NHTSA Complaint #11442967 — 2019 GMC TERRAIN

I received a "service brake assist" message which came on then off. Took the car to a local mechanic who looked it over and said to see dealer as they saw nothing obvious. internet search revealed that many people with terrain said this warning came on when battery was low. Made a service appt for NJ dealer for 12/6/21. on 12/3/21, began a 1200 mile drive from Florida to NJ, after 2 hours, check engine light came on. Took the exit ramp from I 75 and at end of ramp, there was a total braking failure. I had to press very hard to eventually stop. Shut off car, attempted to restart but it would not. Towed to a mechanic who found fluid leakage and a repair bulletin on GM site involving vacuum seal camshaft. #pip5598A diagnostic tip. Internet search reveals many anecdotal instances of same problem. On Monday, 12/6/21, I received an email from GMAC saying that the on board diagnostics had shown a "low battery" concern. The catastrophic loss of braking seems to be connected to a low battery situation. This needs to be looked into by NHTSA.