one called E2XX.

Hopefully this is an easy fix, because a three-quarter million vehicle recall is big job. If rust is the problem, then water is getting in somewhere. In home ownership, there's no fight to be had, because water always wins. But in this case, it could be as easy as adding some weather stripping somewhere under the hood.