What to do if the electronic parking brake will not disengage?

In most modern cars, the electronic parking brake (EPB) replaces the hand lever with a switch or button. If it won’t disengage, the vehicle should be treated as immobile and safety steps should be taken. A safe approach is to attempt the standard release procedure first, then seek professional help if needed.

The issue can stem from electrical faults, control software, hydraulics, or a mechanical binding in the brake calipers. The following guide explains immediate safety steps, common causes, and how a technician will diagnose and fix the problem, without risking damage to the braking system or you and others on the road.

Common causes of EPB failure

Several issues can prevent the EPB from releasing. Understanding common causes can help you communicate symptoms to a technician and avoid unnecessary risk.

• Weak or dead 12-volt battery or charging system affecting the EPB module.


• Faulty EPB switch, actuator, or control module.


• Hardware binding or corrosion in the rear calipers or cables (where applicable).


• Electrical wiring damage, loose connectors, or blown fuses in the EPB circuit.


• Hydraulic or brake-fluid-related issues in vehicles where the EPB works with hydraulic pressure.


• Software/ECU fault or error codes that disable the release mechanism.


• ABS/ESC interference or a service light indicating a broader brake system issue.

These possibilities highlight why proper diagnosis is essential and why attempting DIY fixes beyond basic release is not advised.

Immediate steps to try if the EPB won’t disengage

These steps are intended to keep you safe and help you regain control without risking damage to the brakes or undercarriage.

• Safely steer to a safe location, switch on hazard lights, and, if possible, place the transmission in Park (or the vehicle’s equivalent) while keeping the EPB engaged.


• With your foot firmly on the brake, press and hold the EPB switch or button to attempt a release. Some cars require pressing the pedal while operating the switch; follow your owner's manual if possible.


• If nothing happens, try cycling the ignition: turn off, wait a few seconds, turn back on, and attempt the release again.


• Check for a manual emergency release if equipped. The location varies by model and is usually described in the owner’s manual; attempting to release this way should be done cautiously and only if you know the procedure.


• Do not attempt to drive the car with the EPB still engaged. If you must move for safety, arrange for roadside assistance or towing.

These steps prioritize safety and provide a path to regain basic control. If the release remains stuck, professional service is required.

What a technician will check and how you can help

When you reach a mechanic or dealer, they will diagnose the EPB problem using diagnostic tools and a physical inspection. Providing clear information helps speed the process.

• Read fault codes with an OBD-II scanner to identify EPB errors, sensors, or ECU faults.


• Inspect the EPB actuator, switch, wiring, fuses, and the electrical supply.


• Test the hydraulic system or brake caliper for binding or leaks; verify proper pressure to release the brake.


• Check for software updates or recalls related to the EPB control module.


• Confirm battery health and the charging system if electrical power is insufficient to operate the EPB.

A professional assessment will determine whether a simple reset, part replacement, or software update is required, and whether a tow is necessary.

Emergency release: model-specific guidance

Some electronic parking brakes incorporate an emergency manual release designed for immobilization or service in the event of an EPB failure. Not all vehicles have this feature, and the location and procedure vary by model. Always consult the owner's manual or contact a dealer before attempting any manual release.

When to contact roadside assistance

If the EPB remains engaged or you cannot release it after trying the steps above, do not attempt to drive. Roadside assistance or a tow to a dealership is the safest option to prevent brake damage or an accident.

Summary: An EPB that will not disengage can result from issues ranging from a weak battery to a faulty actuator or software fault. Start with safety, attempt the standard release method, and seek professional service if it remains stuck. A technician can diagnose and fix the root cause, often with a software update or component replacement, and ensure the vehicle can be safely driven again.

What to do if the parking brake won't disengage?

Locate the switch on the parking brake assembly and see if the plunger on it is stuck or broken. You could also disconnect the wires from it which should disable it because it is usually an open circuit (closed when brake is applied).

How do I manually disengage an electronic parking brake?

In a few easy steps, you can release the electronic parking brake, making it easier to move the vehicle.

1. Step 1 – Raise Vehicle.
2. Step 2 – Locate Rear Brake Caliper.
3. Step 3 – Remove Bolts.
4. Step 4 – Remove Parking Brake Motor.
5. Step 5 – Release Brake Caliper.
6. Step 6 – Lower Vehicle.
7. Step 7 – Reverse Procedure.

How do I reset the electronic parking brake?

These lights may vary depending on the make. And model of your vehicle. Typically you'll see a series of blinking or for flashing lights that indicate the reset. Process is in progress. Be patient.

Why will my electronic parking brake not release?

If your electronic parking brake (EPB) won't disengage, try these steps first: repeatedly engage and disengage the brake, use a hairdryer to melt ice, and check your battery. If these simple methods fail, you may need to manually retract the caliper piston, use a diagnostic tool to enter service mode, or seek professional help. 
You can watch this video to learn how to manually release an electronic parking brake: 56sLouison Automotive Inc.YouTube · Jul 8, 2021
Quick fixes

• Cycle the brake: Turn the ignition on and repeatedly press and release the EPB button several times to try to disengage it. 
• Warm the car: If you suspect ice is the problem, start the engine and let the car warm up. You can also use a hairdryer to melt any ice around the brake system. 
• Check the battery: A weak or failing battery can cause various electrical issues, including EPB problems. Have your battery tested and consider replacing it if it's old. 
• Gently rock the vehicle: If safe, shift the car into drive and apply light pressure to the accelerator while trying to disengage the brake. You can also try shifting between drive and reverse. 

Advanced troubleshooting

• Manually retract the caliper piston: This is a more involved process that requires you to get under the car. 
  • Raise the vehicle and support it securely with jack stands. 
  • Locate the EPB motor and remove its fixing bolts, but do not unplug the electrical connector. 
  • Use a socket and wrench to turn the caliper piston adjustment bolt to manually retract the piston and release the brake. 
  • Reinstall the motor (without plugging it in) and lower the vehicle. 
• Use a diagnostic tool: If your car has a service mode, a diagnostic tool can be used to retract the caliper pistons. This is often the recommended method for modern vehicles. 
• Check for physical obstruction: Some EPB issues can be caused by mechanical problems, such as a seized pivot lever in the parking brake cable. Inspecting and lubricating this can be a solution. 

When to call a professional

• If you are uncomfortable with any of these steps, it's best to have a professional mechanic diagnose and repair the issue. 
• They have the right tools and knowledge to diagnose complex problems, such as a faulty EPB motor or wiring issues, without causing further damage. 

This video demonstrates how to retract the caliper piston manually: 1mO'Rileys AutosYouTube · Nov 20, 2020