During a crash sensing diagnostic modules (SDM) detect the impact and send a signal to the airbags to deploy.
But according to CarComplaints.com, the SDM in the 2018 Acadia might not be powering down properly when the SUV is turned off.
The module may stay deactivated when the SUV is restarted, showing an airbag warning light to the driver and a message that says “service restraint system." Additionally, a driver will hear warning chimes indicating the airbags are off.
Basically, if it doesn’t shut down properly it won’t be able to turn on properly the next time the SUV is restarted. If that sounds familiar, GMC was part of a massive recall for similar module problems last year.…keep reading article "2018 Acadia’s Airbags Might Not Deploy Because of Faulty Sensing Modules"
While you're probably still digesting that extra serving of holiday cookies, here's something else to chew on
– GM says some 2017 Cadillac XT5 and GMC Acadia SUVs will have diminished braking ability because of hydraulic fluid leaks. Engineers found an oversized front caliper piston bore had allowed the piston seal to leak hydraulic brake fluid and it was determined the oversized bore can prevent the proper compression of the caliper piston seal.
GM says a red "BRAKE" warning light will come on when this happens. So if you see that, stop driving as soon as possible – which in these SUVs could take quite a while. The bad caliper assemblies are on Acadias built between 04/19/2016 and 04/22/2016keep reading article "Acadia Hydraulic Brake Fluid Leaks"