I bought my car about a month ago I have less than 3K on it. Since DAY 1 there has been a noticeable knocking noise from back rear of vehicle, sales person said it was somebody’s radio. No it wasn’t. Next the brakes were squeaking so I took it to the dealer to get checked, it was given back as fine. Next morning I moved the car to the back of my lot and left it, came back 20 minutes later. Break hard and doesn’t allow me to start. Starts on remote start though. I get codes saying smart brake malfunction brake malfunction, now I have many warning codes in the app.

Current warning codes in app

Warning codes from app

Most recent warning

 

Have Mazda Roadside Assistance (free to owners) tow your CX to a dealer - preferably not the clueless dealer you used before.

 

It will be kind of hard for them to say it's "fine" now - won't it? Probably a bad sensor and a quick fix. Let us know what happens.

 

What did the issue end up being? Just had the exact same thing happen to my 22 CX-5 Signature. It was completely out of the blue and we're on a trip away from home. I'm about to disconnect the battery and reset things but I just wanted to see what your solution was. I'm sure this thing will have to get towed.

 

Why in the world would you want to do this to a vehicle under full warranty? Mazda will need the codes and diagnostic information, and you want all of this to become part of the permanent history of the vehicle, regardless what action Mazda takes right now and what the outcome of this incident turns out to be. Just do what your car is telling you to do.

 

I’m not sure if you’ve been on a road trip with a family of four when you’ve had an issue like this with no Mazda dealer around so before I go through a nightmare to get the car to a far away dealer and end the trip, I was merely inquiring if the OP found it to be a sensor misfire or something that cleared up on its own. Assuming that’s not the case, yes, I’m going to have to take it in at least to an indy around here but it doesn’t hurt to see what others ended up experiencing. I’ve owned cars that have had a sensor misfire that caused similar issues that cleared up on its own.

 

I also have a family, and fully understand how unhappy of a situation this is for you. It's very unfortunate and inconvenient, but you also need to consider how best to protect your very big investment. By immediately contacting the nearest Mazda dealer and provide the error messages along with your situation, IMO its highly likely they will get authorization from Corporate (or make the decision on their own) to get you into a rental, along with a tow of your vehicle at no cost to you. If I was in your situation I would definitely call Mazda before disconnecting the battery, or anything else for that matter.

 

The hit-and-run OP hasn’t been back to the forum since the day he first posted. Don’t waste your time asking him for an answer…..

 

I thought I'd follow up in case someone runs across this issue in the future. All the errors were due to a dead battery which had no reason to die since the car only has 800 miles on it and nothing in the vehicle had been left on. We had been driving it that day without issue when it all of a sudden failed to start after a very short rest. The dealership was stumped too and hypothesized that the battery was defective as the alternator and everything else was working fine. Apparently defective batteries are not uncommon. So if the car is newer, the first thing to do is request a battery replacement under warranty.

 

Definitely not uncommon. Especially today. Things are not made like they used to be.