Why does it say my parking brake is on when its not?

The warning usually means there’s a fault in the parking brake system or its sensor rather than a truly engaged brake. In modern cars with electronic parking brakes, the light can stay on or appear even when you’ve released the lever or switch due to a sensor, wiring, or control issue.

Several factors can trigger the message, including faulty switches or sensors, electrical problems, hydraulic actuator faults, low brake fluid, or software glitches in the parking brake controller. If the warning persists, it’s a signal to have the system checked to avoid potential braking problems or unintended engagement.

Understanding the warning light and its implications

Automakers differentiate between a brake warning that means the system is actively engaged and a fault indicator that points to a problem in the parking brake or braking network. The exact symbols and meanings can vary by make and model, especially between traditional mechanical handbrakes and newer electronic parking brakes (EPB).

Common causes of a false parking brake warning

Before listing the potential culprits, it’s useful to group them into mechanical, electrical, and hydraulic categories. The items below cover the most frequent scenarios encountered by drivers across different car brands.

• Faulty parking brake switch or sensor (including the position sensor in an EPB system) that falsely signals “on.”


• Electronic parking brake (EPB) actuator or motor failure, or a sticking/sluggish actuator.


• Wiring harness damage, loose connectors, or corroded grounds affecting the parking brake circuit.


• Parking brake actually engaged due to a stiff or misadjusted lever (in vehicles with a traditional handbrake) or a partially engaged EPB that hasn’t fully released.


• Low brake fluid level or a hydraulic fault in the braking system that triggers a general brake warning.


• Faults in ABS/ESC or other brake-system warning codes that cause the dashboard indicator to illuminate.


• Electrical or software glitches in the vehicle’s control modules that misreport the brake status.

In practice, the light is often triggered by a combination of sensor or wiring issues rather than a simple physical lock on the brakes. If the light stays on after you’ve released the brake, it’s a signal to have the system inspected by a professional.

How to diagnose safely

Before you begin any checks, ensure you’re in a safe, level location and avoid driving aggressively if the brake warning is lit. The steps below can help you identify simple, non‑invasive causes and decide if professional service is needed.

1. Confirm the parking brake is fully released: visually check the lever position or ensure the EPB switch is off, and verify the dashboard indicator shows released status.


2. Check for a sticking or binding brake: gently feel for any resistance or unusual drag when attempting to move the vehicle with the transmission in a safe gear and the brake released.


3. Inspect the brake-fluid level and look for leaks at the master cylinder and brake lines. A noticeably low level can trigger warnings unrelated to the lever position.


4. Use an OBD-II scanner capable of reading EPB/ABS codes to pull any stored fault codes. Record codes and consult your service manual or a technician for interpretation.


5. Review recent service or software updates: a miscalibrated EPB module or outdated software can cause false warnings; check for manufacturer service bulletins or recalls related to your model.

If the warning persists after these checks, or if you notice any changes in braking performance (longer stopping distance, soft pedal, or unusual noise), stop driving and arrange professional inspection promptly. EPB systems, in particular, may require calibration, actuator replacement, or software updates.

What to do next if the light won’t reset

Persistent or worsening brake warnings should be treated as a safety issue. Do not ignore the light, especially if you notice changes in braking feel or if the vehicle feels different to slow down. Contact your dealership or a qualified mechanic to diagnose the fault, verify there’s no actual engagement of the brakes, and determine whether a repair, part replacement, or software update is needed.

Summary

A parking brake warning that appears even when the brake isn’t engaged is usually caused by sensor, electrical, or hydraulic issues in the parking brake system, rather than a truly active brake. Common culprits include faulty switches or EPB actuators, wiring problems, low brake fluid, or software glitches. A careful check using basic visual inspection, fault codes, and manufacturer guidance can often reveal the cause, but persistent warnings should be evaluated by a professional to ensure safe operation.

What would cause the parking brake light to stay on?

If your brake service warning light is always on, it could be due to a need for parking brake adjustment, worn brake pads, or hydraulic issues. If your brake service warning light turns on when you hit the pedal, it could be due to hydraulic loss on one side of your vehicle or low brake fluid in the master cylinder.

How to reset parking brake sensor?

To reset a parking brake sensor, try the following methods: manually operate the parking brake (engaging and disengaging it a few times), disconnect the car's battery to reset the electronic system, or use a diagnostic scanner to clear the fault codes. If these steps don't work, there may be an underlying mechanical problem, such as low brake fluid or a faulty actuator, that requires professional diagnosis. 
Method 1: Manually operate the parking brake
This method cycles the system and can sometimes reset the sensor. 

1. Make sure your car is parked safely.
2. Press the parking brake button or pull the lever.
3. While the brake is engaged, firmly press the brake pedal.
4. Release the parking brake.
5. Repeat this process several times to see if the warning light turns off.

Method 2: Disconnect the vehicle's battery 
This forces the car's computer to reset. 

1. Turn the vehicle off and pop the hood.
2. Locate the negative terminal on your battery and disconnect it.
3. Wait a few minutes.
4. Reconnect the negative terminal and start the vehicle to see if the warning light has cleared.

This video demonstrates how to reset the electronic parking brake without a scan tool: 59sIFIXMINIYouTube · Sep 9, 2021
Method 3: Use a diagnostic scanner 
If you have access to one, this is the most direct way to clear electronic fault codes.

1. Connect the scanner to the vehicle's OBD-II port, which is usually under the dashboard. 
2. Follow the scanner's instructions to read fault codes. 
3. Access the "Electronic Parking Brake" or similar menu and clear the code. 

When to seek professional help
If the light remains on after trying these steps, there may be a more serious issue.

• Low brake fluid: Check the brake fluid reservoir and fill if needed. If you constantly have to add fluid, there may be a leak. 
• Faulty actuator: The electronic parking brake actuator is a common point of failure. 
• Other system issues: A mechanic can properly diagnose and repair any mechanical or electrical problems. 

Why does it say my parking brake is on when it's not?

The parking brake light may stay on even if the brake is off due to a few common issues: a faulty or misadjusted parking brake switch, a low brake fluid level, or a problem with the brake fluid level sensor. It's important to address this, as the light can also be a general warning for your car's entire brake system, which requires attention. 
Possible causes and solutions

• Parking brake switch: This is the most common culprit. 
  • Cause: The switch itself can fail, or it may be misaligned. If you have a hand lever, the lever might not be fully disengaging. If you have a foot pedal, the rubber stopper under the pedal might have worn away, leaving the switch exposed and "on". 
  • Solution: Check that the parking brake lever is fully disengaged. You can try wiggling it to see if the light turns off. If not, a mechanic may need to adjust, clean, or replace the switch, which is usually located under the console or dash. 
• Low brake fluid: Some vehicles use the same light to indicate low brake fluid, not just a parking brake issue. 
  • Cause: The brake fluid level is below the minimum, which can trigger a sensor. 
  • Solution: Check your brake fluid reservoir under the hood. If the fluid is low, add the correct type of brake fluid to the "max" line. YouTube. 
• Brake fluid level sensor: The sensor in the brake fluid reservoir can malfunction or have a loose or corroded wire. 
  • Solution: Have a mechanic inspect the sensor and its wiring for any damage. 
• Wiring or other electrical issues:
  • Cause: There could be a short or other fault in the wiring of the brake light system. 
  • Solution: A professional diagnosis is needed to trace and fix electrical problems. 
• General brake system warning:
  • Cause: The same light can indicate a problem with the main brake system, such as ABS issues or a leak. 
  • Solution: If the light does not go off after checking the simple issues, have your entire brake system inspected by a professional immediately to ensure safety. 

Why does my parking brake turn on automatically?

Your parking brake may turn on automatically due to system settings for safety on inclines, or it could be a sign of a malfunction. Common reasons include the car being on a hill, the auto-hold feature being engaged, or it engaging automatically when you shift into park and turn off the engine. 
Normal automatic engagement

• Auto-hold feature: Many modern cars have an "auto-hold" system that automatically engages the parking brake when you come to a complete stop. It often will also engage the parking brake automatically when you turn the car off, especially on an incline. 
• Parking on an incline: Even without auto-hold, many electronic parking brakes are designed to automatically engage when the car is parked on a slope to prevent it from rolling. 
• Shift to park: Some vehicles automatically engage the parking brake when you put the car in "Park" mode and turn off the engine. 

Potential issues and troubleshooting

• Automatic Emergency Braking (AEB): If your car brakes suddenly while you're driving, it could be the AEB system, which is a safety feature designed to prevent collisions. This is different from the parking brake and could be a sign of a sensor issue. 
• Incorrectly shifting: Some drivers have reported their parking brake engages automatically if they try to shift into park while the vehicle is still moving. 
• Malfunction: If the brake engages randomly, at odd times, or even when it's not on a hill, there could be a malfunction. A failing parking brake might show signs like the brake warning light staying on even after you release it. 
• Check your settings: Look for a button labeled "Auto Hold" or a similar setting and check if it's enabled. You can also refer to your owner's manual for specific information on how your car's electronic parking brake works. 

What to do next

• If the automatic engagement happens on inclines or when turning the car off, this is likely a normal function. You can usually manually disengage it with a button on the dashboard or console. 
• If the brake is engaging unexpectedly or without a clear reason, it may be best to consult your owner's manual or have your vehicle inspected by a professional.