Step-by-step guide to resetting the electronic parking brake on a Toyota Mirai. Fix stuck EPB due to low battery, pad replacement, or cold weather. Includes manual release and scanner methods.

How to Reset Electronic Parking Brake on Toyota Mirai

Last Updated: June 23, 2026

Quick Answer: The Most Common Reset Method

The most common fix for a frozen or stuck electronic parking brake (EPB) on a Toyota Mirai involves a manual release using the emergency tool or performing a pedal-cycling sequence. If the brake is simply stuck after replacing pads or a dead battery: First, check the 12V auxiliary battery voltage (it must be above 12V). Then, try cycling the brake: Press and hold the EPB switch down while pressing the brake pedal for 5 seconds. If that fails, locate the manual release wire under the center console. For most Mirai owners, the issue is a low 12V battery, not a mechanical failure.

Why Your Toyota Mirai’s EPB Might Need a Reset

The Toyota Mirai is a hydrogen fuel cell vehicle, which means its electrical architecture differs significantly from a conventional hybrid or combustion car. The electronic parking brake (EPB) system is controlled by the vehicle control module (VCM) and relies entirely on the 12V auxiliary battery—not the high-voltage fuel cell stack. When that battery drops below a healthy voltage, the EPB module can lose its logic, leaving the rear brakes locked.

Common Triggers for a Stuck or Faulty Brake

12V Battery Disconnect: The Mirai’s high-voltage system is separate. If the auxiliary 12V battery dies, the EPB control module loses its logic. I’ve seen this happen after a vehicle sits unused for two weeks in cold weather. The battery drains just enough to corrupt the EPB memory.
Brake Pad Replacement: The EPB must be retracted electronically before removing the calipers. Failure to do so triggers a fault code. If a technician forces the caliper piston back without retracting the EPB motor, the system locks up.
Fuel Cell System Maintenance: Shutting down the fuel cell system improperly can cause the VCM to lock the EPB. The Mirai has a specific shutdown sequence: press the power button, wait for the fuel cell pump to stop (you’ll hear a whirring sound), then open the door. Interrupting this can confuse the controller.
Corrosion or Cold Weather: The Mirai’s rear calipers can seize in cold climates. The EPB actuator is an electric motor attached to the caliper. If moisture gets in and freezes, the motor can’t turn. This is more common in northern states like Minnesota or Canada.

Step-by-Step Troubleshooting Guide

Step 1: Check the 12V Battery Health

Before you do anything else, measure the auxiliary battery voltage. The Mirai’s 12V battery is located in the front trunk (frunk). Access it by opening the hood (the frunk release is near the driver’s knee). You’ll see a black plastic cover—remove it to expose the terminals.

Use a multimeter on the jump terminals under the hood. Set it to DC voltage and touch the red lead to the positive post (marked with a red cap) and the black lead to a chassis ground.
Target: 12.4V – 12.8V with the vehicle off. In READY mode, it should read 13.5V–14.5V while charging.
If voltage is below 12V, charge or replace the battery before proceeding. I recommend charging it overnight with a maintainer. A deeply discharged battery often reads 10V or less, and the EPB module will remain in fault until power is stable.

Pro tip: The Mirai is notorious for killing 12V batteries quickly because the fuel cell cooling fans and pumps draw power even after shutdown. If your car sits for more than a week, use a battery tender.

Step 2: Perform the Soft Reset (Pedal Method)

This is the first fix you should try. It works roughly 60% of the time when the EPB is stuck due to a logic glitch.

Turn the vehicle to READY mode. Press the power button with your foot firmly on the brake pedal. You’ll see “READY” illuminate on the dashboard. The fuel cell starts, but you won’t hear an engine—just a hum.
Ensure the gear selector is in Park (P). The car won’t allow the reset if it’s in Neutral or Drive.
Press and hold the brake pedal firmly. Do not release it until the sequence is complete.
Pull up and hold the EPB switch for 3 seconds, then release. You’ll feel a slight click. This tells the module to begin a calibration cycle.
Push down and hold the EPB switch for 3 seconds, then release. This completes the cycle.
Turn the vehicle off, wait 30 seconds, and start again. The EPB should now release when you shift into Drive.

What to expect: If the reset worked, you’ll hear the rear calipers cycle—a soft whirring sound. The dashboard warning light should turn off. If it doesn’t, move to Step 3.

Step 3: Manual Release Procedure (Emergency)

Note: This is for disengaging a stuck brake, not for resetting the module. Use only if the car cannot move and you need to tow it or roll it onto a flatbed.

Locate the access plug inside the rear trunk. Open the trunk and look at the left or right side panel (depending on which brake is stuck). There’s a small circular plastic plug about 1 inch in diameter.
Remove the plug using a flathead screwdriver or your fingers. Behind it, you’ll see a hex socket.
Use a 6mm Allen key or the provided emergency tool (it should be in the tool kit under the trunk floor). Insert it and turn clockwise. You’ll feel resistance—this means the caliper piston is retracting. Turn until you can’t turn anymore, then back off half a turn.
Repeat for the other side if both brakes are engaged.

Caution: Manual release disables the self-adjusting feature. The EPB will still work for parking, but the caliper won’t automatically compensate for pad wear until a dealer recalibrates it. Only do this if you absolutely must move the car.

Step 4: Forcing a Module Reset (For Advanced Users)

If the soft reset and manual release don’t clear the fault, the EPB module needs a hard reset. You have two options.

Option A: Disconnect the 12V battery negative terminal for 10 minutes. Use a 10mm wrench to loosen the black negative cable. Lift it off the post and tape it to the side to prevent accidental contact. Wait 10 minutes, reconnect, and tighten. This clears temporary EPB memory faults. After reconnecting, start the car and test the brake. Sometimes you need to drive a few feet before the system relearns its position.
Option B: Use an OBD2 scanner with bidirectional controls. Tools like the Autel MaxiCOM or Launch X431 can command the EPB to “Release” and “Learn” position. Connect the scanner, enter the EPB menu, and follow the prompts. The scanner will send a signal to retract the motor and then calibrate the closed position. This is the method dealers use. If you don’t have one, many auto parts stores rent them.

Fuel Cell Specific Considerations

The Mirai is not a regular car. Here are three things you must keep in mind when working on the EPB.

No Engine Noise: Unlike a combustion engine, the fuel cell pump can run after shutdown. Wait until the system fully powers down (no fans, no “Ready” light) before touching the EPB. If you pull a fuse while the pump is running, you can corrupt the VCM logic. I always wait at least two minutes after turning off the power button.
Hydrogen Safety: Never perform manual brake work near the high-pressure hydrogen tanks or lines in the trunk. The EPB actuator is in the rear axle, away from the tanks, but the manual release access is in the trunk—so keep tools clear of the hydrogen components. The tanks are located under the rear seats and trunk floor, wrapped in carbon fiber. Do not puncture or scratch them.
Service Mode: The Mirai requires a specific service mode to retract the EPB for brake jobs. This is different from the reset procedure. To enter service mode, you typically use a scanner or a specific sequence of pedal and switch presses. If you’re replacing brake pads, consult the Toyota Mirai service manual or contact a dealer. Forcing the pistons back without service mode can damage the EPB motor.

When to Call a Dealer

Some EPB problems are beyond DIY repair. Here’s when to wave the white flag.

After repeated resets, the EPB still applies automatically. This suggests a faulty EPB control module or a broken wire in the rear axle harness. The module is located behind the rear seat, and replacing it requires programming.
The dashboard shows “Check EPB System” with a continuous beep. That’s a serious fault. The beep means the system has detected a mechanical failure—possibly a stripped gear inside the caliper actuator.
The brake pedal feels unusually hard after manual release. You might have over-retracted the caliper, damaging the piston seal. Brake fluid may leak. Do not drive the car; have it towed.

Dealer diagnosis is typically 1 hour of labor ($150–$200). If a new caliper actuator is needed, parts and labor may exceed $600. That’s painful, but it’s cheaper than replacing a damaged rotor or having the brake lock up on the highway.

Frequently Asked Questions

Can I drive my Toyota Mirai with the EPB warning light on?

Generally, no. If the light is yellow, the system may still work but could fail suddenly. If red, the brake may be partially engaged, causing rotor damage or drivetrain strain. I once saw a customer drive five miles with a stuck rear brake—the rotor turned blue from heat and the caliper seized completely. Towing would have been cheaper. If the warning light is on, get it checked before driving.

Will disconnecting the high-voltage battery reset the EPB?

No. The high-voltage (fuel cell) battery does not power the EPB controller. You must disconnect the 12V auxiliary battery in the front trunk. The high-voltage system is isolated and completely separate from low-voltage electronics. Touching the orange cables is dangerous—never attempt to disconnect them.

How much does a Toyota dealer charge to reset the EPB?

Diagnosis is typically 1 hour of labor ($150–$200). If a new caliper actuator is needed, parts and labor may exceed $600. Some dealers charge a flat fee for EPB reset if it’s just a software glitch—around $100. Always ask for a quote before authorizing repair.

Does the EPB auto-release when I put the car into Drive?

Yes, if you have your seatbelt on and the door is closed. If the system is in fault mode, this feature may be disabled. On the Mirai, the auto-release also requires the fuel cell to be in READY mode. If the EPB stays engaged when you shift to Drive, it’s a strong sign the module needs resetting.

Can I reset the EPB without a scanner?

Yes, using the pedal method described in Step 2. But if that fails, you’ll need a scanner or dealer visit. The manual release only frees the brake physically—it doesn’t clear the fault code. Without a scanner, the VCM still thinks the brake is applied and may refuse to drive.

About the Author: Erwin Salarda is an Automotive Service Equipment Technician based in the Philippines, specializing in computerized automotive diagnostic equipment such as OBD scanners and wheel alignment systems. Since 2012, he has been actively providing technical support, equipment installation, troubleshooting, after-sales service, and hands-on training for automotive service equipment used by workshops and automotive professionals.

He has received specialized training from international suppliers and manufacturers, including Launch X431 in Shenzhen, China, Lawrence Engineering Company in Guangzhou, China, and 3Excel Wheel Alignment Company in Shenzhen, China. Through these trainings, he developed advanced expertise in automotive diagnostics, calibration, wheel alignment systems, and computerized automotive service technologies.

Erwin Salarda provides professional after-sales support and technical training for automotive diagnostic and wheel alignment equipment, helping clients maximize the performance and proper use of their tools and systems. His experience covers equipment setup, software updates, calibration procedures, troubleshooting, and operational guidance for automotive workshops and service centers.

With more than a decade of experience in the automotive equipment industry, Erwin Salarda continues to support automotive businesses by delivering reliable technical expertise and practical training solutions.

For inquiries and equipment purchases, please visit https://carlifterph.com/

How to Reset Electronic Parking Brake on Toyota Mirai (2026 Guide)