"Brake System. Drive moderately" in BMW – What is Wrong and How to Fix?

The "Brake System. Drive moderately" warning message comes up when your brake pad sensor detects a problem. It may occur because of worn brake pads or because you did not reset the system after replacing them. The warning comes up when the sensor physically meets the brake pads. It may also come up because of other factors.

Brake system message highlights

• Common reasons:brake pads worn out, brake pad wear sensor faulty, ABS problems
• How to fix:check pads, check wear sensor, use scanner to get codes
• Possible consequences:brake failure is super dangerous
• Priority level:High
• Can you drive?Carefully
• DIY repair:Possible but complicated
• Repair price range:$150-$400

What Causes "Brake System. Drive Moderately," Warning in BMW?

While worn brake pads are the primary reason for this message, other factors can trigger the message. Explained below are some of the possible causes of this error message.

1) Bad Brake Pads

"Brake System. Drive moderately" warning message comes up mostly because there is a problem with your brake pads. BMW sets a minimum thickness of the pads that, once reached; the brake pad sensor issues a warning. Although it is okay to replace them, the brake pads are still usable at the time of the first warning. You can keep driving for a few more miles.

However, if the warning comes with a solid red light, the brake pads are beyond critical wear point, and you should replace them. If you do not replace them as soon as possible, you will start to hear squealing noises when you brake. As your BMW brake pads wear, the brake system sensor will also be exposed to the brake discs.

2) Your Brake System Needs a Reset

Another cause of the "Brake System. Drive moderately" error message is that your system needs a reset. Have you replaced the brake pads and sensor, and the message refuses to go away? It is because the previous malfunction status is still stored in the computer system of your BMW. Reset the brake system, and the warning message will go away.

If you try resetting and it keeps saying reset unsuccessful, chances are you did not replace the brake pad sensor. It would be best if you replaced it too. If you replace the sensor and the message still shows, ensure it is properly positioned.

Once all these factors in perfectly in place, the brake system reset should work. You may also need an OBDII scanner to reset the system by deleting all diagnostic trouble codes stored in the vehicle's computer system.

3) Brake Fluid Issues

Another reason your vehicle's ECU could sense a problem with the brake system is when the brake fluid develops problems. Your BMW has a brake fluid reservoir under the hood on the driver's side. For it to affect the brake system, the brake fluid could be low, or the reservoir could be empty. It could also contain contaminants, affecting the proper functioning of your vehicle's brakes.

The brake fluid reservoir has maximum and minimum marks. When the fluid goes above the maximum mark or drops below the minimum mark, it will cause the brake fluid sensor to detect a problem and issue a brake system warning. The brake could also contain air bubbles, confusing the system to sense insufficiency.

Any of these issues suggest you need to replace the brake fluid or top it up.

Low brake fluid levels could happen because of leaking hoses or brake calipers. You can check under your BMW for drips or puddles. If you notice these, chase the fluid hoses of each wheel from the reservoir to confirm the line causing the leak.

If everything checks out but the "Brake System. Drive moderately" warning message is still showing, check the brake fluid sensor. The sensors in your BMW are sensitive and could malfunction because of a minor issue.

4) Bad Brake Pad Sensor

Is your dashboard showing the "Brake System. Drive moderately" warning message, yet your brakes are working fine? It could be your brake pad wear sensor is faulty. Your vehicle's brake pad wear sensor is a wire that runs at the sensor's tip. When the brake pads wear out, the wire at the tip of the sensor breaks, opening the circuit and triggering the error message.

The warning message may remain on the dashboard until you replace the brake pads and the sensor and reset the brake system. If you replace the brake pads and leave the old sensor, your brakes could work properly, but the error message will not disappear.

At this point, the message is showing because the sensor is faulty. BMW designs these sensors to break when brake pads wear out. As a result, you must replace it when replacing worn-out pads.

The brake pad wear sensor could also be faulty because of other factors. As you keep using your brakes, they generate heat that can gradually damage the wiring and clips on the sensor. You can also damage the brake pad wear sensor when doing other work on your BMW, such as replacing brake discs.

Is It Safe to Drive with This Warning on the Dashboard?

The "Brake System. Drive moderately" warning message informs you that you may need to replace your brake pads. However, this being only a warning, it is safe to keep driving for a few more miles.

This applies only when the warning message comes up because of worn brake pads. This is why you should ensure you diagnose your BMW to confirm the exact cause of the "Brake System. Drive moderately" warning message. If it is due to a low brake fluid level, topping it up will fix the problem.

If the warning comes on because of a malfunctioning sensor, you should replace the affected sensor and reset the brake system.

How Long Can I Drive With This Warning on the Dashboard

As mentioned earlier, the primary cause of the "Brake System. Drive moderately" warning message is worn brake pads. If worn brake pads are the reason for the error message, you can drive for around 300 to 800 miles depending on the model of your BMW. It is better to replace the brake pads sooner.

BMW designs its brake pads to wear evenly on each side. If you continue to drive with the brake system warning still on, the brake pads will wear unevenly. The problem with this is that it can cause damage to other brake system components, such as the rotors, which could lead to more costly repairs in the future.

Another reason you should not wait until the damage becomes irreversible is that worn brake pads affect the functionality of the brake system. It makes it difficult for the brakes to bring your BMW to a stop when you need it to, putting you and other road users at risk of an accident.

What Should I Do When This Warning Comes Up?

When the "Brake System. Drive moderately" message comes up, it is a sign that your brake system has a problem. It could be a minor issue, or it could be your vehicle needs a professional mechanic. Either way, when you see this warning on your dashboard, you must immediately pull over and check your vehicle.

The following is a brief guide on what to do when this message appears on your BMW dashboard.

• If this warning message pops up when you are driving, you must stop and run a quick diagnosis of your brake system.
• The first thing to check is the tires. Check all four tires for bends or cracks. Although rare, bend wheels could cause the brake pad sensor to detect a problem and issue a warning.
• Next up: check if the brake fluid level is low. If it is, your brake fluid system leaks. Check under the car for drips from any possible place or leakage. For instance, check from below the axle or around all the wheels. If you see any of these, that is the cause of the leak.
• If all these areas are okay, start the vehicle and test the brakes' responsiveness. If they seem okay, your brake pad sensor may be faulty.
• Take your vehicle to the nearest BMW mechanic for proper diagnosis and repair.

Conclusion

The BMW "Brake System. Drive moderately" message alerts you of a problem in your vehicle's brake system. It is crucial to have at your fingertips the possible causes of this warning message. If you do, you will know where to look when this message appears.

In most cases, you can keep driving even with this warning on your dashboard. However, it is not entirely safe to do so. As such, you should maintain a manageable speed and safe distance between you and the vehicle ahead. Avoid sudden braking.

If you suspect the brake system of your BMW has an issue, consult a professional mechanic for assistance.