Front radar sensor system malfunction mazda cx-9

Recently the brake dash light would come on when the car was first started, followed by the smart city brake malfunction and front radar malfunction warnings. This occurred intermittantly over several days. The warnings worsened, to the point that they remained on throughout a drive. Checked the usual suspects - camera issues re fogged windscreen, etc. Problem soved by the dealer. My brake pads were worn to 4 mm. The wear of the brake pads causes more brake fluid to pass from the reservoir to the lines to the point where it was below the fluid sensor in the reservoir.

Table of Contents Show

What does front radar sensor system malfunction mean?
Where is front radar sensor Mazda cx9?
Where is Mazda radar sensor located?
Where is the front camera in Mazda cx9?

I have never heard of anything like this happening before due to brake pad wears. Hopefully someone with better knowledge of brake systems will chime in, but I feel like if the issue was really low brake fluid level, then the fluid level was either too low to begin with (improperly filled) or you have a fluid leak somewhere. I recommend you keep monitoring your brake fluid level to make sure it doesn’t go down and you don’t have a leak.

I had the same lights come on yesterday. I’m at about 72k mi on original pads & rotors. I know that I need to replace at least the pads very soon.

The Smart Brake System Malfunction light came on first. It went on after I parked, shut the car off & turned it back on. A few hours later on the way home that warning came back on with a low brake fluid warning in the infotainment screen warning guidance & Front Radar Sensor System Malfunction. It also said Smart Brake System Malfunction.

I’m thinking it’s a combo of worn pads and low brake fluid. It just struck me as odd that the radar system warning would come on with the other ones. It was especially cold at 9° or so. The radar light came back on after a car wash so I know it wasn’t road grime/salt causing that.

3D5CC4EF-E678-4916-98AC-3E699A52026E.jpeg
37.4 KB · Views: 108

Also, maintenance rookie question here…

Can I just add brake fluid to the Mazda without doing anything else? I plan to get the pads replaced soon. Adding brake fluid now doesn’t cause a problem for that service, right?

Yes, a problem. As the pads wear normally the caliper pistons extend farther out toward the rotor. 100% normal. As the pistons extend farther out more fluid moves out of the reservoir and into the calipers. When new thick pads are installed the pistons are pushed back into the calipers. This moves fluid from the calipers back into the reservoir. There must be room in the reservoir for this fluid.

If the fluid level is very low, add a bit and get the brakes fixed right now. It should never get very low. When you replace the pads also replace the fluid. Fluid absorbs moisture from the air. It needs to be flushed and renewed every few years.

Yes, a problem. As the pads wear normally the caliper pistons extend farther out toward the rotor. 100% normal. As the pistons extend farther out more fluid moves out of the reservoir and into the calipers. When new thick pads are installed the pistons are pushed back into the calipers. This moves fluid from the calipers back into the reservoir. There must be room in the reservoir for this fluid.
If the fluid level is very low, add a bit and get the brakes fixed right now. It should never get very low. When you replace the pads also replace the fluid. Fluid absorbs moisture from the air. It needs to be flushed and renewed every few years.

That’s about what I was thinking. Just top it up a bit now to keep things working and have the fluid flushed when I get the brakes done. Thanks for the reply!

Your vehicle is equipped with a radar sensor (front).

The following systems also use the radar sensor (front).

Distance Recognition Support System (DRSS)
Mazda Radar Cruise Control with Stop & Go function (MRCC with Stop & Go function)
Smart Brake Support (SBS)

The radar sensor (front) functions by detecting the radio waves reflected off a vehicle ahead or an obstruction sent from the radar sensor.

The radar sensor (front) is mounted behind the front emblem.

If "Front Radar Sensor Blocked" is displayed in the multi-information display of the instrument cluster, clean the area around the radar sensor (front).

CAUTION

Heed the following precautions to assure correct operation of each system.

Do not adhere stickers (including transparent stickers) to the surface of the radiator grille and front emblem in and around the radar sensor (front), and do not replace the radiator grille and front emblem with any product that is not a genuine product designed for use with the radar sensor (front).
The radar sensor (front) includes a function for detecting soiling of the radar sensor's front surface and informing the driver, however, depending on the conditions, it may require time to detect or it may not detect plastic shopping bags, ice or snow. If this occurs, the system may not operate correctly, therefore always keep the radar sensor (front) clean.
Do not install a grille guard.
If the front part of the vehicle has been damaged in a vehicle accident, the position of the radar sensor (front) may have moved. Stop the system immediately and always have the vehicle inspected at an Authorized Mazda Dealer.
Do not use the front bumper to push other vehicles or obstructions such as when pulling out of a parking space. Otherwise, the radar sensor (front) could be hit and its position deviated.
Do not remove, disassemble, or modify the radar sensor (front).
For repairs, replacement or paint work around the radar sensor (front), consult an Authorized Mazda Dealer.
Do not modify the suspension. If the suspension are modified, the vehicle's posture could change and the radar sensor (front) may not be able to correctly detect a vehicle ahead or an obstruction.

NOTE

Under the following conditions, the radar sensor (front) may not be able to detect vehicles ahead or obstructions correctly and each system may not operate normally.
- The rear surface of a vehicle ahead does not reflect radio waves effectively, such as an unloaded trailer or an automobile with a loading platform covered by a soft top, vehicles with a hard plastic tailgate, and round-shaped vehicles.
- Vehicles ahead with low vehicle height and thus less area for reflecting radio waves.
- Visibility is reduced due to a vehicle ahead casting off water, snow, or sand from its tires and onto your windshield.
- The luggage compartment is loaded with heavy objects or the rear passenger seats are occupied.
- Ice, snow, or soiling is on the front surface of the front emblem.
- During inclement weather such as rain, snow, or sand storms.
- When driving near facilities or objects emitting strong radio waves.
Under the following conditions, the radar sensor (front) may not be able to detect vehicles ahead or obstructions.
- The beginning and end of a curve.
- Roads with continuous curves.
- Narrow lane roads due to road construction or lane closures.
- The vehicle ahead enters the radar sensor's blind spot.
- The vehicle ahead is running abnormally due to accident or vehicle damage.
- Roads with repeated up and down slopes
- Driving on poor roads or unpaved roads.
- The distance between your vehicle and the vehicle ahead is extremely short.
- A vehicle suddenly comes close such as by cutting into the lane.
To prevent incorrect operation of the system, use tires of the same specified size, manufacturer, brand, and tread pattern on all four wheels. In addition, do not use tires with significantly different wear patterns or tire pressures on the same vehicle (Including the temporary spare tire).
If the battery power is weak, the system may not operate correctly.
When driving on roads with little traffic and few vehicles ahead or obstructions for the radar sensor (front) to detect, "Front Radar Sensor Blocked" may be temporarily displayed, however, this does not indicate a problem.
The radar sensors are regulated by the relevant radio wave laws of the country in which the vehicle is driven. If the vehicle is driven abroad, authorization from the country in which the vehicle is driven may be required.

See More:

Mazda CX-9 Owners Manual > Seat Belt Systems: Seat Belt Extender
If your seat belt is not long enough, even when fully extended, a seat belt extender may be available to you at no charge from your Authorized Mazda Dealer. This extender will be only for you and for the particular vehicle and seat. Even if it plugs into other seat belts, it may not hold in the crit ...

What does front radar sensor system malfunction mean?

If you see the FCW off error, it means that the forward-collision warning light system is turned off. This can be caused by various things, such as a dirty sensor or an obstruction in front of the sensor. If you see this error, you should also check the area in front of the sensor for any obstructions.

Where is front radar sensor Mazda cx9?

Refer to Forward Sensing Camera (FSC) (Search). The radar sensor (front) functions by detecting the radio waves reflected off a vehicle ahead sent from the radar sensor. The following systems also use the radar sensor (front). The radar sensor (front) is mounted behind the radiator grille.

Where is Mazda radar sensor located?

The front radar sensor is mounted behind the radiator grille. Refer to Front Radar Sensor (Search). The front side radar sensors detects radio waves reflected off a vehicle ahead sent from the radar sensor.

Where is the front camera in Mazda cx9?

Your vehicle is equipped with a Forward Sensing Camera (FSC). The Forward Sensing Camera (FSC) is positioned near the rearview mirror and used by the following systems.

front radar sensor system malfunction mazda cx-9