These instructions apply to the Lexus NX Mk1 (Z1) 2014-2021.
For other models, please choose your vehicle here.
The Lexus NX (Z1/AZ10, 2014–2021) 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 pad-replacement (maintenance) mode so the motors retract and the system stops fighting you. On the NX 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 pad-replacement mode is and why you need it
Each rear caliper carries a motor that drives the parking-brake mechanism against the piston. With the EPB live it holds the piston applied, so you cannot service the caliper. Pad-replacement mode runs the motors back 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. Important on the NX: this mode releases the parking-brake actuator but does not push the caliper piston out — the rear piston is a screw type and must be wound back with the correct tool once the actuator is released.
Entering EPB service mode on the NX Z1
Park on level ground, chock a front wheel and switch Brake Hold OFF. Use a scan tool:
- Plug a Techstream (or a generic OBD2 tool with a Lexus/Toyota EPB function) into the DLC3 port and set the ignition to ON.
- Navigate to Chassis → Electric Parking Brake → Utility → Rear Brake Pad Replacement (Check Mode).
- Press and hold the brake pedal, hold the EPB switch down for five seconds and keep holding the pedal until the mode engages.
- The parking-brake indicator flashes about four times a second while the actuators run, then drops to about one flash a second once it is set. Switch off and lift the car.
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 while the system is live. Because the NX uses a screw-type rear piston, you must first release the actuator with the tool, then wind the piston back with a proper wind-back tool (turn while pushing). Forcing the screw against a live, applied actuator strips the mechanism or burns out the motor — a new caliper, not a cheap fix. Many techs also disconnect the parking-brake actuator connector before rotating the caliper up, to avoid damaging it. Retract only electronically, then wind the screw — never clamp or hammer it.
Exit and bed-in
With the new pads fitted and the wheels back on, use the tool to close pad-replacement 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 NX Z1 have the EPB? Yes — the first-generation NX (NX200t, NX300, NX300h) uses the console EPB switch with Brake Hold across the range. There is no lever or foot handbrake.
Do the pistons press in or wind back? They wind back. The rear caliper uses a screw-type EPB piston, so after releasing the actuator you turn the piston clockwise while pushing with a wind-back tool. A straight clamp will not seat it and risks damage.
Can I do it without a scan tool? A switch-and-pedal sequence exists, but it is unreliable on the NX 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.
Where is the parking-brake ECU? In the left rear cargo area — useful to know if you are chasing a fault, but you do not need to touch it for a pad change.
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 C13A7/43 is cleared with the tool. If it stays lit, scan for a stored code.
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.
Independent guide — not affiliated with Lexus. Always follow your official service manual and safety precautions. Read our full disclaimer.