Put the Electronic Parking Brake into Service Mode

Last updated: June 12, 2026

The Peugeot 308 (Mk3/P51, 2021–Present) uses a fully electronic parking brake on its EMP2 V3 platform: each rear caliper carries its own electric motor, and the only control is the P rocker switch on the centre console. There is no cable and no manual lever. To change the rear pads you first have to drive those caliper motors into a maintenance position electronically, and on this generation that is a tool-based job rather than an owner button sequence.

What service mode does and why the 308 Mk3 needs it

When the parking brake is set, each rear motor has wound its spindle forward to press the pad onto the disc. Day to day the system only retracts slightly, nowhere near enough to admit a new full-thickness pad, and it can re-clamp the moment the brake control unit powers up. Service mode — PSA’s caliper dismantling or replacement position — commands both motors to wind fully back and then keeps the EPB inactive so it can’t clamp while the caliper is apart.

To be straight about it: the 308 Mk3 has no dashboard menu or button combination to do this. You need the factory Diagbox software or a generic OBD scan tool with verified PSA/Stellantis electronic parking brake coverage. Plug into the OBD socket under the dash, select the EPB / rear-brake module, and run the pad replacement routine. The tool retracts the motors but does not push the hydraulic piston back — that part stays manual.

Retract the caliper safely

1. Park on level ground, chock the front wheels, and leave the ignition off until the tool prompts you.
2. Connect Diagbox (or a PSA-capable EPB tool) to the OBD port and select the electronic parking brake module.
3. Run the rear-brake pad-replacement routine so both motors move to the dismantling position and the EPB is disabled.
4. Raise the car, remove the rear wheels, unbolt the caliper, and push the piston straight in with a piston-press or a flat-plate clamp.
5. Fit the new pads, rebuild the caliper, and refit the wheels.

Critical warning: never force the EPB pistons back by hand and never use a rotating wind-back tool. On the 308 Mk3 the motor caliper retracts on a fine internal screw thread — if you turn or hammer the piston you shear that thread and destroy the caliper. Retract electronically with the tool first, then push the piston in a straight line only.

Exit service mode and bed in the pads

With the new pads in place, run the tool’s EPB end-of-replacement / calibration routine so the motors re-learn the new pad thickness and the handbrake clamps correctly. Before driving, press the brake pedal firmly several times to seat the pistons against the discs — the first pull feels long until they take up. Apply and release the P switch a couple of times to confirm it works, check the brake-fluid level, and clear any stored EPB fault codes with the tool. Brake gently for the first 200–300 km so the new friction material beds in evenly.

Frequently Asked Questions

Does the 308 Mk3 have a true electronic parking brake?
Yes — motor-on-caliper EPB operated by the centre-console P switch, with no cable or lever.

Can I retract the brake from the touchscreen or a button sequence?
No. There is no owner-accessible service routine. You need Diagbox or a scan tool with genuine PSA EPB support to command the dismantling position.

Why can’t I wind the piston back?
The motor screw has already retracted, so the 308 piston is pushed straight in. Rotating it winds against the screw and strips the internal thread, ruining the caliper.

Is recalibration mandatory after pads?
Yes. Run the calibration / end-of-replacement routine so the motors learn the new pad thickness; skip it and the handbrake may hold poorly or log a fault.

I get an EPB warning after the job — how do I clear it?
Re-run the calibration routine, cycle the P switch, and clear codes with the tool. A lingering warning usually means service mode wasn’t exited cleanly.

If your 308 Mk3 is showing an ABS or EPB warning lamp and you want to identify the stored code before working on the brakes, you can decode it at autodtcs.com.