Put the Electronic Parking Brake into Service Mode

The Lexus IS (Mk3/XE30, 2013–2020) uses an electronic parking brake (EPB): a console switch and a geared electric motor on each rear caliper in place of a handbrake lever. Before you change the rear pads or discs you have to put the EPB into rear brake service (maintenance) mode so the motors retract the pistons and the system stops fighting you. On the IS this is a tool-led procedure: Lexus’s factory route uses Techstream, and a generic OBD EPB scan tool does the same job. There is no reliable owner button trick, so use the tool.

What service mode is and why you need it

Each rear caliper carries a motor that drives the parking-brake nut against the piston. With the EPB live that nut holds the piston applied, so you cannot push it back for thicker new pads. Service mode runs the motors to retract the pistons and disables the EPB so it will not re-apply while the caliper is open. With it active the dash shows a parking-brake warning and the brake will not engage — the clearance you need.

Entering EPB service mode on the IS Mk3

Park on level ground and chock a front wheel. Use a scan tool:

1. Plug a Techstream (or a generic OBD2 tool with a Lexus/Toyota EPB function) into the DLC3 port and set the ignition to ON.
2. Navigate to Chassis → Electric Parking Brake → Maintenance/Utility → Retract Piston (Rear Brake Pad Replacement).
3. Follow the prompts; the rear motors run and retract the pistons. The parking-brake indicator flashes then settles once the mode is set.
4. Switch off and lift the car. The pistons are retracted and the EPB is locked out.

Entering the mode may log DTC C13A7/43 — expected, and cleared with the tool after the job.

Never force the pistons back by hand

The rule that protects your calipers: never wind or force the EPB pistons back with a clamp, a wind-back tool or by hand while the system is live. The piston is driven by a geared motor; forcing it backwards strips the gearset or burns out the motor — a new caliper, not a cheap fix. Retract only electronically with the tool. Once service mode has retracted the pistons there is room to fit the new pads with only light pressure. If a piston still feels tight, stop and confirm the mode actually took.

Exit and bed-in

With the new pads fitted and the wheels back on, use the tool to close service mode and clear any stored EPB code. Then switch the ignition ON, press the brake pedal firmly and apply and release the EPB two or three times with the console switch so the motors re-learn the thicker pads, checking the brake warning clears. Finish with a road bed-in: from about 30 mph (50 km/h) brake firmly but not to a stop, repeat eight to ten times with cooling gaps, then confirm the parking brake holds on a slope.

Frequently Asked Questions

Does every IS Mk3 have the EPB? Yes — the third-generation IS (IS200t/IS300, IS250, IS300h, IS350) uses the console EPB switch in place of the old handbrake lever. There is no lever or foot handbrake on this generation.

Can I do it without a scan tool? A switch-and-pedal sequence works on some older GS models but is not reliable on the XE30 IS, and a failed attempt sets a parking-brake malfunction you then need a tool to clear. A cheap OBD2 EPB tool is the safe route.

Is the IS300h hybrid different? The EPB hardware is the same. Make sure the car is fully OFF (not in READY) before connecting the tool; the retract-and-relearn steps are identical.

Do the pistons press or wind back? The IS service mode retracts the pistons electronically, so you fit the pads against an already-retracted piston — do not clamp or wind against a live EPB.

Why is the parking-brake light still on after the job? It clears once the EPB re-tensions through a full apply-and-release on the new pads and the code is cleared with the tool. A flat 12V battery also blocks the mode — charge it first.

If a warning lamp or stored fault code appears during the job, you can look up what it means on our sister site autodtcs.com.