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Dangerous slowdown feature in GMC Acadia

Owned a 2009 Acadia. Wife travelling at 70 mph in fast lane, vehicle went into reduced speed mode (20 mph) almost killing my wife when it basically slammed on its breaks with a vehicle behind her. Result is that the engine needed to be replaced. Got rid of the vehicle. Received a $3,500 credit. Bought a 2016 Acadia using the credit. Wife was driving the Acadia and this did the same thing going from 65mph to 20mph. GMC said it is engineered that way to protect the engine, drive train. I guess they don’t care about the driver and passengers. Anything anyone can do to file a lemon law or other class action complaint. I believe this is a serious engineering safety problem!!!

Lemon Laws apply to newly-purchased vehicles, not to those that are several years old.
Your best bet would be to file a complaint with NHTSA.

Just out of curiosity, why did the 2006 Acadia need an engine replacement?

Ed B.

I have a hard time believing that the car slammed on the brakes automatically when it went into limp home mode. Also the Lemon Laws are for defects. If GM meant for the vehicle to exhibit this behavior and it did exhibit this behavior, then it’s not a defect.

There has to be more to this story . The part about the breaks ( BRAKES ) activating in limp mode makes no sense . 3500.00 credit ? Is that a trade in amount ? And why would you buy a used vehicle of the same one you had problems with ?

+1
I have no doubt that both vehicles went into limp mode, but the probability that the brakes were activated is… extremely remote.

Sounds like the engine blew…

Paul00, you’ve given us a technical explanation that’s missing information and doesn’t make sense. Unless you can clarify what really happened with accurate details, I don’t think you’re going to get any helpful comments here. I’m also finding it hard to believe that what’s basically a once-in-a-lifetime event (that’s never been reported here by anyone else that I recall) has happened to you twice in short order.

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+1 to both comments.

Limp mode doesn’t slam the brakes on, though it would reduce speed rapidly. Was either the engine overheating and/or the check engine light flashing?

Again, I’m going to ask the same question as above…was the engine overheating and/or the check engine light flashing?

They care about the driver keeping tabs on basic maintenance, such as making sure all of the necessary fluids are at the correct level, also scanning the dash display and addressing issues if any warning or caution lights come on along with checking the temperature gauge while they drive

Lemon Law? definitely not…the vehicles are both used. Class action? highly doubtful. All vehicles will go into a limp mode depending on what is causing them (my guess is overheating engine or transmission fluid temperature being too high would be the main causes). Limp mode is so you can get to a safe place to pullover. If it would happen again, put your hazard lights on and get to a safe place as quickly as possible.

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No warning! The 2016 Acadia was at the GMC shop a week before for an oil change and check up.

When was the transmission fluid level checked last and when was it changed last?

Just curious why you purchased another Arcadia? I mean given your first experience.

Cars will automatically reduce power if the computer notices certain problems, like low oil pressure. And some cars with advanced gizmos will slow down automatically if their forward looking warning device (camera/radar/laser etc) thinks you are about to crash into something ahead of you.

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