Put the Electronic Parking Brake into Service Mode

Last updated: June 11, 2026

The Subaru Outback (Mk5/BS, 2015–2019) was the first Outback generation to ditch the foot pedal for a fully electronic parking brake (EPB), with a motor-driven spindle inside each rear caliper. To change the rear pads you must wind those spindles all the way back before the pistons will move. This Gen-5 article gives you the verified method — and unlike the latest Subarus, this generation genuinely offers a no-tool route.

What service mode does and why you need it

When the EPB is applied, an electric motor screws each rear piston outward through a spindle. If you try to compress that piston straight in, you are pushing against the screw thread and the gear train — that is how motors get stripped. Service mode (the factory calls it Brake Maintenance Mode) commands the actuators to retract the spindle fully and disables the EPB so it cannot re-apply. The Gen-5 Subaru service manual documents three legitimate ways to retract the pistons, so you are not forced to buy a scan tool.

Enter service mode — method 1, scan tool

1. Chock the front wheels, ignition ON, engine OFF, foot off the brake.
2. Connect a Subaru-capable bidirectional tool (SSM-III or an aftermarket tool with Subaru EPB support) to the OBD-II port.
3. Open the parking-brake / VDC module, select Brake Maintenance Mode and choose Enter; the rear motors whir as the spindles retract.

Method 2 — windback tool (FSM-approved, no scanner)

1. With the caliper unbolted, fit a right-hand brake windback tool to the piston face.
2. Turn clockwise on BOTH sides — the spindle backs off internally — until the piston stops turning and is fully seated.

Method 3 — remove the actuator motor

1. Undo the two cap screws on the back of the caliper and lift the motor off.
2. Turn the splined shaft with a reverse-Torx/E12 bit clockwise until it hits the hard stop. Fit a new O-ring on reassembly.

Never force the pistons back by hand

Do not C-clamp the piston straight in and never press the brake pedal with a caliper open — the piston can pop out. On the Gen-5 Outback the piston only seats by turning (clockwise) or by electronic retraction. Forcing it in a straight line ruins the EPB actuator. Open the brake-fluid reservoir cap before you seat the pistons so displaced fluid can rise without trapping pressure.

Exit service mode and bed in

Fit the pads, torque the slider bolts, and reverse whichever method you used: with the tool select Exit Maintenance Mode and let it self-test; if you wound back manually, refit any removed motor with a fresh O-ring, then start the car and pump the pedal firm. Fully apply and release the EPB a couple of times so the motors re-tension against the new pads. Bed in with several moderate 30–40 mph stops, then let the brakes cool and confirm the EPB holds on a slope.

Frequently Asked Questions

Do I really need a scan tool for Gen-5 Outback rear pads? No. The factory manual lists a windback tool and motor removal as approved alternatives. A scanner is the cleanest route but not mandatory on this generation.

Which way does the windback tool turn? Clockwise on both rear calipers — use a right-hand-thread tool and spin driver and passenger sides the same direction.

Why won’t it exit maintenance mode? Some scan tools leave the EPB stuck; re-enter the menu and explicitly select Exit, then cycle the switch. A failed pressure test often means a connector is not fully seated.

Should I replace anything when I remove the motor? Yes — fit a new actuator O-ring every time the motor comes off to keep water out.

The EPB light stays on while I work — is that bad? No, that is service mode disabling the brake. It clears when you exit and re-initialise.

If a VDC or parking-brake warning lingers after the job, read the stored code first at autodtcs.com to tell a simple re-init apart from an actuator fault.