Mazda CX-5 Won't Start, Brake Locked - What's Wrong?

Your Mazda CX-5 seems like a great buy. It's a cool-looking SUV with quite a lot of tech for pretty reasonable money. If you try and compare the new CX-5 with something else on the market, you will see that the Japanese compact SUV is one of the best offers for this money. And despite the design having been here since 2017 with a light facelift in 2021, the vehicle still seems to look cool.

No-start and stiff brake problem highlights

• Level of urgency:Medium
• Can you drive?Obviously, no
• DIY inspection:Possible
• DIY repair:Impossible
• Price for repair:$350 - $800
• Common Reasons:Engine won't start, vacuum won't build up
• Ways to fix:Solve the no-start issue, thebrake pedal will be solved automatically

Here's how your Mazda CX-5 may refuse to start one day

Before we offer some solutions, let's check if we are on the same page with you. The issue that we are talking about today may happen spontaneously in a Mazda CX-5 and it may also be OK after some time. It may not, and then you will need professional help right away. But in most cases, the car will eventually start after several tries.

Also, this problem may affect the brake pedal - it seems blocked and you can't press it. Though you should also check if the pedal feels different from what it usually feels. In any car, the brake pedal will feel hard until you start the engine and the vacuum system starts working.

So, here are the symptoms of the problem:

• you get into your Mazda CX-5, press the brake pedal, push the start button, or turn the key;
• the electrical systems seem to work well - everything lights up and even the radio can be turned on;
• but the engine is silent - it isn't cranking and isn't trying to start;
• you may hear some strange clicks or hear just nothing when you push the start button;
• you can turn on the accessory mode but the vehicle still won't start;
• after pushing your start button several times, the car will eventually start;
• it may take you 10-15 minutes to start the engine when this happens;
• also, you feel that the brake pedal is abnormally hard to press down;
• it just isn't moved at all and this feels like one of the problems with the vehicle.

It's important to notice that the lights are working, you can turn on accessory mode with the push start button, and you can turn on the radio. This proves that the battery is OK and the button didn't lose any connections.

You may expect the brake pedal to be hard to push when the car isn't started yet, but it shouldn't feel as if it's blocked. So, something is obviously wrong with the vehicle.

The quick tip: push the button every minute and try to start the engine. Eventually, it should start. But if you are trying it for over 15 minutes, there is little chance you will succeed in this. So, just follow the tips in this article to get your Mazda back on the road.

What engines are affected?

New Mazda vehicles all come with two types of engines: a 2.5L non-turbo base engine and also a 2.5L turbocharged powerplant. Both come with the only option of the transmission - the simple 6-speed automatic transmission. Also, all come with all-wheel drive. Both engines of the CX-5 may be affected by this issue.

Today, all new Mazda CX-5 cars come with keyless access, so all trims are affected by this common problem. Earlier, cheaper trims were equipped with the simple key-start system and those only sometimes had issues with engine startup. So, in most cases, we are talking about the CX-5 models with push-button start and keyless entry.

The ignition-cylinder version can also have startup problems but the symptoms and the reasons will be different. Almost everything we'll tell you later in this article is true for keyless-entry versions of the CX-5 SUV.

What are the reasons and fixes for this issue?

We've checked this up with Mazda dealership mechanics and several other experts. Also, we've investigated this issue in specialized forums and have spoken to Mazda CX-5 owners. The information given below will help you diagnose and probably even fix your vehicle without going to the dealership. But sometimes, you will still need professional help.

Here's what could've happened with your Mazda CX-5:

1. Key fob battery issues

First of all, you should check or better just replace the key fob batteries. Also, you can take the second key fob that is probably hidden somewhere in your house. This may help you start the car and get it on the road easily.

In most cases, the reason for the problem is the battery in your fob. But sometimes, we've also seen issues with key fob programming. Mazda key fobs may lose some of their settings when the battery is removed. So, take it to the dealership and ask them to reprogram the fob.

2. 12V battery problems

Your car may not be able to start the engine because of the low battery. This is a common problem for vehicles that are mainly used in city traffic with short rides. Also, start-stop vehicles suffer from battery issues a lot.

Check the 12V battery, use the charger to check its life, and maybe add some juice to it. Or you may want to just replace the battery and see if this is the reason for the problem. If you have been using the same 12V battery for the last 4 years, this is most likely the main reason for the no-start issue.

3. Brake switch issues - quite common

Mazda CX-5, like nearly all other modern Mazda cars, may develop a brake switch problem. It means that your car will not know when you put the brake pedal. It can cause some bad safety issues, but one of the main problems is that the car won't start. Unless you press the brake pedal, you will not be able to start the engine with a button or with a key.

Checking the brake switch is pretty complicated, so you better leave it to professionals. Replacing this part is not hard and long, so labor costs are surprisingly low and the cost of the switch itself is pretty reasonable.

4. Wiring issues

Mazda CX-5 can develop wiring issues. Wires can be poorly connected in different units like the push-start button, brake system, ECU, starter, 12V battery, etc. Checking this is not easy, too, so we would have the vehicle inspected by professionals. Repairing bad wiring can be hard and expensive, but this is more about your luck.

5. Limp mode or ECU issues

ECU may block your vehicle from starting because of some bad error code that was previously registered by the vehicle. If this happens, the car will act like normal and then won't start, and won't crank the engine.

You may try taking terminals off the battery for five minutes to reset the ECU and then starting the vehicle again. If this doesn't work and you see the check engine light on the dash, you should have the vehicle diagnosed with a scanner.

6. Cold temperature issues

Mazda vehicles don't really like cold temperatures and may throw all types of errors when you leave them outside for a long time and it's freezing. Dealers don't say directly that the problem is in some hydraulics systems but mechanics silently agree this can be the issue.

Also, cold temperatures may degrade your 12V battery faster. If the key fob also rests in a cold place, its small battery may lose voltage very fast and cause this problem in the morning.

Preventing the no-start problem with your Mazda CX-5

When it comes to mechanical issues or wiring, there is no way you can prevent the problem. But in terms of batteries and also bad routine in how you use your vehicle, you can do something.

Here are the things you should regularly do to prevent your Mazda CX-5 from the no-start problem:

• check and change fob batteries every year - they should deliver over 3 volts at all times;
• check your 12V battery every year and replace it at least once every 5 years;
• avoid leaving your Mazda CX-5 in a very cold place for longer than 2-3 days without starting;
• make sure your starting routine is OK and doesn't damage your car;
• immediately address all possible problems with your vehicle, especially if it throws some codes and lights.

So, proper maintenance and a little TLC can help you avoid this problem. If you can't locate the reason for this issue, just have your vehicle inspected by professionals.