Put the Electronic Parking Brake into Service Mode

Last updated: June 12, 2026

Changing the rear brake pads on a Polestar 2 (2020–Present) starts with putting the electronic parking brake (EPB) into service mode. Built on Volvo’s CMA platform, the Polestar 2 uses rear calipers with a built-in electric motor that winds the piston out to hold the car. To fit thicker new pads you must wind that piston fully back, and on this car it has to be done electronically from the centre display — never by force. Here is what to do.

What EPB Service Mode Does

On an ordinary caliper you push the piston straight back. The Polestar 2’s rear piston is driven by a geared EPB actuator, so while the motor is in its applied position the piston is locked. EPB service mode commands both rear motors to wind fully open, retracting the actuator clear of the piston so the caliper can be opened, the pads renewed, and the piston wound back without damage. The function is reached from the car’s centre display.

How to Put the Polestar 2 EPB into Service Mode

1. Park on level ground, chock a front wheel, leave the car in P.
2. Wake the car to active / ignition on (sit in the driver’s seat with the key present; you don’t need to press the brake). Make sure the 12 V battery is healthy — low voltage will stop the routine.
3. Release the parking brake at the EPB switch so it is off.
4. On the centre display, open Settings (the car/cog area), then go to Car → Service and select the EPB service mode / brake maintenance function.
5. Confirm. The rear actuators whir as they wind back; the display reports when service mode is active.
6. Wait for that on-screen confirmation before opening either caliper. The pistons can now be wound back and the pads replaced.

If the option is greyed out, the parking brake is still applied or the battery is low — fix that and try again.

Never Force the Piston — This Ruins the Motor

Do not press or wind the rear piston back by hand, and never use a screw-in wind-back tool. The piston is held by the EPB motor and its gear train; forcing it shears the gears and burns out the actuator, which means an expensive caliper-with-motor replacement. The caliper must be retracted electronically through service mode (or with a Volvo/Polestar VIDA-grade scan tool). Only after the display confirms service mode is active is it safe to touch the piston.

Exiting Service Mode and Bedding In

With the new pads fitted and the calipers torqued up, return to the same EPB service mode screen and select exit / deactivate; the motors wind back out and re-tension on the new pads. If your car exits automatically, cycle the car off and back on, then apply and release the EPB switch once to confirm it grips. Pump the brake pedal several times until firm before moving off. Then bed the pads: from around 30–40 mph make several moderate stops with cooling gaps, and avoid hard braking for the first 100–200 miles so the friction material seats. Because the Polestar 2 brakes lightly in normal driving (regen does most of the slowing), make a point of using the friction brakes occasionally during bed-in.

Frequently Asked Questions

Can I change the Polestar 2 rear pads without a scan tool?

EPB service mode is reachable from the centre display, so the retraction itself doesn’t need a separate scanner. A VIDA-grade tool is only a fallback if the on-screen function won’t run. Polestar still recommends pad work be done by a trained workshop.

Where is the function on the display?

Under Settings → Car → Service, listed as EPB service mode / brake maintenance. The parking brake must be released first or it stays greyed out.

Why won’t service mode activate?

Usually the parking brake is still applied, the car isn’t in P, or the 12 V battery is low. The motors need current to wind back, so the system blocks the routine when voltage is marginal — charge the 12 V battery and retry.

Does regen braking affect how often I change pads?

Yes — one-pedal regen means the friction pads do far less work than on a petrol car, so they often last a long time. But they can corrode or glaze from light use, which is its own reason to inspect and occasionally renew them.

The brake warning stayed on after the job — is that normal?

It can remain until you exit service mode and cycle the EPB. Deactivate service mode, switch the car off and on, then apply and release the parking brake; it should clear. If it doesn’t, a fault code has been stored.

If the EPB warning stays on or a fault is logged afterwards, look up the code on autodtcs.com before booking a workshop.