Electronic parking brakes (EPB) are now standard on most modern vehicles. Unlike the old cable-operated handbrake, an EPB uses a small electric motor to clamp the rear brake caliper. This is great for convenience but it creates a problem when it comes time to service the rear brakes: you cannot manually wind back the caliper piston the way you used to. Without the right tool, you are stuck.

This is one of the most common reasons mechanics and DIYers need a proper scan tool rather than a basic code reader. Here is what you need to know.

Why you cannot just compress the piston manually

On a standard brake caliper, you wind the piston back with a cube tool or a brake piston wind-back kit. Simple and cheap. On an EPB caliper, the motor is mechanically linked to the piston. If you try to force it back without retracting the motor first, you will damage the motor or the caliper mechanism. Some vehicles will also throw a fault code or lock the system out entirely.

The correct procedure is to retract the motor electronically before you compress the piston, then re-engage it after the new pads are fitted.

What you need

You need a scan tool that supports EPB service functions. This is sometimes listed as EPB reset, brake pad reset, or EPB retract/apply. Basic OBD2 code readers do not have this function. You need at least a mid-range scan tool with special service functions.

Tools from our range that support EPB service include the:  

Topdon Topscan Pro

Topdon AD900BT 

Launch X431 Pros Elite

Autel MX900 Autel MP900 or Higher

Autel MK808K-BT, Autel MS906 Pro, Launch X431 ProS V5.0, and Topdon Phoenix Max,  among others.

The general process

The exact steps vary between vehicle brands and models, but the general process is consistent across most vehicles.

Step 1 — Connect the scan tool

Plug your scan tool into the OBD2 port (usually under the dashboard on the driver's side). Turn the ignition to the on position. You do not need the engine running for this procedure.

Step 2 — Select the vehicle

Use auto VIN or manually select your vehicle make, model, and year. Navigate to the brake system or EPB module.

Step 3 — Enter service mode and retract the caliper

Look for an option called EPB service, brake pad replacement, or EPB retract. On most tools this will be under Special Functions or Service Functions. Select it and follow the on-screen prompts.

The scan tool will command the EPB motor to retract the piston fully into the caliper. You will often hear a short whirring or clicking sound from the caliper as it retracts. Once complete, the scan tool will confirm the caliper is in service position.

Step 4 — Replace the brake pads

With the caliper in service mode, you can now compress the piston using a standard brake piston tool. Fit your new brake pads as normal.

Step 5 — Re-initialise the EPB

Once the pads are fitted and the caliper is reassembled, go back to the scan tool and run the EPB initialise or brake pad break-in function. This re-engages the motor to the correct position for the new pad thickness and resets any brake pad wear indicators if applicable.

On some vehicles you will also need to reset the brake pad wear sensor separately.

Common issues to watch for

• Make sure the vehicle battery is in good condition before starting. The EPB motor draws reasonable current and a weak battery can cause errors mid-procedure.
• Do not disconnect the scan tool while the procedure is running. Interrupting the process can leave the caliper in an intermediate position or stuck in service mode.
• Some vehicles require the handbrake to be applied or released to a specific position before the procedure will start. Follow the on-screen prompts carefully.
• European vehicles, particularly VAG group (Volkswagen, Audi, Skoda, Seat), BMW, and Mercedes, often have more steps than Japanese or Korean vehicles. Budget a bit more time on these.

Is EPB reset the same as brake bleed?

No. EPB reset is about retracting and re-initialising the caliper motor for pad replacement. Brake bleeding is a separate function (sometimes called ABS bleed or brake flush) that cycles the ABS solenoids to help push fluid through the system. Some scan tools combine both into a brake service menu, but they are different procedures.

Vehicles most commonly requiring a scan tool for EPB

Almost all modern European vehicles from 2012 onwards require a scan tool for EPB service. Japanese and Korean vehicles started adopting EPB from around 2015, and most new Australian-delivered vehicles across all brands now have it. If you are working on a Mazda CX-5, Toyota RAV4, Hyundai Tucson, Ford Ranger, VW Golf, BMW 3 Series, or similar from the last decade, there is a good chance you need EPB reset capability.

Bottom line

EPB reset is one of the most frequently used special functions on a workshop scan tool. If you are servicing modern vehicles regularly and you do not have a tool that supports it, you are either sending jobs away or doing them the hard way. A scan tool with EPB support pays for itself quickly.

Not sure which tool covers your vehicle range? Check our range or get in touch with our Australian support team and we will point you in the right direction.