Mazda CX-9 Beeping? (10 Common Causes)

The CX-9 is one of Mazda’s most popular choices.

It uses various beeps, chimes and noises – although sometimes these can be for unknown reasons.

If your CX-9 keeps beeping and you’re unsure why, we’ve got the answers for you here.

Why Is My Mazda CX-9 Beeping?

Random beeps from a Mazda CX-9 can be caused by: key fob left in car, navigation software issues, navigation alerts ( red light cameras etc.), faulty CMU, car not in Park, low key fob battery, weight on the passenger seat, and issues with the airbag system.

If your CX-9 keeps beeping at you there could be a number of possible causes, we’ve outlined the most common ones below.

1. Mazda CX-9 Beeps When Locking – Key Fob Left In Car

A very common reason why you may be hearing a mysterious beep from your CX-9 after locking it, is because you have a spare key in the vehicle. The warning beeps are designed to let you know you have left a spare key in the car.

This is a common feature across many Mazda models.

Here’s what the manual says:

Key Left-in-vehicle Warning Beep (With the advanced keyless function)

If all the doors and luggage compartment are locked using another key while the key is left in the cabin, the beep which sounds outside of the vehicle will be heard for about 10 seconds to notify the driver that the key is in the cabin. In this case, take out the key by opening the door. A key taken out of the vehicle using this method may not operate because its functions have been temporarily stopped. To restore the key’s functions, perform the applicable procedure. 

There might be a spare set dropped behind the dash, under the console or somewhere hidden.

If you suspect its a lost key in the car, but you just can’t find it:

  • Have an auto locksmith erase all the keys stored and program the key fob you have.
  • If the beeping stops there is a key in the vehicle somewhere.
  • Should you ever find the key, it can be reprogrammed to the car.

2. Mazda CX-9 Beeping While Driving – Navigation Alerts

A number of CX-9 owners have reported hearing mysterious beeps when driving. These are usually caused by red light warning beeps, these can be disabled via the Navigation system, simply go to the alerts section and untick red light camera warning.

One owner from explains hearing the beeps:

“Every once in awhile our 2013 cx-9 beeps three times from the left side of the dash. When this happens it is always three beeps and then silence. We have had this happen at the same locations along certain sections of freeway or intersections. Very odd to say the least! Anyone out there knowing what, where or why this occurs we really would like to know!”

Another owner chimed in with the solution:

“Presuming you have a navigation system, go to the alerts section and unclick the red light camera warning signal to see if that eliminates your mystery beeps. I get a bing, bing, bing when approaching the same intersection and when passing over the same intersection on the freeway. I had inadvertently turned the signal on when poking around my first navi system on my 2015 GT.”

To which the owner replied:

“Good grief!!! I had the same beeping! I just checked the settings in Navigation and yup, the red light camera alert is on! I was going to turn it off, but you know what? Now that I know what it is, I feel better, LOL! Thankyou thankyou thankyou!!!!!”

3. Mazda CX-9 Beeping While Driving – Navigation Glitches

Navigation Sounds

If you’re hearing random beeps whilst driving your CX-9, it could be linked to glitches in the Navigation system. A number of Mazda owners have reported being able to band-aid the issue by turning off the navigation sounds – however, performing a Factory Reset has worked for a number of owners to permanently fix the issue.

The issues have been attributed to a firmware bug in the Mazda Infotainment/Navigation – which might be fixable with a software update.

Similar issues have been reported with other Mazda models such as the CX-30, CX-5 etc.

Here’s what Mazda owners on Reddit had to say:

“In summary it kinda looks like once you toggle it on/off for alerts and audible it can potentially glitch out. The factory reset works to resolve and you’ll get the visual alerts back straight away.”

“Frustrating issue for sure that seems to need a software update to truly fix, but I don’t know how common it is. Factory reset as suggested is ultimately what fixed it for me some time ago. It’s a minor PIA to reset a few things but at least I can drive in peace now.”

Navigation SD Card

A number of Mazda SUV owners have reported that mysterious beep sounds have gone away after removing the SD Navigation Card. However, if you eject the SD card, things like speed limit, stop sign recognition, lane keep and the speed limits showing on the HUD may no longer work. You can also try muting the Navigation which may work too.

4. Faulty CMU

If you are hearing random beeps or chimes it may be caused by issues with the Connectivity Master Unit.

The CMU controls systems such as communication between mobile devices, Bluetooth, and the sending/receiving of video/audio signals from units related to the entertainment system.

You will need Mazda engineers to carry out some diagnostic tests; should the CMU you be faulty you can simply have it replaced.

5. Car Not In Park

The CX-9 will sound a warning beep if it’s not in ‘Park when you lock it.

Some Mazda owners have also reported failure/sometimes failure of the switch in the console that registers when the car is in park, thus causing mysterious beeping.

6. Low Key Fob Battery

Random or unknown beeps on a CX-9 can often be attributed to a low key fob battery.

It might be worth replacing the battery to rule out this possibility as they are fairly cheap although it is advised to get a good quality battery.

Ensure the fob is clean inside (you can remove dirt with a cotton swab and some rubbing alcohol).

7. Weight On The Passenger Seat

A common cause of mysterious beeps on a CX-9 is weight on the passenger seat.

This could be a bag, a laptop, a bottle of water or even your pet pooch.

The car thinks your passenger needs to buckle up and thus issues a warning beep.

Try fastening the passenger seat belt to see if the beeping stops.

Related: 17 Best & Worst Mazda CX-9 Years (With Pictures)

8. Airbag Problems Warning

According to the Mazda CX-9 owners manual, a warning beep will sound if there is an issue with the air bag/front seat belt pretensioner systems.

Here is what the manual says:

If there is a problem with the air bag/seat belt pretensioner systems and the warning light illumination, a warning beep sound will be heard for about 5 seconds every minute.

The air bag and seat belt pretensioner system warning beep sound will continue to be heard for approximately 35 minutes. Have your vehicle inspected at an expert repairer, we recommend an Authorized Mazda Repairer as soon as possible.

9. Mazda CX-9 Not Beeping When Locked

If you’re CX-9 is not beeping when you lock it, this is most probably caused by the trunk not being shut properly, or one of the doors not being shut completely.

Here’s what Mazda owners on had to say:

“I had this exact problem 2 days ago, turned out my trunk was not fully closed, when I pressed “lock” there was no beep or flashing lights. Then I made sure to slam all the doors, engine hood and trunk shut, then it worked….”

“Thank you so much!! I just went out to check….and I opened and slammed close every door and the hatch (hatch seemed closed but I guess not). Now the vehicle beeps / honks when pressing the lock button on the fob. Lesson learned….sometimes doors / hatch seem closed but they are not fully closed.”

10. Malfunction of the Keyless Entry Unit

This is quite rare although it can happen – if you have faults with the keyless entry unit then you will likely hear random beeps.

If you suspect his is the case, speak to your dealer and have them run some diagnostic tests.

What Does Mazda Say?

Mazda gave the following reasons as to why you might be hearing a beeping sound:

  • One of the doors is open
  • Emergency brake is on
  • Certain dashboard warning lights are illuminated
  • Blind Spot Monitoring
  • Low tire pressure
  • Ignition not switched off
  • Driver’s seat belt not fastened
  • Air bag problem
  • Dashboard dimmer knob is in maximum dim position

Alternative Suggestions For Beeping Problems

Disconnect the Battery

Disconnecting the battery for 20 minutes may reboot some of the cars electrical settings and could potentially clear out some electrical glitches.

Check the Dashboard for Warnings

When the beeping occurs can you see any lights come on at the same time on the dash?

This can give a big clue as to what’s causing the beeping.

Take it to a Mazda Dealership

If needed, take your car to the dealership.

Tell them you are NOT paying for a check on what the problem might be.

Ask them if they will check it for free.

Most dealerships and other places do quick/initial diagnosis for no money as they plan to make money for the repair of your vehicle.

Check for Recalls or TSBs:

By entering your vehicle’s VIN number on Mazda recall page you can determine whether or not there is a recall for your vehicle and if there is you’ll want to get it fixed.

Similarly, a quick Google search will help you determine whether there is a Technical Service Bulletin for your Mazda.

These are less serious but may give a reason why your vehicle is beeping.

A recall is issued by a vehicle manufacturer for issues that are safety-related, while a TSB covers components that may be malfunctioning but don’t compromise the safety of the vehicle.

Related: 9 Most Common Mazda CX-9 Problems (Explained)



  • Ian Sawyer

    Growing up with a father who was a mechanic I had an appreciation for cars and motorcycles from an early age. I shared my first bike with my brother that had little more than a 40cc engine but it opened up a world of excitement for me, I was hooked. As I grew older I progressed onto bigger bikes and...